CHAPTER-1-12.pdf

Summary Cognitive Psychology: Sternberg 7th edition Chap. 1-12 Chapter 1 1. Cognitive Psychology Defined = study of how people perceive, learn, remember, and think about information – Heuristic = Mental shortcut to process information – Dialectic: back-and-forth- development process a. Thesis b. Antithesis c. synthesis – Culture influences cognitive processes e.g. intelligence (Nisbett: east – west) 2. Philosophical Origins of Psychology: Rationalism versus Empiricism – origins of cognitive psychology: a. philosphy: method of introspection b. physiology: empirical method – two philosophical perspectives: a. rationalism: goes back to Plato, route to knowledge is through logical analysis and thinking, prominent thinker: Descartes, cogito ergo sum b. empiricism: goes back to Aristotle, route to knowledge via empirical observation prominent thinker: Locke, tabula rasa synthesis: Immanuel Kant 3. Psychological Origins of Cognitive Psychology 3.1 Early Dialectics in the Psychology of Cognition dialectic development of modern psychology – Structuralism vs Functionalism a. Structuralism: first major school of psychology; seeks to unterstand the structure of the mind and its perceptions by analyzing those perceptions into their constituent components (affection, attention, memory, sensation) founder of structuralism: Wilhelm Wundt, who used the method of introspection (=conscious observation of one’s own thinking processes) → problems of introspection: a. people may not know their own thought process or put them intto words b. information may be inaccurate c. paying attention may alter thought process Edward Titchener: student of Wundt, brought structuralism to the US, used method of introspection b. Functionalism: focus on the processes of thought rather than on its contents: seeks to understand what people do and why they do it; developed as an alternative to structuralism; Functionalists were interested in practical application of research and used a variety of methods → Pragmatism: knowledge is validated by its usefulness William James: guided functionalism towards pragmatism; author of Principles of Psychology John Dewey: another early pragmatist who infliuenced contemporary cognitive psychology 3.2 From Associationism to behaviourism – Associationism = influental way of thinking in early psychology: Associationism examines how elements of the mind, such as events or ideas, can become associated with one another in the mind to result in a form of learning associations may result from: a. contiguity (associating things that tend to occur together at about the same time); b. similarity (associating things with similar features or properties); or c. contrast (associating things that show polarities, such as hot/cold, light/dark, day/night). Hermann Ebbinghaus: first experimenter to apply associationist principles systematically; studied his own mental processes → studied how people remember through rehearsal → repetition fixes mental associations Edward Lee Thorndike: satisfaction is key to formin associations → law of effect: A stimulus will tend to produce a certain response over time if an organism is rewarded for that response – Behaviourism: focuses only on the relation between observable behaviour and environmental events or stimuli; may be considered an extreme version of associatonism: focuses on association between environment and behaviourism Ivan Pavlov: classical conditioning, studies involunatry reactions in dogs → paved the way for behaviourism classical conditioning requires contiguity (stimuli appear at the same time) and contingency (stimuli are presented together contingently) John Watson: „father“ of radical behaviourism; believd that psychology should concentarte only on on observable behaviour, not on mental states (thinking as subvocalized speech) lots of behaviourist research is conducted on animals → question, whether research can be generalized for humans B.F. Skinner: believed that virtually all forms of human behaviour, not just learning, could be explained by reactions to the environment → operant conditioning; applied his principles to learning, language acquisition and problem solving - – Criticism of Behaviourism: a. behaviourism did not account as well for complex mental activities, such as language learning and problem solving b. „psychologists wanted to know what went on inside the head „ c. using the techniques of behaviourism to study nonhuman animals was often easier than studying human ones – Opening the Black Box: behaviourists unterstand mind as input – blackbox – output mechanism, whose internal processes cannot be described or observed Edward Tolman: thought that understanding behaviour required taking into account the purpose of, and the plan for, the behaviour → all behaviour is directed toward a goal; forefather of modern cognitive psychology Albert Bandura: learning appears to result not merely from direct rewards for behaviour, but it also can be social, resulting from observations of the rewards or punishments given to others → learning by examples (models) can be seen in various animals and humans, infants as well as adults 3.3 Gestalt Psychology: Gestalt Psychology states that we best understand psychological phenomena when we view them as organized, structured wholes → we cannot fully understand behaviour when we only break phenomena down into smaller parts ; avid critic of behaviourism “the whole is more than the sum of its parts” 4. Emergence of Cognitive Psychology – Cognitivism: „cognitive revolution“ in 1950s → belief that most human behaviour explains how people think; rejects behaviourist idea that psychology should not study mental processes Cognitivism can be viewed as a syntheis of behaviourism (precise quantitative analysis) and Gestaltism (emphasis on internal mental processes) Karl Spencer Lashley: Watson's former student, considered the brain to be an active, dynamic organizer of behaviour → sought to understand how the macro-organization of the human brain made possible complex, planned activities Donald Hebb: proposed the concept of cell assemblies (coordinated neural structures that develop through frequent stimulation) as the basis for learning in the brain Noam Chomsky: wrote an article against Skinners' theory of language acquisition → stressed the biological basis and the creative potential of language; pointed out the infnite numbers of sentences we can produce – 1950's: machines could be programmed to intelligently process information Alan Turing: Human and machine communication won't be distuingishable → Turing test – Artifcial intelligence (AI): systems that show intelligence and, particularly, the intelligent processing of information – 1960's: development of psychobiology/cognitive neuroscience – George Miller: Magic Number Seven (e.g. short term memory), channel capacity (the upper limit with which an observer can match a response to information given to him) – Ulrich Neisser: Cognitive Psychology – 1970's: – Jerry Fodor: Modularity of Mind = the mind has distinct modules, or special-purpose systems, to deal with linguistic and, possibly, other kinds of information 5. Research Methods – Goals: data gathering, data analysis, theory development, hypothesis formulation, hypothesis testing, application to settings outside the research environment. – Theory = an organized body of general explanatory principles regarding a phenomenon, usually based on observations – hypothesis = tentative proposals regarding expected empirical consequences of the theory, such as the outcomes of research – Statistical signifcance indicates the likelihood that a given set of results would be obtained if only chance factors were in operation a. laboratory/controlled experiments: – Independent variables are aspects of an investigation that are individually manipulated – Dependent variables are outcome responses, the values of which depend on how one or more independent variables inﬂuence or aﬀect the participants – control variables: irrelevant variables that are held constant – Confounding variables: a type of irrelevant variable that has been lef uncontrolled in a study – ! The experimenter also must randomly assign participants to the treatment and control conditions ! – Common variables: percent correct (error rate) and reaction time → subtraction method = estimating the time a cognitive process takes by subtracting the amount of time information processing takes with the process from the time it takes without the process – inference of causal link legitimate with experimental method – correlation: Pearson's r between 0 and 1 → causality cannot be inferred b. neuroscientific research – relationship between cognitive performance and cerebral events and structures – three categories: a. postmortem study of the brain (e.g. how lesions influence cognitive defects) b. studying images showing structures of or activities in the brain of an individual who is known to have a particular cognitive deficit c. techniques for obtaining information about cerebral processes during the normal performance of a cognitive activity c. self-reports, case studies, naturalistic observations – self-reports = (an individual’s own account of cognitive processes) case studies = (in-depth studies of individuals) naturalistic observation = (detailed studies of cognitive performance in everyday situations and nonlaboratory contexts) → useful for hypothesis formulation – ! Data based on self-reports may be unreliable due to intentional or unintentional misreports ! – Verbal protocol: participants describe aloud all their thoughts and ideas during the performance of a given cognitive task → Problem: Cognitive processes may be altered by the act of giving the report – Case studies and naturalistic observation: high ecologic validity = the degree to which particular fndings in one environmental context may be considered relevant outside of that context d. computer simulation and AI – In computer simulations, researchers program computers to imitate a given human function or process , e.g. Computer program that plays chess → three options: a. brute force: algorithm performs very efficiently, but unlike humans b. algorithm tries to imitate human thought processing c. a combination of the two – Cognitive Science = cross- disciplinary feld that uses ideas and methods from cognitive psychology, cognitive neuroscience, AI, philosophy, linguistics, and anthropology SUMMARY 1. What is cognitive psychology? Cognitive psychology is the study of how people perceive, learn, remember, and think about information. 2. How did psychology develop as a science? Beginning with Plato and Aristotle, people have contemplated how to gain understanding of the truth. Plato held that rationalism offers the clear path to truth, whereas Aristotle espoused empiricism as the route to knowledge. Centuries later, Descartes extended Plato’s rationalism, whereas Locke elaborated on Aristotle’s empiricism. Kant offered a synthesis of these apparent opposites. Decades after Kant proposed his synthesis, Hegel observed how the history of ideas seems to progress through a dialectical process. 3. How did cognitive psychology develop from psychology? By the twentieth century, psychology had emerged as a distinct field of study. Wundt focused on the structures of the mind (leading to structuralism), whereas James and Dewey focused on the processes of the mind (functionalism). Emerging from this dialectic was associationism, espoused by Ebbinghaus and Thorndike. It paved the way for behaviourism by underscoring the importance of mental associations. Another step toward behaviourism was Pavlov’s discovery of the principles of classical conditioning. Watson and, later, Skinner were the chief proponents of behaviourism. It focused entirely on observable links between an organism’s behaviour and particular environmental contingencies that strengthen or weaken the likelihood that particular behaviours will be repeated. Most behaviourists dismissed entirely the notion that there is merit in psychologists trying to understand what is going on in the mind of the individual engaging in the behaviour. Tolman and subsequent behaviourist researchers noted the role of cognitive processes in inﬂuencing behaviour. A convergence of developments across many fields led to the emergence of cognitive psychology as a discrete discipline, spearheaded by such notables as Neisser. 