cpsych

2 stages of perception

sensation perception

sensation:

conversion of physical properties of the world or body into a code

transduction:

converting stimuli into neural code

perception:

processing and interpretation of sensory info into useful info for behaiovural decisions

neural code:

frequencies of action potentials

behavioural decisions:

choice made based on interpretation

Exteroception:

measurement (sensation) and interpretation (perception) of external environmental stimulation

Interception:

senses that measure properties in our bodies

3 types of interception

1. proprioception:

2. nociception:

3. equilibrioception:

proprioception:

sense of where out limbs are in space

nociception:

sense of pain due to body damage

equilibrioception:

sense of balance

4 classes of sensory receptors in the body

1. chemoreceptors:

2. mechanoreceptors:

3. thermoreceptors:

4. photoreceptors:

chemoreceptors:

receptors that to chemicals in their local environment

mechanoreceptors:

receptors stimed by physical force or pressure

thermoreceptors:

receptors stimed by heat and cold

photoreceptors:

receptors that respond to light

3 steps for all perceptual modalities

1. transduction of physical energy into a neural code by the senses

2. transmission to the brain through subcortical and cortical structures

3. processing in the cortex to generate behaviours

pupil:

a hold in the iris that expands and contracts to take in or restrict light

iris:

circular ring of coloured muscle at the front of the eye ball

retina:

layers of neurons

photorecpetors:

final layer of light sensitive neurons

2 types of photoreceptors

1. Rods

2. Cones

rods:

reduced resolution, good at night

cones:

high resolution, good in sunlight, for colour

optic nerve:

bundle of axons that pass from the retina to the brain

90% of visual info is sent to...?

the thalamus

how many cortical regions for visual processing

30

Spare code:

algorithm that needs a small number of hidden nodes to rep a stim

Agnosias:

difficulty perceiving a stimulus but not another

2 types of agnosia

1. prosopagnosia:

2. semantic agnosia:

prosopagnosia:

difficulty recognizing INDIVIDUAL faces

Affected fusiform face area FFA

semantic agnosia:

difficulty recognizing every day objects

lateral occipital cortex LOC

visual dorsal stream:

upward, stops at parietal

• Where stream

• Perception

visual ventral stream:

downward, stops at temporal lobe

• What stream

• Action

auditory dorsal stream:

sound localization

auditory ventral stream:

sound identification

pinna:

outer folded ear cartilage for transmitting the sound to the ear canal

ear canal:

tube that amplifies frequencies transmitted to the eardrum

Ear drum:

passes sound into the ossicles

ossicles:

tiny bones that determine freq of sound going to the chochlea

cochlea:

coiled bone thats filled w/ fluid

Basilar membrane:

strip of tissue tin hair cells, mechanoreceptors, that move in vibration w/ fluid in the cochlea

Tonotopic map:

responds to freq decrease as the coil progresses inward

Crest:

top

Trough:

bottom

Wavelength:

distance between two crests

• high freq - Shorter

• Low freq - Long, slow waves

Amplitude:

Hight between crest and trough

1. high amplitude - powerful vibration

2. low amplitude - weaker vibration

gestation:

sense of taste

flavour:

combo of olfactory and gustatory perception

olfactory bulb:

specialized brain structure at the top of the forebrain that interprets smells

olfaction:

sense of smell

path of smell

nose and throat → olfactory epithelium → olfactory bulb

path of touch sensation

mechanoreceptors → spine → somatosensory cortex

path of taste

Chemicals bond to the receptors → changes to electrical potentials → neurotransmitter release → sig transmitted to the brain stem

path way of sight

.... TBD

cortical homunculus:

spatially organized map of the body

constructive perception:

brain attempts to consturct model of external wolrd based on sensory input

sensory perception:

organce signals from enviro

mental model:

brain infers a model based on sensory input

action:

behAviour based on inferred model of enviro, NOT THE STIM ITSLF

illusions:

brain wrongly infering external enviro from sensory input

Bistable stimuli:

images the brain change change its mind when it views

Direct perception

: behaviour is directly based on sensory input from the enviro w/o constructio of mental models

bottom up processing:

does NOT need speciifc knowledge

top down processing:

leveraging knowledge or expectations that are not sensory stim to process it phenomic restoration

Phenomic restoration effect:

bottom up x top down

Sensations:

Features of environment used to create understanding of the world

Perception:

Combination of sensations arriving from sensory system and prior knowledge

Transduction:

Process where sensations are translated to electrochemical transmission of the brain

Typoglycaemia:

ability to read something without issue while the words arent spelt correctly

Mcgurk effect:

can lip read while listenin to speech

bottom up processing provides conflict w/ visual and auditory info

Colour blindness:

genetic disorder where ppl are blind to green or red colours

supports the trichromatic theory

3 properties of visual stimuli

1. image segmentation

2. death perception

3. object recognition

principles of gestalt:

organization of information

figure ground:

whats the figure and whats the background

gestalt principle

proximity:

we group stuff that are close together

gestalt principle

similarity:

we group stuff that are similar

gestalt principle

closure:

we fill in the shapes open lines bc we know what it is

gestalt principle

good continuation:

we like to go with the flow gestalt principle

common fate:

the tendency to perceive objects that are moving together as belonging together

gestalt principle

Viasual grouping:

combine spatially separate regions into unified wholes

binocular disparity:

our eyes have diffrent perceptives of the world due to where the image falls on the retina

type of depth perception

object blocking:

.... type of depth perception

motion parallax:

things close move fater than things farther

type of depth perception

stereopsis:

brain uses differences in dispariity to determine the depth of objects relative to fixation

object recognition:

matching an incoming stim to a stored rep in memory

template model:

matching an object stored in mem by point

identification of object recognition:

ability to identify the same object or person across variations

classification of object recognition:

recognizing an object as a member of a category even if one has never encountered that specifc example

Mental imagery

: ability to mentally recreate perceptual experience in the absense of sensory stim

dual coding theory:

human knowledge is represented in 2 separate imagery systems (images and labels)

aphantasia:

no visual imagery

hyperphantasia:

extremely vivid visual imagery

depictive representation:

analog code that maintains perceptual and spatial characteristic of objects

descriptive representations:

symbolic codes that convey abstract conceptual information

epiphenomenon:

by product of fundamental cog processes

Mental scanning:

does mental images maintian the spatial characteristics of physical stim

experimenter expectancy:

r accidentally convey anticipated results to pars, altering behaivour

demand characteristics:

pars inerpretations of r purpose subconsciously changes behaviour