COGNITIVEPRELIMREVIEWER2024.pdf

Cognitive psychology is the scientific investigation of human cognition, that is, all our mental abilities – perceiving, learning, remembering, thinking, reasoning, and understanding. It is closely related to the highly interdisciplinary cognitive science and influenced by artif...

Cognitive psychology is the scientific investigation of human cognition, that is, all our mental abilities – perceiving, learning, remembering, thinking, reasoning, and understanding. It is closely related to the highly interdisciplinary cognitive science and influenced by artificial intelligence, computer science, philosophy, anthropology, linguistics, biology, physics, and neuroscience. The term “cognition” stems from the Latin word “cognoscere” or "to know". Fundamentally, cognitive psychology studies how people acquire and apply knowledge or information. Imagine all of your thoughts as if they were physical entities, swirling rapidly inside your mind. How is it possible that the brain is able to move from one thought to the next in an organized, orderly fashion? The brain is endlessly perceiving, processing, planning, organizing, and remembering—it is always active. Yet, you don’t notice most of your brain’s activity as you move throughout your daily routine. This is only one facet of the complex processes involved in cognition. Simply put, cognition is thinking, and it encompasses the processes associated with perception, knowledge, problem solving, judgment, language, and memory. Scientists who study cognition are searching for ways to understand how we integrate, organize, and utilize our conscious cognitive experiences without being aware of all of the unconscious work that our brains are doing (for example, Kahneman, 2011). Cognitive psychology is the field of psychology dedicated to examining how people think. It attempts to explain how and why we think the way we do by studying the interactions among human thinking, emotion, creativity, language, and problem solving, in addition to other cognitive processes. Cognitive psychologists strive to determine and measure different types of intelligence, why some people are better at problem solving than others, and how emotional intelligence affects success in the workplace, among countless other topics. They also sometimes focus on how we organize thoughts and information gathered from our environments into meaningful categories of thought. History of Cognitive Psychology Maybe you’ve heard the phrase I think , therefore I am, or perhaps even the Latin version: Cogito ergo sum. This simple expression is one of enormous philosophical importance, because it is about the act of thinking. Thought has been of fascination to humans for many centuries, with questions like What is thinking? and How do people think? and Why do people think? troubling and intriguing many philosophers, psychologists, scientists, and others. The word “cognition” is the closest scientific synonym for thinking. It comes from the same root as the Latin word cogito, which is one of the forms of the verb “to know.” Cognition is the set of all mental abilities and processes related to knowledge, including attention, memory, judgment, reasoning, problem solving, decision making, and a host of other vital processes. Human cognition takes place at both conscious and unconscious levels. It can be concrete or abstract. It is intuitive, meaning that nobody has to learn or be taught how to think. It just happens as part of being human. Cognitive processes use existing knowledge but are capable of generating new knowledge through logic and inference. People have been studying knowledge in various ways for centuries. Some of the most important figures in the study of cognition are: Aristotle (384–322 BCE) The study of human cognition began over two thousand years ago. The Greek philosopher Aristotle was interested in many fields, including the inner workings of the mind and how they affect the human experience. He also placed great importance on ensuring that his studies and ideas were based on empirical evidence (scientific information that is gathered through observation and careful experimentation). Descartes (1596–1650) René Descartes was a seventeenth-century philosopher who coined the famous phrase I think, therefore I am (albeit in French). The simple meaning of this phrase is that the act of thinking proves that a thinker exists. Descartes came up with this idea when trying to prove whether anyone could truly know anything despite the fact that our senses sometimes deceive us. As he explains, “We cannot doubt of our existence while we doubt.” Wilhelm Wundt (1832–1920) Wilhelm Wundt is considered one of the founding figures of modern psychology; in fact, he was the first person to call himself a psychologist. Wundt believed that scientific psychology should focus on introspection, or analysis of the contents of one’s own mind and experience. Though today Wundt’s methods are recognized as being subjective and unreliable, he is one of the important figures in the study of cognition because of his examination of human thought processes. Cognition, Psychology, and Cognitive Science The term “cognition” covers a wide swath of processes, everything from memory to attention. These processes can be analyzed through the lenses of many different fields. Because of the number of disciplines that study cognition to some degree, the term can have different meanings in different contexts. For example, in psychology, “cognition” usually refers to processing of neural information; in social psychology the term “social cognition” refers to attitudes and group attributes. These numerous  approaches