4. How have other disciplines contributed to the development of theory and research in cognitive psychology? Cognitive psychology has roots in philosophy and physiology, which merged to form the mainstream of psychology. As a discrete field of psychological study, cognitive psychology also profited from cross-disciplinary investigations. Fields relevant to cognitive psychology include linguistics (e.g., How do language and thought interact?), biological psychology (e.g., What are the physiological bases for cognition?), anthropology (e.g., What is the importance of the cultural context for cognition?), and technological advances like artificial intelligence (e.g., How do computers process information?). 5. What methods do cognitive psychologists use to study how people think? Cognitive psychologists use a broad range of methods, including experiments, neuroscientifc techniques, self-reports, case studies, naturalistic observation, and computer simulations and artifi cial intelligence. 6. What are the current issues and various felds of study within cognitive psychology? Some of the major issues in the feld focus on how to pursue knowledge. Psychological work can be done by using both rationalism (which is the basis for theory development) and empiricism (which is the basis for gathering data); by underscoring the importance of cognitive structures and of cognitive processes; by emphasizing the study of domain-general and of domain-specific processing; by striving for a high degree of experimental control (which better permits causal inferences) and for a high degree of ecological validity (which better allows generalization of findings to settings outside of the laboratory); and by conducting basic research seeking fundamental insights about cognition and applied research seeking eﬀective uses of cognition in real-world settings. Although positions on these issues may appear to be diametrical opposites, often apparently antithetical views may be synthesized into a form that oﬀers the best of each of the opposing viewpoints. Cognitive psychologists study biological bases of cognition as well as attention, consciousness, perception, memory, mental imagery, language, problem solving, creativity, decision making, reasoning, developmental changes in cognition across the life span, human intelligence, artifcial intelligence, and various other aspects of human thinking. Chapter 2 1. Cognition in the Brain: The Anatomy and Mechanisms of the Brain 1.1 Gross Anatomy of the Brain: Forebrain, Midbrain, and Hindbrain – Names come from structure of brain in development → Initially, the forebrain is generally the farthest forward, toward what becomes the face. The midbrain is next in line. And the hindbrain is generally farthest from the forebrain, near the back of the neck → relative orientations change as child develops a. Forebrain (includes cerebral cortex, the basal ganglia, the limbic system, the thalamus, and the hypothalamus): – cerebral cortex: outer layer of cerebral hemispheres; essential for thinking and other mental processes – basal ganglia: crucial to motor function – limbic system (important for emotion, motivation, memory, and learning): a. septum (anger and fear) b. amygdala: emotion, anger and aggression, fear, perception of emotional stimuli; malfunction is possibly related to autism) c. hippocampus: memory formation, seeing relationships among items, spatial relations; damage → inabilty to form new memories – thalamus: relays incoming sensory information to corresponding brain area → most sensory information passes through thalamus; is divided into nuclei – hypothalamus: regulates behaviour related to species survival: fighting, feeding, ﬂeeing, and mating (4F); regulation of emotion and stress reaction, plays a role in sleep; b. Midbrain – control of eye movement and coordination – reticular activating system (RAS) = network of neurons essential to regulating consciousness, including sleep; wakefulness; arousal; attention to some extent; and vital functions, such as heartbeat and breathing – brainstem = hindbrain, along with the thalamus, midbrain, and hypothalamus; connects forebrain to spinal cord → brain death based on brainstem function c. Hindbrain (medulla oblongata, pons, cerebellum) – medulla oblongata controls heart activity and largely controls breathing, swallowing, and digestion; place where nerves from right bodysite cross to left side of brain and vice versa – pons contains neural fbers that pass signals from one part of the brain to another. – Cerebellum controls bodily coordination, balance, and muscle tone, as well as some aspects of memory involving procedure-related movements – The prenatal development of the human brain roughly corresponds to the evolutionary development of the human brain within the species as a whole (hindbrain, then midbrain, then forebrain) 1.2 Cerebral Cortex and Localization of Function Cerebral Cortex: – enables planning, coordination of thoughts and actions, visual and acoustic perception and use of language – forms a 1- to 3-millimeter layer that wraps the surface of the brain, convolutions include three elements: a. Sulci: Small grooves b. Fissures: large grooves c. gyri: bulges between adjacent sulci or fissures → increased surface area – Cerebral Cortex consists of gray matter (grayish neural-cell bodies), underlying structure consists mostly of white matter (white, myelinated axons) Hemispheric Specialization – Two cerebral hemispheres with different specializations; correlate to opposite half of the body (contralateral), but sometimes ipsilateral (to the same side), e.g. odours – corpus callosum connects both hemispheres – Marc Dax: Found Specialization of left hemisphere for language – Paul Broca: Identified Broca Areal for Speech (Speech production) – Carl Wernicke: Identified Wernicke Areal (Speech comprehension) – Roger Sperry: Argued that each hemisphere behaves like a seperate brain – split-brain patients : patients with severed corpus callosum a. left hemisphere: speech, language comprehension,movement, examination of pst experiences, analytical processing b. right hemisphere: spacial visualization, spatial operation, does have semantic knowledge, self-recognition, holistic processing → lateralization can vary (left handers, differences men-women) Cerebral Lobes - four lobes (largely arbitrary anatomical regions divided by fissures): a. frontal lobe: – motor processing and higher thought processes, such as abstract reasoning, problem solving, planning, and judgment → critical in producing speech – prefrontal cortex: involved in complex motor control and tasks that require integration of information over time – primary motor cortex: planning, control, and execution of movement → Control of the various kinds of body movements is located contralaterally on the primary motor cortex; similar inverse mapping occurs from top to bottom ( homunculi maps) b. parietal lobe (upper back portion): – somatosensory processing, perception of space and relationship to space, consciousness and paying attention – primary somatosensory cortex: receives information from the senses about pressure, texture, temperature, and pain c. temporal lobe (below the parietal lobe) – auditory processing and comprehending language, retaining visual memories d. occipital lobe (back) – visual processing: numerous visual areas, each specialized to analyze specifc aspects of a scene, including color, motion, location, and form – Projection areas: areas in the lobes in which sensory processing occurs – visual cortex is primarily in the occipital lobe – rostral, ventral, caudal, and dorsal: used to describe areas in the brain: a. Rostral refers to the front part of the brain (literally the “nasal region”). b. Ventral refers to the bottom surface of the body/brain (the side of the stomach). c. Caudal literally means “tail” and refers to the back part of the body/brain. d. Dorsal refers to the upside of the brain (it literally means “back,” and in animals the back is on the upside of the body). 1.3 Neuronal Structure and Function – neuron has four basic parts: a. soma (cell body): contains the nucleus, is responsible for the life of the neuron and connects the dendrites to the axon b. dendrites: branchlike structures that receive information from other neurons c. axon: long, thin tube that extends (and sometimes splits) from the soma and responds to the information, when appropriate, by transmitting an electrochemical signal, which travels to the terminus (end), where the signal can be transmitted to other neurons myelin: white, fatty substance that surrounds some of the axons of the nervous system, which accounts for some of the whiteness of the white matter of the brain. The more an axon is myelinated, the faster signals can be transmitted → distributed in segments broken up by nodes of Ranvier = small gaps in the myelin coating along the axon, which increase conduction speed d. terminal buttons: small knobs found at the ends of the branches of an axon that do not directly touch the dendrites of the next neuron the synapse serves as a juncture between the terminal buttons of one or more neurons and the dendrites – Neurotransmitters are chemical messengers that transmit information across the synaptic gap to the receiving dendrites of the next neuron; three types: a. monoamine neurotransmitters b. amino-acid neurotransmitters c. neuropeptides – Acetylcholine: memory functions, sleep and arousal – Dopamine: attention, learning, and movement coordination, motivational processes, “dopamine theory of schizophrenia” – Serotonine: eating behaviour and body-weight regulation → anorexia; aggression and regulation of impulsivity 2. Viewing the Structures and Functions of the Brain 2.1 Postmortem Studies – researchers may be able to trace a link between an observed type of behaviour and anomalies in a particular location in the brain, e.g. Broca's patient Tan 2.2 Studying Live Nonhuman Animals – single-cell recordings: researchers insert a thin electrode next to a single neuron in the brain of an animal, then record the changes in electrical activity that occur in the cell when the animal is exposed to a stimulus – lesioning: surgically removing or damaging part of the brain—to observe resulting functional deficits – genetic knockout procedures: by using genetic manipulations, animals can be created without certain kinds of brain cells or receptors 2.3 Studying Live Humans Electrical Recordings: – Electroencephalograms (EEGs): recordings of the electrical frequencies and intensities of the living brain, typically recorded over relatively long periods → study of brainwave activity – event-related potential (ERP): record of a small change in the brain’s electrical activity in response to a stimulating event → cancel out the eﬀects of noise by averaging out activity that is not task-related; can be used to examine developmental changes in cognitive abilities Static Imaging Techniques: – angiogram and CT scan: uses X-Ray for the observation of large abnormalities of the brain, such as damage resulting from strokes or tumor → CT scan consists of several X-ray images of the brain that result in a