- Light hits cornea (focuses light) to pupil (determined amt of light) to lens (more focus) til light hits retina (transduction) to optic nerve to brain for perception

Retina and Transduction

- Retina has photoreceptors (rods and cones) at back of eye converting light to neural impulses

- Photopigments change shape due to glutamate

- Signal sent to adj bipolar cells (sensory neurons) and ganglion cells

- Then signal travels to brain through optic nerve (blind spot)

Receptors

- Rods: 120 million cells, high sensitivity and low acuity, in periphery, black and white vision

- Cone: 5 million cells, low sensitivity and high acuity, in fovea, colour vision

Theories of Colour Vision

- Trichromatic theory: 3 kinds of cones

- L (red, long waves), M(green, med waves), S (blue, short waves)

- But it’s a range and overlap

- People with fewer cones of a type than they should, producing colour blindness

- Opponent Process theory: something preventing the simultaneous processing of colour combos

- Bipolar cells combine inputs from diff cone types

- Ganglion cells respond in antagonistic way to opposing pairs of wavelengths (activated by red, inhibited by green)

- Explains afterimages, colour perception by brain

Visual Perception and the Brain 02/04/25

- Info from L visual field goes to R side of brain, no matter which eyes see it

- Optic nerve connects with thalamus, travelling to V1 (primary visual cortex in occipital lobe)

- Retina à v1à dorsal or ventral (to temporal) visual streams

- Dorsal: locate objects spatially and perform simple actions, no need for meaningfulness

- Ventral: recognize objects, conscious perception of details, attach meaning to what we see

- Blindsight: cortically blind but still responsive to visual stimuli, can still navigate objects around them

- Visual info can go to the superior colliculus without V1, automatic route

Hollow Face Mask Illusion

- Illusion of protrusion of face

- People unconscious go to the right location even if they are consciously fool

- Peoples motor systems are accurate

Case of Dr. P (Mistaken of Wife for a Hat)

- Example of difficulty of facial identification but normal other senses

- He couldn’t perceive or recognize it as a problem

- Diagnosis with visual agnosia (impairment in visual presented objects recognition)

- Prosopagnosia: cants visual recognition

- Hypothesized tumor or degeneration of visual association cortex

Perceptual Organization

Gestalt Psychology

- Grouping of visual information to form perceptions

- Proximity: groups of items together

- Similarity: pattern recognition like alternating colours

- Continuity: mind wants to see continuous image

- Closure: mind wants to fill in images

- Connectedness: physical connection

Depth Perception

- Able to see objects in 3D although image strikes retina is 2D

- Ex. Visual Cliff on babies

- Early skill

Monocular Cues: focus on one eye

- Relative size: objs farther away project smaller retinal images, based on objective placement

- Elevation: items that are higher in visual are perceived as further, BUT flipped at horizon (sunset paintings)

- Interposition: object obscures other in visual

- Linear Perspective: parallel lines and spaces between them, further lines look larger

- Relative motion: fixated objs move backwards, behind object moves forwards and movement speed (car ride)

Binocular Cue: Retinal Disparity

- Diff bet objects projected on two eyes: obj further away from line of focus appear at inc diff locations on retinas

- Perception room: appears diff height at different parts of room

Psychology of Learning 02/06/25

Defining Learning

- Physical and chemical changes in brain

- Chemical aspects: neurotransmission

- Physical aspects: neurons

How to Learn

- Classical conditioning, operant conditioning

- Mental rep

- Watching others

Associative Learning

- Classical: two stimuli occurrence, involuntary

- Operant: voluntary relationship behaviour and consequence

Classical Condition

- Found by Ivan Pavlov: Pavlov’s Dogs

- Buzzer sound linking to stimulus of receiving food

- Automatic unlearned response(dogs’ drooling)

- 1. Before conditioning: automatic unlearned response

- 2. During cond: neutal stimulation with actual stim, unconditional response

- 3. After cond: neutal stimulation (conditioned stim) without actual stim, conditional response

- CR and UR are usually same behaviour BUT not always

Key Parts of Classical Condition

- Intensity: strength of association depends on vividness of stimuli, sometimes repeats of experiments aren’t needed