to the analysis of cognition are synthesized in the relatively new field of cognitive science, the interdisciplinary study of mental processes and functions. Cognition, Psychology, and Cognitive Science The term “cognition” covers a wide swath of processes, everything from memory to attention. These processes can be analyzed through the lenses of many different fields. Because of the number of disciplines that study cognition to some degree, the term can have different meanings in different contexts. For example, in psychology, “cognition” usually refers to processing of neural information; in social psychology the term “social cognition” refers to attitudes and group attributes. These numerous approaches to the analysis of cognition are synthesized in the relatively new field of cognitive science, the interdisciplinary study of mental processes and functions. Concepts and Prototypes The human nervous system is capable of handling endless streams of information. The senses serve as the interface between the mind and the external environment, receiving stimuli and translating it into nervous impulses that are transmitted to the brain. The brain then processes this information and uses the relevant pieces to create thoughts, which can then be expressed through language or stored in memory for future use. To make this process more complex, the brain does not gather information from external environments only. When thoughts are formed, the brain also pulls information from emotions and memories. Emotion and memory are powerful influences on both our thoughts and behaviors. In order to organize this staggering amount of information, the brain has developed a file cabinet of sorts in the mind. The different files stored in the file cabinet are called concepts. Concepts are categories or groupings of linguistic information, images, ideas, or memories, such as life experiences. Concepts are, in many ways, big ideas that are generated by observing details, and categorizing and combining these details into cognitive structures. You use concepts to see the relationships among the different elements of your experiences and to keep the information in your mind organized and accessible. Another technique used by your brain to organize information is the identification of prototypes for the concepts you have developed. A prototype is the best example or representation of a concept. For example, for the category of civil disobedience, your prototype could be Mohandas Gandhi served as a nonviolent force for independence for India while simultaneously demanding that Buddhist, Hindu, Muslim, and Christian leaders—both Indian and British— collaborate peacefully. Although he was not always successful in preventing violence around him, his life provides a steadfast example of the civil disobedience prototype (Constitutional Rights Foundation, 2013). Just as concepts can be abstract or concrete, we can make a distinction between concepts that are functions of our direct experience with the world and those that are more artificial in nature. Natural and Artificial Concepts In psychology, concepts can be divided into two categories, natural and artificial. Natural concepts are created “naturally” through your experiences and can be developed from either direct or indirect experiences. An artificial concept, on the other hand, is a concept that is defined by a specific set of characteristics. Various properties of geometric shapes, like squares and triangles, serve as useful examples of artificial concepts. A triangle always has three angles and three sides. A square always has four equal sides and four right angles. Mathematical formulas, like the equation for area (length × width) are artificial concepts defined by specific sets of characteristics that are always the same. Artificial concepts can enhance the understanding of a topic by building on one another. Schemata A schema is a mental construct consisting of a cluster or collection of related concepts (Bartlett, 1932). There are many different types of schemata, and they all have one thing in common: schemata are a method of organizing information that allows the brain to work more efficiently. When a schema is activated, the brain makes immediate assumptions about the person or object being observed. There are several types of schemata. 1. An object schema is perhaps the most basic type of cognitive schema. It holds information about objects – chairs, dogs, cars, tables, and so on. (example: Learning the difference between car and bus.) 2. A person schema holds information about people. A child’s first person schema might be about their parents. (example: Learning about other people’s personalities, roles and preferences.) 3. A role schema holds information about the social roles and positions of people in society. A role schema makes assumptions about how individuals in certain roles will behave (example: Learned gender roles)  4. A person’s self schema refers to how they perceive themself. Parents and teachers spend a lot of time trying to help a young person positive a positive self-schema, or what we might call a positive sense of self. (example: Learning about personal attributes) 5. An event schema is a schema about events. An event schema, also known as a cognitive script, is a set of behaviors that can feel like a routine. (example: Differentiating holidays) From Sensation to Perception How do we perceive the world around us? Perception- the set of processes by which we recognize, organize and make sense of the sensations we receive from environmental stimuli. James Gibson Distal- object in the external world Informational medium-the pattern of event which are