three-dimensional image → aim of an angiography is to examine the blood ﬂow – magnetic resonance imaging (MRI): reveals high-resolution images of the structure of the living brain by computing and analyzing magnetic changes in the energy of the orbits of nuclear particles in the molecules of the body; two kinds: a. structural MRI: images of the brain’s size and shape b. functional MRI: parts of the brain that are activated when a person is engaged in a particular task Metabolic Imaging: – relies on changes that take place within the brain as a result of increased consumption of glucose and oxygen in active areas of the brain → active areas have higher consumption – subtraction method: two diﬀerent measurements, one taken while the subject was involved in control activity, and one taken when the subject was engaged in the task of interest → difference between these two measurements equals the additional activation; but: the subtraction technique reveals net brain activity for particular areas. It cannot show whether the area’s eﬀect is positive or negative (excitatory or inhibitory)! – PET Scans: measure increases in oxygen consumption in active brain areas during particular kinds of information processing; are not highly precise because they require a minimum of about half a minute to produce data regarding glucose consumption – Functional magnetic resonance imaging (fMRI): uses magnetic felds to construct a detailed representation in three dimensions of levels of activity in various parts of the brain at a given moment in time; less invasive and higher temporal resolution than PET – pharmacological MRI (phMRI): combines fMRI methods with the study of psychopharmacological agents → examine the influence and role of particular psychopharmacological agents on the brain – diﬀusion tensor imaging (DTI): examines the restricted dispersion of water in tissue and, of special interest, in axons → measures how far protons have moved in a particular direction within a specifc time interval; has been useful in the mapping of the white matter of the brain and in examining neural circuits – Transcranial magnetic stimulation (TMS): temporarily disrupts the normal activity of the brain in a limited area → can imitate lesions in the brain or stimulate brain regions; restricted to brain regions that lie close to the surface of the head → possible to examine causal relationships – Magnetoencephalography (MEG): measures brain activity from outside the head (similar to EEG) by picking up magnetic felds emitted by changes in brain activity → allows localization of brain signals – functional transcranial Doppler sonography (fTCD): uses ultrasound technology to track the velocity of blood ﬂow in the brain; the resolution of fTCD is superior to techniques such as PET – Near-infrared spectroscopy (NIRS): can monitor blood ﬂow in the prefrontal cortex and the amount of oxygen in the blood Brain Disorders 3.1 Stroke – occur when the ﬂow of blood to the brain undergoes a sudden disruption → loss of cognitive functioning – two kinds: a. ischemic stroke: occurs when a buildup of fatty tissue occurs in blood vessels over a period of years, and a piece of this tissue breaks oﬀ and gets lodged in arteries of the brain b. hemorrhagic stroke: occurs when a blood vessel in the brain suddenly breaks – symptoms: – numbness or weakness in the face, arms, or legs (especially on one side of the body) confusion and difculty speaking or understanding speech vision disturbances in one or both eyes dizziness, trouble walking, or loss of balance or coordination severe headache with no known cause 3.2 Brain Tumors (neoplasms) – can occur in either the gray or the white matter – two types: a. Primary brain tumors: start in the brain b. Secondary brain tumors: start somewhere else – can be benign (no cancer cells) or malignant (cancer cells) – common symptoms: – headaches (usually worse in the morning) nausea or vomiting changes in speech, vision, or hearing problems balancing or walking changes in mood, personality, or ability to concentrate problems with memory muscle jerking or twitching (seizures or convulsions) numbness or tingling in the arms or legs 3.3 Head Injuries – two types: a. closed-head injuries: skull remains intact, but there is damage to the brain b. open-head injuries: skull does not remain intact – Loss of consciousness is a sign that there has been some degree of damage to the brain – Symptoms: – abnormal breathing disturbance of speech or vision pupils of unequal size weakness or paralysis dizziness neck pain or stiﬀness → Cognitive symptoms can vary widely, depending on the area of the brain that is aﬀected SUMMARY 1. What are the fundamental structures and processes within the brain? Te nervous system, governed by the brain, is divided into two main parts: the central nervous system, consisting of the brain and the spinal cord, and the peripheral nervous system, consisting of the rest of the nervous system (e.g., the nerves in the face, legs, arms, and viscera). 2. How do researchers study the major structures and processes of the brain? For centuries, scientists have viewed the brain by dissecting it. Modern dissection techniques include the use of electron microscopes and sophisticated chemical analyses to probe the mysteries of individual cells of the brain. Additionally, surgical techniques on animals (e.g., the use of selective lesioning and single-cell recording) often are used. On humans, studies have included electrical analyses (e.g., electroencephalograms and eventrelated potentials), studies based on the use of X-ray techniques (e.g., angiograms and computed tomograms), studies based on computer analyses of magnetic felds within the brain (magnetic resonance imaging), and studies based on computer analyses of blood ﬂow and metabolism within the brain (positron emission tomography and functional magnetic resonance imaging) (Sousa, 2011). 3. What have researchers found as a result of studying the brain? The major structures of the brain may be categorized as those in the forebrain (e.g., the all-important cerebral cortex and the thalamus, the hypothalamus, and the limbic system, including the hippocampus), the midbrain (including a portion of the brainstem), and the hindbrain (including the medulla oblongata, the pons, and the cerebellum).thehighly convoluted cerebral cortex surrounds the interior of the brain and is the basis for much of human cognition.thecortex covers the lef and right hemispheres of the brain. they are connected by the corpus callosum. In general, each hemisphere contralaterally controls the opposite side of the body. Based on extensive split- brain research, many investigators believe that the two hemispheres are specialized: In most people, the lef hemisphere primarily controls language.theright hemisphere primarily controls visuospatial processing.thetwo hemispheres also may process information diﬀerently. Another way to view the cortex is to identify differences among four lobes. Roughly speaking, higher thought and motor processing occur in the frontal lobe. Somatosensory processing occurs in the parietal lobe. Auditory processing occurs in the temporal lobe, and visual processing occurs in the occipital lobe. Within the frontal lobe, the primary motor cortex controls the planning, control, and execution of movement. Within the parietal lobe, the primary somatosensory cortex is responsible for sensations in our muscles and skin. Specifc regions of these two cortices can be mapped to particular regions of the body. Chapter 3 Perception is the set of processes by which we recognize, organize, and make sense of the sensations we receive from environmental stimuli 1. From Sensation to Perception 1.1 Some Basic Concepts of Perception – James Gibson: introduced the concepts of distal (external) object, informational medium, proximal stimulation, and perceptual object: a. distal (far) object: the object in the external world b. informational medium: e.g. sound waves, reflected light, chemical molecules, tactile information c. proximal (near) stimulation: information comes into contact with the appropriate sensory receptors d. perceptual object (i.e., what you see): is created in you; reﬂects the properties of the external world – sensory adaptation: receptor cells adapt to constant stimulation by not fring until there is a change in stimulation → we may stop detecting the presence of a stimulus → constant stimulation of the cells of the retina gives the impression that the image disappears = Ganzfeld-Effect – eyes constantly make tiny rapid movements → creates constant changes in the location of the projected image inside the eye 1.2 Seeing Things That Aren’t There, or Are They? – mental percept = a mental representation of a stimulus that is perceived – minds must take available sensory information and manipulate that information to create mental representations of objects, properties, and spatial relationships within our environments → sensory information and mental perception may differ e.g. optical illusions 1.3 How Does Our Visual System Work? – visible electromagnetic wavelengths are from 380 to 750 nanometers 1. Vision begins when light passes through the protective covering ( cornea = clear, protective dome) of the eye 2. light passes through the pupil, the opening in the center of the iris 3. It continues through the crystalline lens and the vitreous humor (=gel-like substance that makes up the majority of the eye ) 4. the light focuses on the retina where electromagnetic energy is transduced (converted) into neural electrochemical impulses – Vision is most acute in the fovea (a small, thin region of the retina) – The retina contains the photoreceptors: convert light energy into electrochemical energy that is transmitted by neurons to the brain – two kinds of photoreceptors: a. rods (120 million/eye) = long and thin photoreceptors; more highly concentrated in the periphery of the retina than in the foveal region; responsible for night vision and sensitive to light and dark stimuli b. cones (8 million/eye) = short and thick photoreceptors ; allow for the perception of color; more highly concentrated in the foveal region than in the periphery of the retina →both contain photo pigments, chemical substances that react to light and transform physical electromagnetic energy into an electrochemical neural impulse – neurochemical messages travel via the bipolar cells to the ganglion cells → axons of the ganglion collectively form the optic nerve; optic nerves of the eyes join at the base of the brain to form the optic chiasma – ganglion cells from the inward part of the retina cross through the optic chiasma and extend to the opposite hemisphere of the brain; ganglion cells from the outward area of the retina go to the hemisphere on the same side; the lens of each eye inverts the image of the world → the message sent to the brain is upside-down and backward – 90% of the ganglion cells go to the lateral geniculate nucleus of the thalamus and then to the primary visual cortex (V1 or striate cortex) in the occipital lobe – visual cortex contains several processing areas relating to intensity and quality e.g. color, location, depth, pattern, and form 1.4 Pathways to Perceive the What and the Where – pathway = the path the visual information takes from its entering the human perceptual system through the eyes to its being completely processed – two pathways via two fasciculi (fiber bundles): what–where hypothesis: a. dorsal pathway (where pathway): ascends toward the parietal lobe; for processing location and motion information b. ventral pathway (what pathway): descends to the temporal lobe, for processing the color, shape, and identity of visual stimuli what-how hypothesis: two pathways refer not to what things are and to where they