- Generalization: stimuli like CS elicit CR

- Discrimination: learning not respond to certain stim

- Extinction & Spontaneous recovery: CS doesn’t cause CR when presented alone

Applications of Classical Condition

- Emotional response: learning to fear stimuli, fear conditioning (ex. Little albert, learning to fear animals), some are having preparedness to fear stimuli

- Taste Aversions: acquired dislike of food/drink paired with an illness

- Drug Tolerance: dec reaction occurring with repeated use of drug, compensatory response, sometimes causing overdose

Classical Cond and Advertising

- Attractive person as conditional stim, advertised product is neutral stim

- Conditions a person to like the product

Operant Condition

- Law of effect: from Thorndike behaviour is a function of consequence

- ABCs: Antecedent, Behaviour, Consequence

- Skinner’s research found reinforcement and punishment

Reinforcement vs. Punishment

- Reinforcement: consequences increase likelihood behaviour reoccurs

- Note positive and negative examples

- Punishment: consequences decrease likelihood behaviour reoccurs

02/11/25

Shaping

- Encouraging a new behaviour through reinforcing successive approx. (reward systems, ex. gradual change)

Reinforcement Schedules

- Often and under circumstances individual receives reinforcement (or punishment)

- Continuous vs. Partial reinforcement schedules

- Ex. recieving a treat for cleaning up toys

- 4 elements: fixed vs variable and ratio vs interval

- Fixed, reinforce after a specific number

- Variable, reinforce randomnly

- Ratio: reinforce based on event occurrences

- Interval: based on amount of time

- Most common: variable ratio, no prediction of time, and unpredictable occurrences

Associative Learning and Behaviourism

- Focus on observable behaviour- no mental processes

- Learning as passive response to environmental stimuli

- Not genetics based

Cognitive Revolution: significance of believes and thoughts

- Insight learning: Koehler: puzzles for chimps

- Developed insight: learning is not just condition based

- Latent learning: Tolman, rats learn mazes without reward

- Superstitious Conditioning: false association to mind but no actual connection

Obs Learning

- “aka Social learning” learning by observing and imitating others

- Ex. rats learn by smelling eachothers breath, to find near food

- Ex. Bobo Doll Study, adult beat the doll, and children observed adult model and mimicked behaviour (actions and saying), reinforcement and punishment

- Based on mirror neurons: fires when animal performs action and animal observes someone else performed same action (monkey see, monkey do)

Cognitive Memory

- Process of maintaining info over time

- 3 stages: 1. Encoding to input, 2. Storage to saved information, 3. Retrieval to output (like a computer)

Multistore Model of Memory

- Sensory memory: not long storage, high capacity and detailed (perfect copy of memory)

- Short-term memory: slightly longer than sensory, more concepts but less details

- Long-term memory: longest storage, way less detail, quite complex

- Everything goes to sensory but we memories we attend go to short-term memory

- Some of that is consolidated to long term memory

Sensory Memory

- Memory goes to all sensory sys

- Iconic: visual form of sensory memo (less than 1 sec)

- Echoic: auditory form of sensory memo (up to 4 sec)

- Ex. Sperling’s Memory Task (1960): 12 letters shown for 1/20^th of a second, whole report: recalled about 3-4 letters but partial report: mainly accurate

- Ex. 2 Changed Blindness: Focused attention, don’t notice change, the blank screen makes it harder to retain memory of image when looking at the second image

Short-Term Memory

- Info we pay attention to committed to short-term memory

- Fraction of info in environment

- Aka “working memory” , but has limited working capacity

- Magic Number 7: holding 5-9 pieces of info in mind (chunking of phone numbers)

- Retain through rehearsal: repeating info in working memory

- Either maintenance (same info in short term) , elaborative (making info meaningful for oneself)

- Ex. (1 stick of butter, a loaf of bread, and a jug of milk)

Long-Term Memory

- Unlimited capacity and duration

- Explicit: declarative (conscious recall), goes into episodic (experiences) , semantic (knowledge)

- Implicit: not stated (unconscious recall), procedural (actions like riding a bike), conditioning, priming