happening MODALITY DISTAL INFORMATIONAL PROXIMAL PERCEPTUAL OBJECT MEDIUM STIMULATION OBJECT Vision/Sight Mommy’s Reflected light( Photon Mommy’s face face visible absorption in electromagnetic the rod and waves) cone cells of the retina. Audition/Sound A falling Sound waves by Sound wave A falling tree tree tree’s fall conduction to basilar membrane. Olfaction/Smell Bacon Molecules Molecular Bacon being released by frying absorption in fried bacon the olfactory cells Gustation/Taste Ice cream Molecules of the Molecular Ice cream ice cream contact with taste buds Tactile/Touch Computer Mechanical Stimulation of Computer keys keyboard pressure & receptor cells vibration and within the surface of skin dermis Proximal stimulation-event when information comes into contact with appropriate sensory receptors. Perceptual object-is the object that reflects the properties of the external world Perception occurs when the informational medium carries information about a distal object to a person. When the person’s sense receptors pick up on the information, proximal stimulation occurs, which results in the person’s perceiving the object. Perception occurs when the informational medium carries information about a distal object to a person. When the person’s sense receptors pick up on the information, proximal stimulation occurs, which results in the person’s perceiving the object. Where do we draw the line between sensation, perception and cognition? These processes is part of a continuum. Information flows the system. Different processes address different questions. Questions of sensation focus on the qualities of stimulation. Questions of perception deal with identity, form, pattern and movement. Questions of cognition occurs as this information is used to serve further goals. Seeing things that aren’t there, or are they? Percept- a mental representation of a stimulus that is perceived. Sometimes, we perceive what is not there. Other times, we do not perceive what is there. The existence of perceptual illusions suggest that what we sense (in our sensory organs) is not necessarily what we perceive (in our minds). Our minds must be taking the available sensory information somehow to create mental representations of objects, properties and spatial relationships within our environment. The Duck and Rabbit Illusion: Ambiguous Images and Mid-level Vision This image first appeared in 1892 and has been puzzling and amusing people ever since. The duck-or- rabbit conundrum operates on the principles of how we perceive ambiguous images and the processes of mid- level vision. Mid-level vision is the point at which our brains group visual information based on its ability to find edges in the image. However, in the case of ambiguous images, these edges are not clear, and we become capable of perceiving two contrary depictions within the same image. For this reason, we are able to see either a rabbit or a duck, depending on which depiction we choose to focus on. Approaches to Perception Top-Down vs. Bottom-Up (Conceptually-driven vs. Data-driven processing) While our sensory receptors are constantly collecting information from the environment, it is ultimately how we interpret that information that affects how we interact with the world. Perception refers to the way sensory information is organized, interpreted, and consciously experienced. Perception involves both bottom-up and top-down processing. Bottom-up processing refers to the fact that perceptions are built from sensory input. On the other hand, top-down processing is how we interpret those sensations is influenced by our available knowledge, our experiences, and our thoughts. Bottom-Up Theory vs. Top-Down Theory What's the Difference? Bottom-Up Theory suggests that perception begins with the individual elements of a stimulus, which are then combined to form a complete perception. This theory emphasizes the importance of sensory input in shaping our perceptions. In contrast, Top-Down Theory proposes that perception is guided by higher-level cognitive processes, such as expectations, beliefs, and prior knowledge. This theory suggests that our perceptions are influenced by our mental frameworks and interpretations of the world. Attribute Bottom-Up Theory Top-Down Theory Starts with specific details and Starts with a general understanding and Initiation builds up to a larger breaks it down into specific details understanding Focuses on sensory input and Relies on pre-existing knowledge and Processing perception expectations  Control Driven by external stimuli Driven by internal cognitive processes While Bottom- Up Adaptable to new information Less adaptable to new information and Theory Flexibility focuses and changes changes on the role of sensory information, Top-Down Theory highlights the impact of cognitive processes on perception. Bottom-Up Theories Direct perception (aka Ecological perception)- the information in our sensory receptors, including our sensory context is all we need to perceive anything. We do not need higher cognitive processes to mediate between our sensory experiences and our perceptions. Template Theories- suggests that we have stored in our minds myriad sets of templates. We recognize a pattern by comparing it with our set of templates. It suggest that expertise is attained by acquiring chunks of knowledge in long-term memory that can later be accessed for fast recognition. Templates-highly detailed models for patterns we potentially might recognize. 