are, but rather to what they are and to how they function → What diﬀers between the two pathways is whether the emphasis is on identifying what an object is or, instead, on how we can situate ourselves so as to grasp the object a. what pathway (ventral stream): identifcation of objects b. how pathway (dorsal stream): controls movements in relation to the objects that have been identifed through the what pathway 2. Approaches to Perception: How Do We Make Sense of What We See? 2.1 Bottom-Up Theories = approaches in which perception starts with the stimuli whose appearance you take in through your eye → data-driven (i.e., stimulus-driven) theories – four main theories: direct perception, template theories, feature theories, and recognition- by-components theory a. Direct Perception: Gibson’s Theory of Direct Perception → the information in our sensory receptors, including the sensory context, is all we need to perceive anything = ecological perception → no need for higher cognitive processes, existing beliefs or higher-level inferential thought processes to mediate between sensory experiences and perceptions – use of texture gradients as cues for depth and distance → aid to perceive directly the relative proximity or distance of objects and of parts of objects – Ecological constraints apply not only to initial perceptions but also to the ultimate internal representations (such as concepts) that are formed from those perception – Neuroscientifc evidence: mirror neurons start firing directly after perceiving stimulus, with no time to form hypothesis; separate neural pathways (what pathways) in the lateral occipital area process form, color, and texture in objects b. Template Theories – suggest that our minds store myriad sets of templates – Templates = highly detailed models for patterns we might recognize – We recognize a pattern by comparing it with our set of templates, then choose the exact template that perfectly matches what we observe – = chunk-bcased theorie i.e. theories that suggest that expertise is attained by acquiring chunks of knowledge in long-term memory that can later be accessed for fast recognition – fails to explain some aspects of the perception of letters c. Feature-Matching Theories = we attempt to match features of a pattern to features stored in memory, rather than to match a whole pattern to a template or a prototype Pandemonium Model: metaphorical “demons” with specifc duties receive and analyze the features of a stimulus – four kinds of demons: 1. image demons:receive a retinal image and pass it on to... 2. feature demons: calls out when matches are made between the stimulus and the given feature 3. cognitive demons: shout out possible patterns stored in memory that conform to one or more of the features noticed by the feature demons 4. decision demons: decides on what has been seen, based on which cognitive demon is shouting the most frequently – other feature mathing theories: distinguish global (features that give a form its overall shape) versus local (constitute the small-scale or detailed aspects of a given pattern) features → global precedence eﬀect: participants in a study were slowed down if they had to identify local (small) S’s combining to form a global (big) H instead of identifying local (small) H’s combining to form a global (big) H → local precedence eﬀect: letters are more widely spaced; participants more quickly identify the local features of the individual letters than the global ones, local features interfere with global recognition in cases of contradictory stimuli – neuroscientific evidence for feature-matching: research showed that the visual cortex contains specifc neurons that respond only to a particular kind of stimulus (e.g., a horizontal line), and only if that stimulus fell onto a specifc region of the retina → individual cortical neuron can be mapped to a specifc receptive feld on the retina; show a hierarchical structure in the degree of complexity of the stimuli; neurons that can recognize a complex object are called gnostic units or “grandmother cells” c. Recognition-by-Components (RBC) Theory = we recognize 3-D objects by manipulating simple geometric shapes called geons (for geometrical ions) (Irving Biederman) such as bricks, cylinders, wedges, cones, … → observing the edges and then decomposing the objects into geons – geons are viewpointinvariant – explains how we may recognize general instances of chairs, lamps, and faces, but it does not adequately explain how we recognize particular chairs or particular faces – studies have found neurons in the inferior temporal cortex that are sensitive to viewpoint-invariant properties; other neurons respond primarily to one view of an object and decrease their response gradually the more the object is rotated → unclear if theory is correct 2.2 Top-Down Theories = perception is driven by high-level cognitive processes, existing knowledge, and the prior expectations that inﬂuence perception → constructive approach – constructive perception: the perceiver builds (constructs) a cognitive understanding (perception) of a stimulus; perceiver uses sensory information as the foundation for the structure but also uses other sources of information to build the perception → intelligent perception (higher-order thinking plays an important role) – color constancy: we perceive that the color of an object remains the same despite changes in lighting that alter the hue – during perception, we quickly form and test various hypotheses regarding percepts, based on: what we sense (the sensory data) what we know (knowledge stored in memory) what we can infer (using high-level cognitive processes) – Context eﬀects: the inﬂuences of the surrounding environment on perception – confgural-superiority eﬀect: objects presented in certain confgurations are easier to recognize than the objects presented in isolation, even if the objects in the confgurations are more complex than those in isolation – object-superiority eﬀect: target line that forms a part of a drawing of a 3-D object is identifed more accurately than a target that forms a part of a disconnected 2-D pattern – word-superiority eﬀect: when presented with strings of letters, it is easier to identify a single letter if the string makes sense and forms a word instead of being just a nonsense sequel of letters – central relation between perception and intelligence 2.3 How Do Bottom-Up Theories and Top-Down Theories Go Together? – Extreme versions of both approaches are not entirely plausible – In genera we perceive objects holistically; if we plan to act on them, we perceive them more analytically so that we can act in an effective way (Ganel and Goodale) 3. Perception of Objects and Forms 3.1 Viewer-Centered versus Object-Centered Perception a. viewer-centered: the individual stores the way the object looks to him or her → what matters is the appearance of the object to the viewer b. object-centered: the individual stores a representation of the object, independent of its appearance to the viewer – Recent research suggests that it is more likely we engage in viewer-centered representation than object-centered representation - it has been found that neurons react to changes in view c. landmark-centered: information is characterized by its relation to a well-known or prominent item 3.2 The Perception of Groups—Gestalt Laws – Gestalt approach to form perception: particularly useful for understanding how we perceive groups of objects or even parts of objects to form integral wholes – Kurt Koffka, Wolfgang Köhler and Max Wertheimer – law of Prägnanz: tendency to perceive any given visual array in a way that most simply organizes the diﬀerent elements into a stable and coherent form – other Gestalt principles: figure-ground perception, proximity, similarity, continuity, closure, and symmetry figure-ground: what stands out from, versus what recedes into, the background Symmetry: features appear to have balanced proportions around a central axis or a central point – even children use Gestalt principles, but the principles appear to apply only to humans and not to other primates → only humans misjudge the middle circle in the Ebbinghaus Illusion 3.3 Recognizing Patterns and Faces – two systems for recognizing patterns (Martha Farah): a. feature analysis system: specializes in recognizing parts of objects and in assembling those parts into distinctive wholes b. confgurational system: specializes in recognizing larger confgurations, not analyzing parts of objects or the construction of the objects – second system is most relevant to recognizing faces – both confgurational and feature analysis may help in making diffcult recognitions and discriminations – Face recognition occurs, at least in part, in the fusiform gyrus of the temporal lobe → responds intensely when we look at faces but not when we look at other objects – Face recognition differs from recognition of other complex objects → more difculty in recognizing parts of faces than recognizing whole faces, but recognition of parts of houses works just as well as whole houses – age-related “face positivity” eﬀect: older adults preferred looking at happy faces and looking away from sad or angry faces Neuroscientific findings: – Highly anxious people’s amygdalas always process fear automatically, but less anxious people’s do not – emotion increases activation within the fusiform gyrus when people are processing faces – Patients with autism have impaired emotional recognition → fusiform gyrus is less active than in nonautistic populations. – expert-individuation hypothesis: the fusiform gyrus is activated when one examines items with which one has visual expertise – Prosopagnosia (inability to recognize faces): damage to the confgurational system 4. The Environment Helps You See 4.1 Perceptual Constancies – Perceptual constancy = perception of an object remains the same even when our proximal sensation of the distal object changes – Size constancy = perception that an object maintains the same size despite changes in the size of the proximal stimulus → Jsomething that we largely have to learn, not completely inborn – Muller-Lyer Illusion – Shape constancy = perception that an object maintains the same shape despite changes in the shape of the proximal stimulus; easier with symmetrical objects 4.2 Depth Perception – Depth = the distance from a surface, usually using your own body as a reference surface when speaking in terms of depth perception – Monocular depth cues: can be represented in just two dimensions and observed with just one eye; include include a. texture gradients, b. relative size, c. interposition, d. linear perspective, e. aerial perspective, f. location in the picture plane, and g. motion parallax – Binocular depth cues: based on the receipt of sensory information in three dimensions from both eyes a. binocular disparity: eyes send increasingly disparate (diﬀering) images to brain as objects approach → brain interprets the degree of disparity as an indication of distance b. binocular convergence: eyes increasingly turn inward as objects approach → brain interprets these muscular movements as indications of distance – binocular neurons.: integrate incoming information from both eyes to form information about depth; are found in the visual cortex 5. Deficits in Perception 5.1 Agnosias and Ataxias agnosia: trouble perceiving sensory information, often caused by damage to the border of the temporal and occipital lobes → cannot recognize what the objects are; trouble with the what pathway. – visual-object agnosia: can see all parts of the visual feld, but the objects do not mean anything – simultagnosia: unable to pay attention to more than one object at a time – Prosopagnosia = severely impaired ability to recognize human faces ( optic)ataxia: mpaired