PS260 Lecture Notes.pdf

PS260: Introduction to Cognitive Psychology Lecture #1 September 5: Course Intro Course description: Overview of cognitive psychology and illustrates some main theories, results and methods. Cognition is the processing of information, acquisition and use...

PS260: Introduction to Cognitive Psychology Lecture #1 September 5: Course Intro Course description: Overview of cognitive psychology and illustrates some main theories, results and methods. Cognition is the processing of information, acquisition and use of knowledge Main topics addressed: - Visual perception - Attention - Memory structures - Memory processes - Language processing and comprehension - Problem solving - Decision making - Intelligence 3 Bonus quizzes→ each worth 1% (possible 3%) - Why we’ve moved away from old psychologists and their theories and toward cognition - Cannot study cognition without looking at neuroscience behind it - Cannot encode info without paying attention, cannot remember info if it is not encoded Midterms: - 50 minutes, 45 question written in person on lockdown browser Lecture #2 September 10: Cognitive Psych Experiment: Depth Processing - Picture - Eel - Wheel - Sweater - Hammer - Elephant - Car - Steak - Tree - Referee - Pie - Computer Group 1: count number of E’s in each words→ shallow processing, not thinking very hard about it, lesser mental activity Ie. Read tiger, think one Read baboon, think zero Group 2: think of something related to the word→ deeper processing, thinking harder, more mental activity Ie. Read tiger, think lion Read baboon, think monkey Common properties of Cognitive Psychology: Representation: the knowledge we possess in memory Static structure→ almost never changing (early thinking) Dynamic structure→ always changing (modern thinking) Process: an operation on an internal or external stimulus Creating new memories Manipulating new memories Updating and reinterpreting Roots of Cognitive Psychology Plato: - Interested in representation and proposed that memory is like a wax block - Imprint something on a wax block and it should remain there forever - “Imagine, then, for the sake of argument, that our minds contain a block of wax, which in this or that individual may be larger or smaller, and composed of wax that is comparatively pure or muddy, and harder in some, softer in others, and sometimes of just the right consistency. Whenever we wish to remember something we see or hear or conceive in our own minds, we hold this wax under the perceptions or ideas and imprint them on it as we might stamp the impression of a seal ring. Whatever is so imprinted we remember and know so long as the image remains; whatever is rubbed out or has not succeeded in leaving an impression we have forgotten and do not know.” Aristotle:  ○ Doctrine Association Mental life explained in terms of two basic components 1. Ideas (elements) 2. Associations (links between elements) ○ 3 Laws of Associations 1. Contiguity: same time or space (private proctoring) 2. Similarity: alike conceptually (apples, oranges) 3. Contrast: opposites (left and right, hot and cold) Franciscus Donders (1868) ○ First to measure “thinking time” Measured time between a stimulus and different types of responses people had to make 1. People pressed a key as quickly as they could when they felt a touch on either foot (simple reaction time) 2. Sometimes they were instructed to only press key when a specific foot is touched (choice reaction time) ○ Decision time= choice time - simple time Introspection- Wilhelm Wundt/ Edward Titchener ○ Studied conscious mental events (ie. feeling, thoughts, perceptions, recollections) ○ Introspection with minimum interpretation (look within to observe and record content of mental lives ○ Problems: 1. Unconscious thought? 2. Testability- no objective data Introspection Experimental subjective objective Individual thoughts/perspectives Group data averaged non-statistical statistical ○ Structuralism: find the simplest mental elements and the laws governing the ways they can be combined Ebbinghaus (1885) ○ Created method for estimating forgetting ○ Showed that memory processes were quantifiable by measuring behaviour Method of savings: Memorized lists of nonsense syllables (eg. dah, duh, luh, etc) Tested memory for lists at different time intervals (20 mins, 1hr, 9hrs, 1 day, 2 days, 6 days, 31 days)  ○ After periods of time he could not recall any syllables, but it took less time to relearn a previous list than it originally took (something was saved in memory) Savings= original learning time- relearning time William James (late 1800s) ○ Made distinction between primary and secondary memory Primary memory= short term memory Secondary memory= long term memory ○ Functionalism: define the properties of the mind in terms of the function that it serves Examine relationship between adaptation and psychological phenomena 20th Century: Behaviourism (Anti-cognitive approach) ○ Watson/Skinner Behaviour is objective and observable No role for consciousness, introspection, “mind” Uncovered principles of how behaviour changed in response