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. Local Precedence Effect Local features constitute the small-scale or detailed aspects of a given pattern When letters are more widely spaced, we are more quickly to identify the local features of the individual letters than the global ones and the local features interfere with the global recognition in cases of contradictory stimuli. Global Precedence Effect Global features that give a form its overall shape. When the local letters were positioned close together, we could identify stimuli at the global level more quickly than at the local level. Experiments have shown that global information dominates over local information. Top-Down vs. Bottom-Up Top-Down vs. Bottom-Up (Conceptually-driven vs. Data-driven processing) While our sensory receptors are constantly collecting information from the environment, it is ultimately how we interpret that information that affects how we interact with the world. Perception refers to the way sensory information is organized, interpreted, and consciously experienced. Perception involves both bottom-up and top-down processing. Bottom-up processing refers to the fact that perceptions are built from sensory input. On the other hand, top-down processing is how we interpret those sensations is influenced by our available knowledge, our experiences, and our thoughts  Seen alone, your brain engages in bottom-up processing. There are two thick vertical lines and three thin horizontal lines. There is no context to give it a specific meaning, so there is no top-down processing involved. Surrounded by sequential letters, your brain expects the shape to be a letter and to complete the sequence. In that context, you perceive the lines to form the shape of the letter “B.” Surrounded by numbers, the same shape now looks like the number “13.” When given a context, your perception is driven by your cognitive expectations. Now you are processing the shape in a top-down fashion. One way to think of this concept is that sensation is a physical process, whereas perception is psychological. For example, upon walking into a kitchen and smelling the scent of spaghetti, the sensation is the scent receptors detecting the odor of spaghetti , but the perception may be “Mmm, this smells like the spaghetti Mom used to cook when the family gathered for holidays.” Although our perceptions are built from sensations, not all sensations result in perception. In fact, we often don’t perceive stimuli that remain relatively constant over prolonged periods of time. This is known as sensory adaptation. Imagine entering a classroom with an old analog clock. Upon first entering the room, you can hear the ticking of the clock; as you begin to engage in conversation with classmates or listen to your professor greet the class, you are no longer aware of the ticking. The clock is still ticking, and that information is still affecting sensory receptors of the auditory system. The fact that you no longer perceive the sound demonstrates sensory adaptation and shows that while closely associated, sensation and perception are different. Multisensory Perception Although it has been traditional to study the various senses independently, most of the time, perception operates in the context of information supplied by multiple sensory modalities at the same time. For example, imagine if you witnessed a car collision. You could describe the stimulus generated by this event by considering each of the senses independently; that is, as a set of unimodal stimuli. Your eyes would be stimulated with patterns of light energy bouncing off the cars involved. Your ears would be stimulated with patterns of acoustic energy emanating from the collision. Your nose might even be stimulated by the smell of burning rubber or gasoline. However, all of this information would be relevant to the same thing: your perception of the car collision. Indeed, unless someone was to explicitly ask you to describe your perception in unimodal terms, you would most likely experience the event as a unified bundle of sensations from multiple senses. In other words, your perception would be multimodal. The question is whether the various sources of information involved in this multimodal stimulus are processed separately by the perceptual system or not. For the last few decades, perceptual research has pointed to the importance of multimodal perception: the effects on the perception of events and objects in the world that are observed when there is information from more than one sensory modality. Most of this research indicates that, at some point in perceptual processing, information from the various sensory modalities is integrated. In other words, the information is combined and treated as a unitary representation of the world. subliminal perception The idea of subliminal perception - that stimuli presented below the threshold for awareness can influence thoughts, feelings, or actions – is a fascinating and kind of creepy one. Can messages you are unaware of, embedded in movies or ads or the music playing in the grocery store, really influence what you buy? Many such claims of the power of subliminal perception have been made. One of the most famous came from a market researcher who claimed that the message “Eat Popcorn” briefly flashed throughout a movie increased popcorn sales by more than 50% although he later admitted that the study was made up (Merikle, 2000). Psychologists have worked hard to investigate whether this is a valid phenomenon. Studying subliminal perception is more difficult than it might seem, because of the difficulty establishing what the threshold for consciousness is or of even determining what type of thresholds important; for example, Cheesman and Merikle (1984, 1986) make an important distinction  between objective and subjective thresholds. The bottom line is that there is some evidence