ability to use the visual system to guide movement (impaired how pathway) – processing failure in the posterior parietal cortex 5.2 Anomalies in Color Perception – much more common in men than in women; genetically linked – rod monochromacy/achromacy (least common): no color vision at all – dichromacy: only two of the mechanisms for color perception work, and one is malfunctioning → one of three types of color blindness (color-perception deficits) a. red-green, protanopia b. deuteranopia (trouble seeing greens) c. tritanopia (blue-green confusion, yellows disappear) SUMMARY 1. How can we perceive an object, such as a chair, as having a stable form given that the image of the chair on our retina changes as we look at it from different directions? Perceptual experience involves four elements: distal object, informational medium, proximal stimulation, and perceptual object. Proximal stimulation is constantly changing because of the variable nature of the environment and physiological processes designed to overcome sensory adaptation. Perception therefore must address the fundamental question of constancy. Perceptual constancies (e.g., size and shape constancy) result when our perceptions of objects tend to remain constant. Tat is, we see constancies even as the stimuli registered by our senses change. Some perceptual constancies may be governed by what we know about the world. For example, we have expectations regarding how rectilinear structures usually appear. But constancies also are inﬂuenced by invariant relationships among objects in their environmental context. One reason we can perceive 3-D space is the use of binocular depth cues. Two such cues are binocular disparity and binocular convergence. Binocular disparity is based on the fact that each of two eyes receives a slightly diﬀerent image of the same object as it is being viewed. Binocular convergence is based on the degree to which our two eyes must turn inward toward each other as objects get closer to us. We also are aided in perceiving depth by monocular depth cues. These cues include texture gradients, relative size, interposition, linear perspective, aerial perspective, height in the picture plane, and motion parallax. One of the earliest approaches to form and pattern perception is the Gestalt approach to form perception. The Gestalt law of Prägnanz has led to the explication of several principles of form perception. These principles include figure-ground, proximity, similarity, closure, continuity, and symmetry. they characterize how we perceptually group together various objects and parts of objects. 2. What are two fundamental approaches to explaining perception? Perception is the set of processes by which we recognize, organize, and make sense of stimuli in our environment. It may be viewed from either of two basic theoretical approaches: constructive or direct perception. The viewpoint of constructive (or intelligent) perception asserts that the perceiver essentially constructs or builds up the stimulus that is perceived. He or she does so by using prior knowledge, contextual information, and sensory information. In contrast, the viewpoint of direct perception asserts that all the information we need to perceive is in the sensory input (such as from the retina) that we receive. An alternative to both of these approaches integrates features of each. It suggests that perception may be more complex than direct-perception theorists have suggested, yet perception also may involve more efficient use of sensory data than constructive-perception theorists have suggested. Specifcally, a computational approach to perception suggests that our brains compute 3-D perceptual models of the environment based on information from the 2-D sensory receptors in our retinas. Te main bottom-up theoretical approaches to pattern perception include template-matching theories and feature-matching theories. Some support for feature-matching theories comes from neurophysiological studies identifying what are called feature detectors in the brain. It appears that various cortical neurons can be mapped to specifc receptive felds on the retina. Diﬀering cortical neurons respond to diﬀerent features. Examples of such features are line segments or edges in various spatial orientations. Visual perception seems to depend on three levels of complexity in the cortical neurons. Each level of complexity seems to be further removed from the incoming information from the sensory receptors. Another bottom-up approach, the recognition-by-components (RBC) theory, more specifcally delineates a set of features involved in form and pattern perception. Bottom-up approaches explain some aspects of form and pattern perception. Other aspects require approaches that suggest at least some degree of top-down processing of perceptual information. For example, top-down approaches better but incompletely explain such phenomena as context eﬀects, including the object-superiority eﬀect and the word-superiority eﬀect. 3. What happens when people with normal visual sensations cannot perceive visual stimuli? Agnosias, which are usually associated with brain lesions, are defcits of form and pattern perception. they cause aficted people to be insufficiently able to recognize objects that are in their visual felds, despite normal sensory abilities. People who suﬀer from visual-object agnosia can sense all parts of the visual feld. But the objects they see do not mean anything to them. Individuals with simultagnosia are unable to pay attention to more than one object at a time. People with spatial agnosia have severe difculty in comprehending and handling the relationship between their bodies and the spatial confgurations of the world around them. People with prosopagnosia have severe impairment in their ability to recognize human faces, including their own. These deficits lead to the question of whether specifc perceptual processes are modular—specialized for particular tasks. Color blindness is another type of perceptual defcit. Chapter 4 1. The Nature of Attention and Consciousness Attention – Attention = the means by which we actively select and process a limited amount of information from all of the information captured by our senses, our stored memories, and our other cognitive processes → includes conscious and unconscious processes – increases likelihood to react speedily and accurately to interesting stimuli – Consciousness = the feeling of awareness and the content of awareness, some of which may be under the focus of attention → partial overlap with attention – Conscious attention: a. monitor interactions with the environment b. linking past (memories) and our present (sensations) → continuity c. control and plan for future actions four main functions of attention: signal detection and vigilance, search, selective attention, and divided attention 1.1 Attending to Signals over the Short and Long Terms – Signal-detection theory (SDT) = framework to explain how people pick out important stimuli embedded in a wealth of irrelevant, distracting stimuli – trying to detect target stimulus (signal) → four possible outcomes: a. hit (true positive) b. false alarms (fale positive) c. miss (false negative) d. correct rejection (true negative) – Sensitivity = hits minus false alarms – STD in context of attention, perception and memory: a. attention - paying enough attention to perceive objects that are there b. perception - perceiving faint signals that may or may not be beyond perceptual range (e.g. high-pitched tone) c. memory - indicating whether you have or have not been exposed to a stimulus before – Vigilance = ability to attend to a feld of stimulation over a prolonged period, during which the person seeks to detect the appearance of a particular target stimulus → expectations regarding stimulus location strongly aﬀect response efficiency – amygdala and thalamus are involved in vigilance → amygdala: recognition of emotional stimuli 1.2 Search: Actively Looking – search = scan of the environment for particular features – distracters = nontarget stimuli that divert attention away from the target stimulus – two kinds of search: a. feature search: looking for just one feature (e.g., color, shape, or size) that makes search object diﬀerent from all others → number of distracters does not slow down process b. conjunction search: combination of two or more features to find the stimulus → number of targets and distracters aﬀects the difculty – two theories of concjunction search: a. Feature-integration theory (Treisman): two stages in perception of object first stage: perception of features of objects, including color and size; automatic, automatic no need for conscious attention, occurs in feature searches second stage: connecting two or more features with some sort of “mental glue”; requires conscious attention neuropsychological evidence: specifc neural feature detectors = cortical neurons that respond diﬀerentially to visual stimuli of particular orientations b. Similarity Theory: the more similar target and distracters are, the more difficult it is to fnd the target; difficulty also depends on similarity of distracters, but not on number of integrated features – Study on Aging and Visual Search (Madden): Younger adults’ searches were more accurate and faster than the searches of the older adults 1.3 Selective Attention Colin Cherry: – cocktail party problem = process of tracking one conversation while distracted by other conversations – dichotic presentation: separate message to each ear (shadowing = listening to two diﬀerent messages) → participants noticed sensory changes in unattended message (e.g. pitch) but not semantic ones – different theories of Selective Attention Early Filter Model: we filter information right afer we notice it at the sensory level Information is being perceived and stored in sensory memory → s.m. stores information for a split second and then forwards it to a filter → allows only one message to move forward to be processed → message is distinguished by characteristics such as loudness, pitch, or accent → Short-term memory enables response to the message and to store necessary information in long-term memory Selective Filter Model: Messages that are of high importance to a person may break through the flter of selective attention (e.g. hearing one's name) → filter blocks out most information at the sensory level, but some personally important messages are so powerful that they burst through the filtering mechanism Attenuation Model: At least some information about unattended signals is being analyzed (coherent with empirical findings) → attenuating mechanism - instead of blocking out stimuli, the filter (attenuator) merely weakens (attenuates) the strength of all stimuli other than the target stimulus → if unattented message contains important information (e.g., our name), it will be picked up, even though the signal has been weakened by the attenuator Late-Filter Model (Deutsch and Deutsch): stimuli are filtered out only afer they have been analyzed for both their physical properties and their meaning → would allow people to recognize information entering the unattended ear Synthesis of Early Filter and Late-Filter Models (Ulric Neisser): two processes govern attention: a. Preattentive processes – rapid automatic processes that occur in parallel; can be used to notice only physical sensory characteristics of the unattended message, do not discern meaning or relationships – may be linked to feature detection b. Attentive, controlled processes – later processes that are executed serially and consume time and attentional resources, such as working memory; information is processed in much more detail – may be linked to feature integration → problem with explaining the continuum of processes from fully