to stimuli, such as rewards and punishments Ie. operant and classical conditioning ○ Problems: 1. Behaviour comes from understanding, not from stimulus a. Mentalistic notions needed to explain why and how we perform various tasks 2. Equating learning with performance a. Memory is not simply the performance of a learned act (there is more to memory than learning) 3. Complex learning- learning? (fundamental to cognition, sets us apart from primates) From introspection and behaviourism, experimental psychologists learned that: Introspective methods for studying mental events are not scientific We need to study mental events in order to understand behaviour Need objective method for examining mental processes Cognitive Revolution 1. Transcendental Method Immanuel Kant Works backwards from observations to determine cause What is the best explanation based on available facts Allows for firm conclusions on invisible events Cognitive psychologists study mental events, but do so indirectly: - measure/manipulate stimuli and responses - Develop hypotheses about mental events - Design experiments to test alternative possibilities for results 2. Communication engineering advancing during WW2  - Offered analogies for interpreting cognitive processes - Channels have View of information as physical changes led to concept for experimental analysis of the mind - Encoding - Decoding - Information processing - Communication channels - Channel capacity - Noise 3. Computer as Metaphor (1950) - Computer analogy provided framework for studying the mind - Information storage, decision making, problem solving, - Psychological data explained in terms of “buffers”, “gates”, and “central processors” - Can hypothesize a series of information-processing steps - Allowed for testing of steps, led to important new discoveries about intellectual functioning in the 1960s and 1970s Broadbent (1958) Filter Model of Selective Attention: Waugh and Norman (1965) Information Processing Model  4. Linguistic Theory Behaviourist approach to language ○ Associative Chain Theory: a sentence consists of a chain of associations between individual words Language acquisition and use explained by reinforcement and conditioning Family provides environment where proper language is spoken and errors are corrected “Verbal Behaviour” B.F. Skinner Chomsky’s Review of Skinner’s Verbal Behaviour ○ Productivity of Language: People produce and understand an infinite number of sentences that are different from those previously produced or heard Cannot be reduced to stimulus response chains ○ Poverty of Stimulus: Information in language samples given to children cannot fully account for the richness and complexity of children’s language ○ Intuitive Knowledge of Grammar Colourless green ideas sleep furiously Furiously sleep ideas green colourless Words with little to no associations can still be syntactically acceptable ○ Ie. nouns, verbs, and adjectives are where they would normally go in a sentence ○ Notion of Linguistic Units (word) George picked up the baby George picked the baby up Discontinuous units show long range dependencies among words in sentences ○ “Up” is displaced, but it is still understood it is being used in relation to “picked” By mid 1960s cognitive psychology established itself as the dominant field of psychology, leading to the term Cognitive Revolution Lecture #3 September 12: Neural Basis of Cognition 1. Main structures of the Brain 2. Capgras Syndrome 3. Brain Lateralization 4. Primary Motor and Sensory Projection Areas 5. Association Areas and Lesions Principle Structures of the Brain 3-4 lbs Trillion neurons ○ Each neuron is associated with at least tens of thousands of other neurons Massive neuronetwork 1. Hindbrain Located directly on top of spinal cord Controls crucial life functions ○ Eg. heartbeat, breathing, alertness (initiating sleep), balance *Cerebellum: movement, spatial reasoning, discriminating sounds integrating sensory input 2. Midbrain Sits above hindbrain Coordinates eye movement Includes auditory ○ Inferior colliculi (auditory): relay auditory information to forebrain for processing ○ Superior Colliculi (visual): receive input from eyes, reflexive movement of eyes, tracking visual objects 3. Forebrain Largest structure Contains cortex ○ 3mm thick but comprises 80% of brain ○ Convolutions produce massive surface area ○ Deep fissures divide brain into different sections Fissures and Lobes of Forebrain 1. Longitudinal Fissure: separates left and right hemispheres 2. Central Fissure: separates the frontal and parietal lobes from each other 3. Lateral Fissure: separates the frontal and temporal lobes from each other Subcortical structures of forebrain Thalamus: integration center and “relay station” for most sensory information going to cortex Hypothalamus: motivative behaviours; eating, drinking, sexual activity Limbic System Hippocampus: long-term and spatial memory Mamillary Body: long term memory Amygdala: emotion and evaluation of stimuli Capgras Syndrome (amygdala damage) Recognise loved ones Think they are imposters, cannot feel an emotional