that individuals can be influenced by stimuli they are not aware of, but how complex stimuli can be or the extent to which unconscious material can affect behavior is not settled. Synesthesia Synesthesia is a condition in which a sensory stimulus presented in one area evokes a sensation in a different area. In the 19th century Francis Galton observed that a certain proportion of the general population who were otherwise normal had a hereditary condition he dubbed "synesthesia"; a sensory stimulus presented through one modality spontaneously evoked a sensation experienced in an unrelated modality. For example, an individual may experience a specific color for every given note (“C sharp is red”) or printed number or letter- is tinged with a specific hue (e.g. 5 is indigo and 7 is green). The specificity of the colors remains stable over time within any given individual but the same note or letter doesn’t necessarily evoke the same color in different people. Synesthesia used to be regarded as a rare condition but recent estimates suggest that it affects 4% of the population. The most common of which appears to be letter sounds associated with color. Most individuals report having had the experience as far back in childhood as they can remember. As Galton himself noted, the condition tends to run in families and recent work suggests a genetic basis. Visual perception deficits Visual agnosia is a condition that disrupts your brain’s ability to process and understand what you see with your eyes. There are several different forms of visual agnosia, with a wide range of effects on your ability to see the world around you. Types: ❑ Akinetopsia. You can recognize objects but can’t recognize that they’re moving. ❑ Alexia. You can’t recognize words you see. That means you can see the words but can’t make sense of or read them. You can still write and speak without any problem. ❑ Achromatopsia. Also known as color agnosia, this is where a person can see colors and tell them apart, but they can’t identify the color. ❑ Form agnosia. You can see the parts of an object but can’t recognize the object itself. An example of this is identifying the wheels, seat and handlebars of a bicycle when you look at each part, but not recognizing them as part of the whole bicycle. ❑ Prosopagnosia is a condition where you struggle to recognize faces or can’t interpret facial expressions and cues. It usually happens because of brain damage, but some people have it at birth. ATTENTION AND CONSCIOUSNESS Attention- the means by which we actively process a limited amount of information from the enormous amount of information available through our senses, our stored memories and our other cognitive processes. Attention includes both conscious and unconscious processes. In many cases, conscious processes are relatively easy to study. Unconscious processes are harder to study because you are not conscious of them. Attention allows us to use our limited mental resources judiciously. By dimming the lights on many stimuli from outside (sensations) and inside (thoughts and memories), we can highlight the stimuli that interest us. This heightened focus increases the likelihood that we can respond speedily and accurately to interesting stimuli. Consciousness- includes both the feeling of awareness and the content of awareness, some of which may be under the focus of attention. *Conscious attention serves three purposes in playing a causal role for cognition. 1. It helps in monitoring our interactions with the environment. Through such monitoring, we maintain our awareness of how well we are adapting to the situation in which we find ourselves. 2. It assists us in linking our past (memories) and our present (sensations) to give us a sense of continuity of experience. Such continuity may even serve as the basis for personal identity. 3. It helps us in controlling and planning for our future actions. We can do so based on the information from monitoring and from the links between past memories and present sensations. Four Main Functions of Attention: Signal detection and vigilance: We try to detect the appearance of a particular stimulus. (observing) Search: We try to find a signal amidst distracters. (looking for a thing in a pile) Selective attention; We choose to attend to some stimuli and ignore others. (conversation in a party) Divided attention: We prudently allocate our available attentional resources to coordinate our performance of more than one task at a time. (cooking and phone conversation) Signal Detection Theory: Finding Important stimuli in a Crowd Signal detection theory- is a framework to explain how people pick out the few important stimuli when they are embedded in a wealth of irrelevant, distracting stimuli. This theory was one of the first theories to suggest an interaction between the physical sensation of a stimuli and cognitive processes such as decision-making. SIGNAL DETECTION MATRIX Signal Example Present Hit or “true positives” The lifeguard correctly identifies the presence of Correctly identifying the somebody drowning. presence of a target. Absent False alarms or ‘false Lifeguard thinks positives’ somebody is drowning who actually isn’t. Incorrectly identifying the presence of a target that is actually absent. Present Miss or “false negatives” Lifeguard does not see the drowning person. Failure to observe the presence of a target. Absent Correct rejections or “true Nobody is drowning and negatives” lifeguard knows nobody is in trouble. Correctly identifies the absence of a target. Vigilance- a person’s ability to attend to a field of stimulation over a prolonged period, during which the person seeks to detect the appearance