automatic ones to fully controlled ones neural correlates: – When target stimulus occurrs in attended ear the first negative component of ERP is larger than when the target occurrs in the unattended ear (N1 is a negative wave that appears about 90 milliseconds after ttarget stimulus) → result of the enhancement of the target stimulus while other stimuli are suppressed → consistent with flter theories – Similar findings for visual perception (P1) – children of mothers with lower levels of education show reduced eﬀects of selective attention on neural processing 1.4 Divided Attention – can be improved by practice – psychological refractory period (PRP) eﬀect (attentional blink): people fairly easily process physical properties of incoming information while engaged in another speeded task, but when they need to engage in more elaborate processing such as choosing a response or retrieving information from memory, their speed will decline and one or both tasks will show the PRP eﬀect – capacity models of attention: people have a fxed amount of attention that they can choose to allocate according to what the task requires: a. One model suggests that one single pool of attentional resources can be divided freely → likely to simple, similar tasks interfere b. Another model suggests multiple sources of attention are available, one for each modality (e.g., verbal or visual) – use of cell phones appears to be substantially more risky than listening to the radio while driving 1.5 Factors That Inﬂuence Our Ability to Pay Attention – a. Anxiety: Being anxious, either by nature (trait-based anxiety) or by situation (state-based anxiety), places constraints on attention b. Arousal: verall state of arousal aﬀects attention as well → being tired, drowsy, or drugged may limit attention, being excited sometimes enhances attention c. Task difculty: working on a task that is difcult/novel → more attentional resources; difficulty particularly inﬂuences performance during divided attention d. Skills: The more practiced /skilled in performing a task, the more attention is enhanced 1.6 Neuroscience and Attention: A Network Model – Michael Posner: the attentional system in the brain “is neither a property of a single brain area nor of the entire brain” → three subfunctions of attention: a. alerting = being prepared to attend to some incoming event, and maintaining this attention, also getting to this state of preparedness; right frontal and parietal cortexes and locus coeruleus involved, neurotransmitter: norepinephrine; dysfunction: ADHS b. orienting = selection of stimuli to attend to; superior parietal lobe, temporal parietal junction, frontal eye felds, and the superior colliculus involved, neurotransmitter: acetylcholine, dysfunction: autism c. executive attention: processes for monitoring and resolving conﬂicts that arise among internal processes e.g. thoughts, feelings,...; anterior cingulate, lateral ventral, prefrontal cortex and basal ganglia involved, neurotrans.: dopamine, dysfunction: Alzheimer’s disease, borderline personality disorder, and schizophrenia 2. When Our Attention Fails Us 2.1 Attention Deficit Hyperactivity Disorder = difficulties in focusing attention in ways that enables to adapt in optimal ways to the environment – differences in frontal-subcortical cerebellar catecholaminergic circuits and in dopamine regulation – three primary symptoms of ADHD: inattention, hyperactivity and impulsiveness – three main types: (1) hyperactive-impulsive (2) inattentive (3) a combination of hyperactive-impulsive and inattentive behaviour – usually detected in childhood, does not end in adulthood, but may vary in severity – treatment usually includes medication (Ritalin, Metadate, Strattera) and therapy 2.2 Change Blindness and Inattentional Blindness – Change Blindness = inability to detect changes in objects or scenes that are being viewed – Inattentional blindness = inability to see things that are actually there 2.3 Spatial Neglect—One Half of the World Goes Amiss – Spacial neglect (hemineglect) = attentional dysfunction in which participants ignore the half of their visual feld that is contralateral to the hemisphere of the brain that has a lesion – result mainly of unilateral lesions in the parietal and frontal lobes (most often in the right hemisphere) – extinction: when presented with stimuli only to right/left side, perception is often possible, no matter which side the stimulus is on → no major visual-feld defects, but when stimuli are present in both sides of the visual feld → ignorance of the stimuli contralateral to lesion → patients are not able to disengage their attention from the stimulus in the ipsilateral field (the part of the visual feld where the lesion is) in order then to shift their attention to the contralateral visual feld – also problems in representing timeline → indication that similar brain mechanism govern spatial visualization and temporal events 3. Automatic and Controlled Processes in Attention 3.1 Automatic and Controlled Processes automatic processes: performed without conscious awareness; demand little or no eﬀort or even intention; multiple processes may occur at once → parallel processes controlled processes: require conscious control, performed serially (→ serial processes) – alternative view: continuum of processes between fully automatic processes and fully controlled processes – automatization (proceduralization): Controlled processes becoming automatic ones 3.2 How Does Automatization Occur? – Popular view: during practice, implementation of the various steps becomes more efficient → single steps are integrated into single operation which requires few cognitive ressources – alternative theory: instance theory = automatization occurs because we gradually accumulate knowledge about specific responses to specifc stimuli – eﬀects of practice on automatization show a negatively accelerated curve → early practice effects are bigger 3.3 Automatization in Everyday Life – dyslexia: automatization is impaired – Stroop eﬀect: written words interfere with naming the color of the ink – explanations: a. reading is an automatic process for most adults b. different pathways interfere – different variations: a. number Stroop b. directional Stroop c. animal Stroop d. emotional Stroop → similarities: interference of two properties 3.4 Mistakes We Make in Automatic Processes – Types of Mistakes: a. Mistakes = errors in choosing an objective or in specifying a means of achieving it b. Slips = errors in carrying out an intended means for reaching an objective → mistakes involve errors in intentional, controlled processes; slips often involve errors in automatic processes – Slips most likely when a. we must deviate from a routine and automatic processes inappropriately override intentional, controlled processes b. automatic processes are interrupted – likelihood can be decreased by environmental feedback e.g. physical constraints → Norman doors 4. Consciousness 4.1 The Consciousness of Mental Processes – no conscious access to simple mental processes e.g. letter recognition – access to complex mental processes → different views: a. Simon: people have good access to their complex mental processes; based on experiments with protocol analysisof people solving complex problems b. Nisbett & Wilson: access to their complex mental processes is not very good → people think they know how they solve complex problems, but their thoughts are frequently erroneous → only conscious of products of thinking, but not process; minimal control over mental processes 4.2 Preconscious Processing – Preconscious information includes stored memories that we are not using at a given time but that we could summon when needed – Priming = participants are presented with first stimulus (the prime) → break (milliseconds to weeks or months) → participants are presented with second stimulus → participants make a judgment to see whether the presentation of the frst stimulus aﬀected the perception of the second ; explanation: presentation of the first stimulus may activate related concepts in memory that are then more easily accessible – two types: a. positive priming: first stimulus facilitates later recognition b. negative priming: initial stimulus impedes later recognition – priming occurs even when stimulus is presented in a way that does not permit entry into conscious awareness (e.g. presented too briefly) – experiment: “dyad of triads” task → Participants were presented with pairs (dyads) of three-word groups, one with coherent words, one with random, unrelated words, then participants were shown various choices for a fourth word related to one of the triads and asked to identify which of the two triads was coherent and related to a fourth word, and which fourth word linked the coherent triad → participants could often correctly identifiy the coherent triad without finding the relating word → preconscious information – tip-of-the-tongue phenomenon: trying to remember something that is stored in memory but that cannot readily be retrieved → particular preconscious information, although not fully accessible to conscious thinking, is still available to attentional processes – blindsight = traces of visual perceptual ability in blind areas → Some visual processing seems to occur even when participants have no conscious awareness of visual sensations (only for participants with vision impairment due to cortcical lesions) explanation: information from the retina is forwarded to (damaged) visual cortex →part of the visual information bypasses the visual cortex and is sent to other cortical locations → information from these locations is unconsciously accessible SUMMARY 1. Can we actively process information even if we are not aware of doing so? If so, what do we do, and how do we do it? Whereas attention embraces all the information that an individual is manipulating (a portion of the information available from memory, sensation, and other cognitive processes), consciousness includes only the narrower range of information that the individual is aware of manipulating. Attention allows us to use our limited active cognitive resources (e.g., because of the limits of working memory) judiciously, to respond quickly and accurately to interesting stimuli, and to remember salient information. Conscious awareness allows us to monitor our interactions with the environment, to link our past and present experiences and thereby sense a continuous thread of experience, and to control and plan for future actions. We actively can process information at the preconscious level without being aware of doing so. For example, researchers have studied the phenomenon of priming, in which a given stimulus increases the likelihood that a subsequent related (or identical) stimulus will be readily processed (e.g., retrieval from long-term memory). In contrast, in the tip-of-the-tongue phenomenon, another example of preconscious processing, retrieval of desired information from memory does not occur, despite an ability to retrieve related information. Cognitive psychologists also observe distinctions in conscious versus preconscious attention by distinguishing between controlled and automatic processing in task performance. Controlled processes are relatively slow, sequential in nature, intentional (requiring eﬀort), and under conscious control. Automatic processes are relatively fast, parallel in nature, and for the most part outside of conscious awareness. Actually, a continuum of processing appears to exist, from fully automatic to fully controlled processes. 