connection to them People with capgras may think they were kidnapped May even see slight “defects” ○ Results from a conflict ○ Perceptual cognition intact ←conflict→ no emotion = lack of familiarity Can even go as far as homes and locations Separate pathway that goes from the auditory complex to amygdala, compared to the one that goes from the visual cortex to amygdala ○ When seeing mother “not my mother, looks like her but it’s not” but when hearing her on the phone “it is my mother” ○ Visual information/response is dominant David had no galvanic response to pictures of his parents Lack of emotional response leads David to believe and override his own intellect that his parents aren’t really his parents Cannot form any new emotional attachments Pairs of Structures and Brain Lateralization Cortical and subcortical structures come in pairs Roughly the same size and shape Same pattern of connection to brain area *can be large differences in function ○ Eg. language– dominated by left hemisphere ○ Spatial reasoning– dominated by right hemisphere Lateralization Commissures: bundles of fibers that carry information back and forth between hemispheres ○ Largest is the corpus callosum Split brain patients: severing of the corpus callosum ○ Treatment of epilepsy ○ Limits left and right hemisphere communication But can see what hemisphere is responsible for what Cortical organization is contralateral ○ Left side of the body or perceptual world has more representation on the right side of the brain, and vice versa Primary Motor & Sensory Projection Areas Primary Motor Projection Area Located at rear if frontal lobe Contains nerve cells that send signals ○ Stimulation to one hemisphere leads to moven=ment on the opposite side of the body ○ Areas form maps of body– specific positions in cortex correspond to specific body parts ○ More precise movement=more corresponding space 1. Touch Front of parietal lobe Contralateral processing of touch More cortical space devoted to parts of body most sensitive to touch Parts of body near to each other represented in nearby areas of the brain 2. Auditory Superior temporal love Contralateral processing of sound Different frequencies of sound have own brain areas Adjacent sites responsive to adjacent frequencies Increase in cortical space to speech frequencies 3. Visual Occipital lobe Contralateral processing of visual space Regions of visual space (visual field) have own cortical representation Adjacent areas of space have adjacent brain sites Most cortical space devoted to fovea Federmeier and Kutas (1999) “They wanted to make the hotel look like a tropical resort. So along the driveway they planted rows of palms/pines/tulips” - Palms: expected exemplar - Pines: within category violation (expect a type of tree, not the one expected) - Tulips: between category violation (not expected, also not from the same category) Procedure: last word was presented to right or left hemisphere, earlier words were presented centrally Visual half-brain technique ○ N400 brain wave Expected word produces small N400 Non-expected words produce larger N400 ○ Used to study somatic processing Left Hemisphere: differentiating between the words that don’t fit (pine and tulip) ○ Tulip has a more negative N400 because it is not what was expected and it is not of the same category as palm ○ Predictive hemisphere Right Hemisphere: does not differentiate between the words that don’t fit ○ “Wait and see” hemisphere Association Errors Association areas only 75% of Cortex Associate ideas and sensations for complex thoughts/behaviour  Initiate and coordinate skilled movements Lesions in Association Areas and Cognitive deficits 1. Apraxias a. Lesions in frontal lobes b. Disturbances in initiation or organization of voluntary action 2. Agnosias a. Lesions in occipital cortex and parietal lobe b. Disruption in ability to recognize in familiar objects c. Often involve only one modality 3. Neglect Syndrome a. Lesions to parietal lobe b. Person neglects half of visual world i. Eat food from half of plate, shave half of face ii. Overtime may get the attention deficit back 4. Aphasia a. Disruption of language capacities from damage to left frontal and temporal lobes b. Damage to motor projection areas leads to difficulties in producing speech (Broca’s area) c. Damage to auditory projection area leads to difficulties in comprehending speech (Wernicke's area) 5. Damage to Prefrontal area of Frontal Lobes a. Problems of planning and implementing strategies b. Problems inhibiting own behaviour (social rules) c. Prone to confusion (did something happen or not) Lecture #4 September 17: Cognitive Neuroscience Techniques Neurons Dendrites: detect incoming signals Cell body: nucleus and cellular machinery Axon: Transmit signals to other neurons, covered in myelin sheath (fatty substance) Axon terminal: communicate with synapses of dendrites on other neurons Synapse: neurons have firing thresolds and fire when enough ions flowinto cell and thresholds are met ○ Postsynaptic response varies according to three factors 1. How much neurotransmitter presynaptic membrane