of a particular stimulus of interest. *When being vigilant, the individual watchfully waits to detect a signal stimulus that may appear at an unknown time. Typically, vigilance is needed in settings where a given stimulus occurs only rarely but requires immediate attention as soon as it does occur. Search: Actively looking Search- refers to a scan of the environment for particular features- actively looking for something when you are not sure where it will appear. Distracters- non-target stimuli that divert our attention away from the target stimulus. *The number of targets and distracters affect the difficulty of the task. THEORIES ABOUT SEARCH PROCESSES DISPLAY SIZE EFFECT Display size – the number of items in a given visual array. (It does not refer to the size of the items or even the size of the field on which the array is displayed). The display size effect is the degree to which the number of items in the display hinders (slows down) the search process. LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLTL LL LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLLL L LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLLL LL LLLLLLLLLLLLLLLLLLLLLLLLL LL L L L L L L L L LL L LLL L L L L LL L L LLL L LL LL L L LL L L LL L L L T L LL L LLLLLLLLLL L LL LL FEATURE SEARCH FEATURE SEARCH-scanning the environment for an item with a distinct feature like color or shape. LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL LLLLLLLLLLLLLLLLLLLLLLLOLLLLLLLLLLL LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL Featural Singletons- items with distinctive features that stand out in the display. * When featural singletons are targets, they seem to grab our attention. OOOOOOOOOOOOOOO OOOOOOOOOOOOOT O OOOOOOOOOOOOOOO OOOOOOOOOOOOOOO OOOOOOOOOOOOOOO OOOO OOOOOOOOOO OOOOOOOOOOOOOOO OOOOOOOOOOOOOOO When featural singletons are targets, they seem to grab our attention. Unfortunately, any featural singletons grab our attention. This includes featural singletons that are distracters that can distract us from finding the target. In Panel D, the T is a featural singleton. But the presence of the black-filled circle probably slowed you down in your search. SIMILARITY THEORY: This theory states that as the similarity between the target and distracter stimuli increases, so does the difficulty in detecting the target stimuli.  Targets that are highly similar to distracters are relatively hard to detect. Targets that are high disparate from distracters are relatively easy to detect. GUIDED SEARCH THEORY: The Guided Search theory suggest that all searches involve two stages: first is the parallel stage: the individual simultaneously activates a mental representation of all the potential targets. The second stage, the serial stage, the individual sequentially evaluates each of the activated elements, according to the degree of activation. Then, the person chooses the true targets from the activated elements. The parallel stage will activate a mental map that contains all the features of the target (circle, black). Thus, black circles, white circles and black squares will be activated. During the serial stage, you will evaluate the black circle, which was highly activated. But then you will evaluate the black squares and the white circles, which were less highly activated. You then will dismiss them as distracters. This effect, now known as the Stroop effect, was first reported in the classic article “Studies of Interference in Serial Verbal Reactions” published in the Journal of Experimental Psychology in 1935. Since then, this phenomena has become one of the most well known in the history of psychology. If Stroop has a test, then what is the actual effect you ask? Well, the Stroop effect is an example of the interesting case where the brain’s reaction time actually slows down when it has to deal with conflicting information. This delayed reaction time is happening because of a processing delay that is caused by competing functions in your brain. This effect is named after John Ridley Stroop who published a paper back in 1935 but the effect had been studied abroad before Stoop’s publishing’s. SELECTIVE ATTENTION Selective attention is the process of focusing on a particular object in the environment for a certain period of time. Attention is a limited resource, so selective attention allows us to tune out unimportant details and focus on what matters. Selective attention is the ability to select certain stimuli in the environment to process, while ignoring distracting information. One way to get an intuitive sense of how attention works is to consider situations in which attention is used. A party provides an excellent example for our purposes. Many people may be milling around, there is a dazzling variety of colors and sounds and smells, the buzz of many conversations is striking. There are so many conversations going on; how is it possible to select just one and follow it? You don’t have to be looking at the person talking; you may be listening with great interest to some gossip while pretending not to hear. However, once you are engaged in conversation with someone, you quickly become aware that you cannot also listen to other conversations at the same time. You also are probably not aware of how tight your shoes feel or of the smell of a nearby flower arrangement. On the other hand, if someone behind you mentions your name, you typically notice it immediately and may start attending to that (much more interesting) conversation. This situation highlights an interesting set of observations. We have an amazing ability to select and track one voice, visual object, etc., even when a million things are competing for our