2. What are some of the functions of attention? One main function involved in attention is identifying important objects and events in the environment. Researchers use measures from signal-detection theory to determine an observer’s sensitivity to targets in various tasks. For example, vigilance refers to a person’s ability to attend to a feld of stimulation over a prolonged period, usually with the stimulus to be detected occurring only infrequently. Whereas vigilance involves passively waiting for an event to occur, search involves actively seeking out a stimulus. People use selective attention to track one message and simultaneously to ignore others. Auditory selective attention (such as in the cocktail party problem) may be observed by asking participants to shadow information presented dichotically. Visual selective attention may be observed in tasks involving the Stroop eﬀect. Attentional processes also are involved during divided attention, when people attempt to handle more than one task at once; generally, the simultaneous performance of more than one automatized task is easier to handle than the simultaneous performance of more than one controlled task. With practice, however, individuals appear to be capable of handling more than one controlled task at a time, even engaging in tasks requiring comprehension and decision making 3. What are some theories cognitive psychologists have developed to explain attentional processes? Some theories of attention involve an attentional flter or bottleneck, according to which information is selectively blocked out or attenuated as it passes from one level of processing to the next. Of the bottleneck theories, some suggest that the signal-blocking or signal-attenuating mechanism occurs just afer sensation and before any perceptual processing; others propose a later mechanism, afer at least some perceptual processing has occurred. Attentional-resource theories oﬀer an alternative way of explaining attention; according to these theories, people have a fxed amount of attentional resources (perhaps modulated by sensory modalities) that they allocate according to the perceived task requirements. Resource theories and bottleneck theories actually may be complementary. In addition to these general theories of attention, some task-specifc theories (e.g., feature-integration theory, and similarity theory) have attempted to explain search phenomena in particular. 4. What have cognitive psychologists learned about attention by studying the human brain? Early neuropsychological research led to the discovery of feature detectors, and subsequent work has explored other aspects of feature detection and integration processes that may be involved in visual search. In addition, extensive research on attentional processes in the brain seems to suggest that the attentional system primarily involves two regions of the cortex, as well as the thalamus and some other subcortical structures; the attentional system also governs various specifc processes that occur in many areas of the brain, particularly in the cerebral cortex. Attentional processes may be a result of heightened activation in some areas of the brain, of inhibited activity in other areas of the brain, or perhaps of some combination of activation and inhibition. Studies of responsivity to particular stimuli show that even when an individual is focused on a primary task and is not consciously aware of processing other stimuli, the brain of the individual automatically responds to infrequent, deviant stimuli (e.g., an odd tone). By using various approaches to the study of the brain (e.g., positron emission tomography, event-related potential, lesion studies, and psychopharmacological studies), researcher are gaining insight into diverse aspects of the brain and also are able to use converging operations to begin to explain some of the phenomena they observe. Chapter 5 – Memory = the means by which people retain and draw on their past experiences to use that information in the present (Encoding, Storage, Retrieval): a. encoding: you transform sensory data into a form of mental representation. b. storage: you keep encoded information in memory c. retrieval: you pull out or use information stored in memory 1. Tasks Used for Measuring Memory 1.1 Recall versus Recognition Tasks – Recall = expressive knowledge → you produce a fact, a word, or other item from memory – Recognition = receptive knowledge → responsive to a stimulus – three types of recall: a. Serial recall = recall it the exact order in which they were presented b. Free recall = recall in any order c. Cued recall = shown items in pairs, during recall presented with only one item of each pair → recall each mate – Relearning = the number of trials it takes to learn once again items that were already learned in the past → shorter learning times; true for all ages and also animals – Recognition better than recall (even with extensive training, the best measured recall performance is about 80 items) 1.2 Implicit versus Explicit Memory Tasks Explicit memory: – participants engage in conscious recollection – Explicit memory changes over time → infants and older adults often have relatively poor explicit memory, but implicit memory that is comparable to that of young adult Implicit memory: – participants use information from memory but are not consciously aware that they are doing so – Priming (e.g. word stem completion tasks) = is the facilitation of ability to utilize missing information – Procedural knowledge, tested with: a. rotary pursuit: requires participants to maintain contact between an L-shaped stylus and a small rotating disk → participants are asked to complete the task again, either with the same disk and the same speed or with a new disk or speed → when new disk or speed is used, participants do relatively poorly.; with same disk and speed, participants do as well as before b. mirror tracing: plate with the outline of a shape it is put behind a barrier where it cannot be seen → Beyond barrier is a mirror → participant reaches around the barrier, hand and shape are within view → Participants take a stylus and trace the outline of the shape → difficulties at first, become effective with practive → retention of skill gives way to study procedural knowledge or impact of sleep on procedural kowledge → sleep improves procedural knowledge – Doesn’t change over time like explicit memory does Process-dissociation model (Daniels et.al., 2006; Jacoby, 1991): – Implicit and explicit memory both have a role in virtually every response - Two-process theory: intentional vs. automatic uses of memory 2. Two Contrasting Models of Memory 2.1 The Traditional Model of Memory (Atkinson & Shiffrin) – three memory stores, sensory store, short-term store, long term store – differentiates between stores and memory a. stores = Structure that holds information (hypothetical constructs) b.memory = stored information a. Sensory store (iconic store) = initial repository of much information which eventually enters the short- and long-term stores – Iconic store = discrete visual sensory register that holds information for very short periods in the form of icons = visual images that represent something Sperling's Discovery – Independent variable: whole report vs. partial report + delay of tones a. whole-report procedure: participants report every symbol they have seen b. partial-report procedure (Sperling's innovation): participants need to report only part of what they see → extrapolation from sample to toal knowledge – Dependent variable: number of letters recalled – Results: participants had available roughly 9 of the 12 symbols if they were cued immediately before or immediately after the appearance of the display. However, when they were cued 1 second later, their recall was down to 4 or 5 of the 12 items Partial report advantage at -100,0, +150ms intervals Partial report reduced at 300ms interval Partial report eliminated at 1 second interval – Problems: Participants had to report multiple symbols → may have experienced fading of memory during the report; output-interference = verbally reporting multiple symbols may interfere with reports of iconic memory Subsequent Refinement: – Just one letter must be recalled from two rows of eight letters – Results: 12 out of 16 correct (75%) → 12 items is capacity of sensory memory – Usage of backward visual masking (= mental erasure of a stimulus caused by the placement of one stimulus where another one had appeared previously) at intervals >100ms, and under 250ms -> iconic memory can be erased b. Short-Term Store – Limited capacity -> Miller: 7 +/- 2 chunks (increased by chunking); any delay or interference can cause seven-item capacity to drop to about three items – Limited duration -> ca. 30Sec, unless it is rehearsed to retain it – has some control processes available that regulate the ﬂow of information to and from the long-term store – Information ist stored acoustically rather than visually, but it is also possible to store visual information in short-term memory (shapes, colours,...) – storage seems to depend on numbers of objects rather than numbers of features c. Long-Term Store – Perhaps of infinite capacity and duration (Penfield) → no indication of limit so far – Permastore - Very long-term storage e.g. foreign language or mathematics → Can occur even for information that have been passively learned (street names, etc.) → Separate memory system? 2.2 The Levels-of-Processing Model levels-of-processing (LOP) framework: – Memory varies along continuous dimension in terms of depth of encoding; does not comprise specific number of separate stores – The level at which information is stored depends on how it is encoded → theoretically an infinite number of levels of processing (LOP) → processing as the key to storage; the deeper the level of processing, the higher the probability that an item may be remembered – Three levels of processing in progressive order of depth: a. physical: Visually apparent features b. phonological: Sound combinations associated with the letters (e.g., rhyming) c. semantic: Meaning → can also be applied to nonverbal stimuli, e.g. faces – Self-reference effect: very high levels of recall when asked to relate words meaningfully to the participants by determining whether the words describe them – highest levels of recall occur with words that people consider self-descriptiv – Critique: circular definition - the levels are defined as deeper because the information is retained better, but the information is viewed as being retained better because the levels are deeper paradoxes in retention – rhyming may yield better results than semantic processing → Revision of LOP: – Sequence of the levels of encoding may not be as important → the better the match between the type of elaboration of the encoding and the type of task required for retrieval, the better the retrieval results – Two kinds of strategies for elaboration the encoding: a. Within-item elaboration = elaboration of encoding of the particular item in terms of its characteristics b. Between-item elaboration = elaboration of encoding by relating each item's features to features of items already in memory 2.3 An Integrative Model: Working Memory (Baddeley) – most widely used and accepted model – more dynamic view, whereby working memory serves not only to hold information but also to process that information – Working memory holds only the most recently activated, or conscious, portion of longterm memory, and it moves these activated elements into and out of brief, temporary memory storage The Components of Working Memory a. Central executive: coordinates attentional activities and governs responses → decides how to divide attention between two or more tasks that need to be done at the same time, or how to switch attention back and forth between multiple tasks; involved in higher-order reasoning and comprehension and is central to human intelligence b. Visuospatial sketchpad: holds visual images; contains spatial and