release 2. Sensitivity of postsynaptioc cell to neurotransmitters 3. post synaptic membranes can receive input from multiple neuron “All or none law” ○ Once threshold is met, magnitude of signal produced by axonisalways the same Neuron can fire frequently and for longer periods of time Cognititve Newuroscience Techniques Computerized Axial Tomography (CT/CAT Scan) ○ Computer compares signals from multiple x-ray detectors to pinpoint source of each signal ○ Computer recontructs 3D map of brain ○ Important for telling us where structures are, and if the structures are normal MAgnetic Resonance Imaginf (MRI) ○ Magnetoic field passes through tissue, causes alignment of nuclei of atoms ○ Radio waves disrupt spins of atoms ○ Atoms realign with magnetic field ○ Energy released by atoms are used to create a detailed image Functional MAgnetic Imaging (fMRI) ○ Same principles as MRI, but measures oxygen content in blood ○ Provides excellent method for tracking blood flow/brain activity ○ Best spatial resolution available ○ Limited in temporal resolution Doesnt work on a very fine time scale, needs an extended period of time to be accurate (>1-2s) Transcranial Magnetic Stimulation (TMS) ○ Strong magnetic pulses are applied to specific regions of scalp ○ Temporarily disrupts brain processes in cortex underneath scalp ○ Allows examination of the function of brain areas with “normal” brains Event-related Brain Potentional Methodology (ERP) ○ Electrical currents are generated by axons firing ○ When large assemblies of neurons fire together in a similar region in the brain, the electrical currents are detectable at the surface of the scalp ○ Relative to some area chosen as a reference site (usually mastoid) the electrical current is always more positive or negative  ○Brain waves have a series of positive and negative peaks, some of these are determined by cognitive processing ○ Average across multiple trials of the same type to get the pattern to come out Positron Emission Tomography (PET Scan) ○ Individuals are injected with a radioactive substance ○ Photon detectors track radioactive substance in blood, provides measure of glucose levels ○ Important for learning about brain function Cheaper than fMRI, but not as widely used due to diminished resolution in comparison to fMRI Chapter 3: Visual System 1. Modality in which humans acquire a lot of knowledge 2. Much is known about neural wiring of visual system Photoreceptors Rods Cones Lower Sensitivty High Sensitivity Lower acuity High Acuity Colour-blind Colour-Sensitive Peripheryof retina In the fovea, center Optic Nerve Photoreceptors stimulate bipolar cells, with stimulate ganglion cells Ganglion cells collect information from retina and then gather to form optic nerve Optic nerve carries information to difference sites in the brain ○ Thalamus (lateral, geniculate nucleus) ○ Occipital Cortex (V1, primary visual projection area) Optic nerve is not just a passive carrier of information Process of lateral inhibition occurs in optic nerve; crucial for edge enhancement Single-Cell Recording Center-surrounded Cells→ “dot detectors” ○ Stimulus in center leads to faster firing rates ○ Stimulus in surrounding area leads to slower firing rates Orientation Specific Cells (Edge Detectors) ○ Fire most frequently for stimuli with specific orientations ○ Will fire less as a result iof the degree that orientation is different Movement detectors  ○ Fire strongly when stimuli move across their receptive fields in specific directions Angle Detectors ○ Fire to angles ofa particular size Parallel Processing in Visual System “Divide and conquer” ○ Different cells specialized for analysis of visual importance ○ Analysis is performed simultaneously Main Advantages: ○ Speed→ no waiting for other processes to be completed first ○ Mutual influence among systems → systems “negotiate” solutions that fit both systems WHat and Where Systems 1. Pathway from occipital cortex to temporal lobe is known as “WHAT” system a. Crucial for object identification, damage leads to agnosia 2. Pathway from occipital cortex to parietal lobe is known as “WHERE” system a. Crucial for object location, damage leads to difficulty reaching Binding Problem: The task of reuniting the carious elements of a scene Elements are dea;lt with by different systems in different parts of the brain ○ Spatial Position: Brian systems keep track of the locations of objects Reassembling pieces can be doine by overlaying maps of elements (colours are where, motion is where) ○ Neural Synchrony: visual areas processing features for the same object fire in a synchronous rhythm with eachother ○ Attention: Narrows range of information we receive Neural firing become synchronized for atteneded stimuli Diminishes confusion about what elements go together Overloading attention causes conjunction errors Ie. blue “H” and red “T”, perceived as red “H” and a blue “T” Brain Plasticity Changes in the function and structure of neural pathways that are caused by the change sin bahviour, environment, and from brain injury Recovery from brain injury is best if: ○ Injury occurs