attention, but at  the same time, we seem to be limited in how much we can attend to at one time, which in turn suggests that attention is crucial in selecting what is important. How does it all work? Donald Broadbent and Dichotic Listening Donald E. Broadbent has been praised for his outstanding contributions to the field of psychology since the 1950s, most notably in the area of attention. In fact, despite the undeniable role that attention plays in almost all psychological processes, research in this area was neglected by psychologists for the first half of the twentieth century (Massaro, 1996). During that time, behaviorists ignored the role of attention in human behavior. Behaviorism was characterized by a stimulus-response approach, emphasizing the association between a stimulus and a response, but without identifying the cognitive operations that lead to that response (Reed, 2000). Subsequently, in the mid-1950s, a growing number of psychologists became interested in the information-processing approach as opposed to the stimulus response approach. It was Broadbent’s elaboration of the idea of the human organism as an information-processing system that lead to a systematic study of attention, and more generally, to the interrelation of scientific theory and practical application in the study of psychology. Dichotic Listening Experiments In 1952, Broadbent published his first report in a series of experiments that involved a dichotic listening paradigm. In that report, he was concerned with a person’s ability to answer one of two messages that were delivered at the same time, but one of which was irrelevant. Treisman’s Attenuation Model Treisman suggested that selection starts at the physical or perceptual level, but that the unattended information is not blocked completely, it is just weakened or attenuated. As a result, highly meaningful or pertinent information in the unattended ear will get through the filter for further processing at the level of meaning. Late selection model Late selection or response selection model proposed by Deutsch and Deutsch (1963) suggests that all information in the unattended ear is processed on the basis of meaning, not just the selected or highly pertinent information. However, only the information that is relevant for the task response gets into conscious awareness. This model is consistent with ideas of subliminal perception; in other words, that you don’t have to be aware of or attending a message for it to be fully processed for meaning. Information-Processing and the Filter Model of Attention Cognitive psychology is often called human information processing, which reflects the approach taken by many cognitive psychologists in studying cognition. The stage approach, with the acquisition, storage, retrieval, and use of information in a number of separate stages, was influenced by the computer metaphor and the way people enter, store, and retrieve data from a computer (Reed, 2000). The stages in an information-processing model are: Sensory Store: brief storage for information in its original sensory form Filter: part of attention in which some perceptual information is blocked outand not recognized, while other information is attended to and recognized Pattern Recognition: stage in which a stimulus is recognized Selection: stage that determines what information a person will try to remember Short-Term Memory: memory with limited capacity, that lasts for about 20-30 seconds without attending to its content Long-Term Memory: memory that has no capacity limit and lasts from minutes to a lifetime Divided Attention and Multitasking What is divided attention? Divided attention could be defined as our brain's ability to attend to two different stimuli at the same time, and respond to the multiple demands of your surroundings. Divided attention is a type of simultaneous attention that allows us to process different information sources and successfully carry out multiple tasks at a time. This cognitive skills is very important, as it allows us to be more efficient in our day-to-day lives. MULTITASKING- the performance of more than one task at the same time. Our ability to attend to multiple stimuli and do various tasks at a time does have its limits. When you divide your attention, the efficiency with which you do these actions is decreased, and you will almost certainly perform poorly. Interference is the term used to describe when a person has a hard time attending to two stimuli at a time. We see interference when the brain is only able to process a certain amount of information. However, cognitive training can help improve divided attention, and as a consequence, the ability to do more than one activity at a time. Unless a task is fully automated, some researchers suggest that “multi-tasking” doesn’t really exist; you are just rapidly switching your attention back and forth between tasks. Disorders or pathologies associated with divided attention Divided attention may be altered in a number of different disorders, whether it be due to problems with divided attention itself, or problems with other attentional sub-processes. For someone with poor divided attention, any interference may alter the task that they are doing simultaneously. Divided attention will likely be affected in any disorder that alters attention processes. If a patient suffers from a contralateral heminegligence (inability to attend to the visual field opposite the injury), hypoprosexia (distractability), hyperprosexia (intense concentration on a single stimuli), or aprosexia (inability to concentrate), it will be difficult, or nearly impossible, for the patient to do tasks that require divided attention.