visual information Logie: Visual cache (passive) and Inner scribe (active) c. Phonological loop: inner speech for verbal comprehension and for acoustic rehearsal two components: I. Phonological storage (passive): holds information in memory II. Subvocal rehearsal (active): puts information in memory by nonverbally rehearsing; can also verbally label images → articulatory suppression: subvocal rehearsal is inhibited, the new information is not stored word length effect: we can remember fewer longer words compared with shorter words because it takes us longer to rehearse and produce the longer word c. Episodic buffer: binds information from the visuospatial sketchpad and the phonological loop as well as from longterm memory into a unitary episodic representation; integrates information from different parts of working memory → allows us to solve problems and reevaluate previous experiences with more recent knowledge d. Subsidiary "slave systems": perform other cognitive or perceptual tasks – working memory capacity is a good predictor of academic success – One view (Cowan): working memory is embedded within long-term memory – recent study: wm is limited resource that is distributed between the diﬀerent items that need to be held in memory Neuroscience and Working Memory – Areas involved in visuospatial sketchpad: Prefrontal cortex, Supplementary motor, premotor area, Posterior parietal area, Superior parietal area, Occipital lobe; fusiform gyrus (fusiform face area [FFA]) is activated to a greater extent when a person looks at faces as opposed to other objects such as house – Areas involved in phonological loop: Left hemisphere of the lateral frontal and inferior parietal lobes as well as the temporal lobe; Broca's area, Brodmanns areas and Insula – Areas involved in central executive: little is known, activation mostly in the frontal lobes – Areas involved in episodic buffer: frontal lobes and portions of the temporal lobes, including the left hippocampus – brain regions that are involved in the perception of particular stimuli are also important for the maintenance of those stimuli in working memory; Working memory does not consist of one brain region but rather is represented across a variety of brain regions Measuring Working Memory a. Retention delay task: old or new? b. Temporally ordered working memory load task: old or new? c. Temporal order task: which is the most recent? d. N-back task: find and repeat n-back e. Temporally ordered working memory load task: reproduce in correct order f. Temporally ordered working memory load task: reproduce final items in correct order → allows for the examination of how much information can be manipulated in memory; often paired with secondary task 2.4 Multiple Memory Systems – Distinction of two memory systems (Endel Tulving): a. Semantic memory: general knowledge (facts) b. Episodic memory: personal experiences – Evidence for semantic vs. episodic memory: Lesions in the frontal lobe appear to affect recollection regarding when a stimulus was presented, but they do not affect recall or recognition memory that a particular stimulus was presented. Some people have only trouble to recall facts, other people have only trouble to recall personal events – It is not clear that semantic and episodic memory are two distinct systems → Boundary is fuzzy, Methodological problems with some of the supportive evidence – Perhaps episodic memory is a specialized form of semantic memory – neuroscientifc model called HERA (hemispheric encoding/retrieval asymmetry): there is greater activation in the left prefrontal hemisphere for tasks requiring retrieval from semantic memory and more activation in the right prefrontal hemisphere for episodic retrieval tasks → model proposes that semantic and episodic memories must be distinct because they draw on separate areas of the brain 2.5 A Connectionist Perspective – Connectionist models arguethat our brain handles many operations and processes at once → parallel-processing model of working memory Connectionist parallel distributed processing (PDP) model: – based on a network of interconnected neuronlike computational units ( nodes) → key to knowledge representation lies in the connections among nodes (elements) stored in memory – Fits nicely with the notion of working memory as comprising the activated portion of long- term memory – Activation spreads through nodes within the network – explanation for Priming: Prime = node that activates a connected node → Priming effect = resulting activation of the node – Integrates several contemporary notions about memory: – Working memory comprises the activated portion of long-term memory and operates through at least some amount of parallel processing – Spreading activation involves the simultaneous activation of multiple links among nodes within the network – Contemporary cognitive-psychological conceptions of working memory, network models of memory, spreading activation, priming, and parallel processing mutually enhance and support one another – Connectionist models effectively explain priming effects, skill learning, and several other phenomena of skill learning, but have failed to provide clear predictions and explanations of recall and recognition memory that occurs following a single episode or a single exposure to semantic information → some psychologists believe that complex behaviour displays a degree of top-down orderliness and purposefulness that connectionist models, which are bottom-up, cannot incorporate 3. Exceptional Memory and Neuropsychology 3.1 Outstanding Memory: Mnemonists – Mnemonist = someone who demonstrates extraordinarily keen memory ability, usually based on using special techniques for memory enhancement → Can be learned to some extent – Synesthesia = experience of sensations in a sensory modality diﬀerent from the sense that has been physically stimulated → Can interfere with ability to follow a conversation → Hard to understand abstract concepts – Hypermnesia = process of producing retrieval of memories that would seem to have been forgotten → Achieved by trying many and diverse retrieval cues to unearth a memory; Risk: individuals may create a new memory, believing it is an old one 3.2 Deficient Memory – Amnesia = Severe loss of explicit memory – different kinds: a. Retrograde amnesia = inability to recall events prior to a dramatic event; light form can be caused by concussion b. Anterograde amnesia = inability to recall events that occur after a traumatic event c. Infantile amnesia = inability to recall events that happens in very early childhood – Amnesia and the Explicit-Implicit Memory Distinction: → Explicit memory is impaired, implicit memory is not impaired → Declarative knowledge is impaired, procedural knowledge is not impaired Amnesia and Neuropsychology – Dissociations: Normal individuals show the presence of a particular function, but people with specific lesions on the brain show the absence of that particular function; This absence occurs despite the presence of normal functions in other areas – Double dissociations: People with different kinds of neuropathological conditions show opposite patterns of deficits; Can be observed if a lesion in brain structure 1 leads to impairment in memory function A but not in memory function B ; and a lesion in brain structure 2 leads to impairment in memory function B but not in memory function A → Offer strong support for the notion that particular structures of the brain play particular vital roles in memory → Support distinctions between explicit and implicit memory Alzheimer's Disease – is a disease of older adults that causes dementia as well as progressive memory loss – Leads to atrophy of the brain (especially in hippocampus and frontal and temporal regions) – Formation of plaques (protein deposits outside neurons) and tangles (pairs of filaments that become twisted around each other in cell bodies and dendrites) – Diagnosed when memory is impaired and when there is at least one other area of dysfunction in the domains of language, motor, attention, executive function, personality, or object recognition – Symptoms are of gradual onset; Progression is continuous and irreversible, but can be slowed – Incidence increases exponentially with age – Early-onset Alzheimer's: linked to genetic mutation; people with this mutation always develop this disease – Earliest signs typically include impairment of episodic memory, alter semantic memory also begins to fade; no difference between emotionally charged information and non- emotionally charged information – Most forms of implicit memory are spared until near the end of its course – Ends in death SUMMARY 1. What are some of the tasks used for studying memory, and what do various tasks indicate about the structure of memory? Among the many tasks used by cognitive psychologists, some of the main ones have been tasks assessing explicit recall of information (e.g., free recall, serial recall, and cued recall) and tasks assessing explicit recognition of information. By comparing memory performance on these explicit tasks with performance on implicit tasks (e.g., word-completion tasks), cognitive psychologists have found evidence of diﬀering memory systems or processes governing each type of task (e.g., as shown in studies of amnesics). 2. What has been the prevailing traditional model for the structure of memory? Memory is the means by which we draw on our knowledge of the past to use this knowledge in the present. According to one model, memory is conceived as involving three stores: A sensory store is capable of holding relatively limited amounts of information for very brief periods; a short-term store is capable of holding small amounts of information for somewhat longer periods; and a longterm store is capable of storing large amounts of information virtually indefnitely. Within the sensory store, the iconic store refers to visual sensory memory. 3. What are some of the main alternative models for the structure of memory? An alternative model uses the concept of working memory, usually defined as being part of long-term memory and also comprising short-term memory. From this perspective, working memory holds only the most recently activated portion of long-term memory. It moves these activated elements into and out of short-term memory A second model is the levels-of-processing framework, which hypothesizes distinctions in memory ability based on the degree to which items are elaborated during encoding. A third model is the multiple memory systems model, which posits not only a distinction between procedural memory and declarative (semantic) memory but also a distinction between semantic and episodic memory. In addition, psychologists have proposed other models for the structure of memory. they include a parallel-distributed processing (PDP; connectionist) model.thePDP model incorporates the notions of working memory, semantic memory networks, spreading activation, priming, and parallel processing of information. Finally, many psychologists call for a complete change in the conceptualization of memory, focusing on memory functioning in the real world. Tis call leads to a shif in memory metaphors from the traditional storehouse to the more modern correspondence metaphor. 4. What have psychologists learned about the structure of memory by studying exceptional memory and the physiology of the brain? Among other fndings, studies of mnemonists have shown the value of imagery in memory for concrete information. they also have demonstrated the importance of fnding or forming meaningful connections among items to be remembered.themain forms of amnesia are anterograde amnesia, retrograde amnesia, and infantile amnesia.thelast form of amnesia is qua

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