psych exam two

sensation

detection of physical energy

transduction

convert neural energy to neural impulses

perception

determine external world from sensory stimulation

sensory systems

5 senses

vestibular (balance)

proprioception/kinestensis (knowing how heavy something is)

somatic (heat, awaraness of pain, pressure, etc…)

law of specific nerve energies

signals one a sensory pathway are interpreted as that type of info

(example is that visual nerve stimulation will always appear as lights

synesthesia

inappropriately experiences senses across modalities

ex- seeing colors while reading or seeing a 3D calendar in space around your head

Distal Stimulus

reflects or radiates energy (light, sound, heat, etc…)

proximal stimulus

received via sense organs

(ex= vision on retinas…. interprets movies as if they are actually there)

(you can listen to music on earbuds but there is no one actually speaking)

psychophysics

relate physical properties with mental experiences

detection

determine whether a stimulus is present

absolute threshold is defined as 50% of the time you detect the trial

(there is subliminal and supra threshold ranges)

discrimination

detect a change in intensity or quality

just noticeable difference (JND) = the smallest detectable change

Weber’s Law

type of discrimination law

FRACTION

your ability to detect change is a ratio

Fechner’s Law

discrimination law

psychological experience is a log function of change multiplied by a constant

LOGRIMATTIC

we build this law into our devices (ie sound/volume buttons)

Stevens Law

log and log function… you get straight lines

POWER function

signal detection theory

types of responses

HITS = yes, correctt

MISSES = no, incorrect non identification

FALSE ALARM - yes, incorrect identification

CORRECT REJECTION= no, correct non identification

what are the only two single detection theories that you need

hits and false alarms

bias in signal detection theory

liberal = yes all the time

conservative = say yes only when certain

scelera

whites of our eyes

we want to see where other people are looking… this is because we are a social species

cornea

focuses light on the eyes

aqueous humor

provides nutrients and drainage

lens

made of cells and changes it shape to look close and far

-gets stiffer as we grow older

-you’ll need glasses

iris

colored part

pupil

hole in the eye

inverse relationship between iris and pupil

lowlight= larger pupil

bright = smaller pupil

vitreous humor

liquid filled space… no drainage

apparently dots in your vision are just floaters in this substance

retina

where detection of light/transduction occurs

fovea

center of vision

optic nerve

send back to visual processing

-tbh you are functionally blind in the eye, in order to ACTUALLY see the light must be sent back to the brain

myopia

nearsighted (eyeball too long)

hyperopia

farsightedness

eyeball too short

astigmatism

cornea imperfections

distortions in vision

presbyopia

lens stiffing

• can’t correct vision when things are too close to you

• (happens when you get old)

structures of retina

photoreceptors pointed towards back of the head

how many rods/cons are in each eye

130 million in each eye

how many optic nerves fibers are there and why is this an issue

because this is so fewer than the amount of rods/cones this is why there is a great compression of information

cones and rods see what

cones = color

rods = dark

fovea and the blind spot issue

-most of the cones (color receptors) are in the center of our eyes

-there are no rods in the fovea (they only exist primarily peripherally)

-so we see only a very small section of color right in the center of our vision and our brain tries to adjust for the rest

receptive fields

ON CENTER= cells fire when light are on their center

OFF CENTER = ganglion cells only fire when light is on in the periphery

together these two processes make our vision sharper so we can detect edges (this is the same system used by photocopying machines)

Dark Adaptation

takes 20-30 minutes to fully adjust (this is aligned with the time it takes for the sun to set #adaptationtotheworld)

-cones are much faster at doing this than rods

-lowkey we can actually see very well in the dark, we just never actually have the oppurutnity to try with light pollution

what spectrum of light can we see and why

we can see visible light because it is useful to us… the rest aren’t

color is a mental contrast…. the interpretation is all in our head

non spectral hues

colors that are made up of combinations of wavelengths…. ex=magenta 

hue

dominate wavelength of color

brightness

amplitude (intensity)

saturation

purity (quality of primary wavelength)

black vs white

black absorbs all wavelengths while white reflects them all 

subtractive mixture

taking wavelength out

ex= mixing paint and getting black

addititive color mixing

add different wavelengths and get white

trichromatic color vision (young-helmoltz theory)

3 color receptores (cones)

red= long wavelengths

green = medium wavelengths

blue = short wavelengths

what causes color blindness?

one of the sets of cones in the retina is not missing or functioning properly

the gene for this mutant is on the x chromosome so males are much more likely to have it

photopigments

light sensitive molecules 

rods = rhodopsin 

cones = lodospins 

phototspin I = red = vitamin A

phtospin II = green

photospin III = blue 

opponent process color vision (hering’s theory)

6 systems in 3 pairs

HUE 

red-green system 

blue - yellow system 

BRIGHTNESS

black - white system 

the example of this is the green then red fox…. due to cell fatigue in your thalamus 

occipital color vision

color constancy

-wavelengths vary but the occipital lobe accounts for this

this

-this idea went on to help develop the color filter on the black white cameras with polaroid guy

pattern recognition

2-D proximal stimuli are viewed as 3D components

-the brain first identifies features (processed along different pathways)

-these features are then organized into objects

perceptual constancies 

color, size, shape 

the dorsal stream of visual pathway

where? how objects are arranged in space?

ventral stream of visual pathways

what objects are?

serial vs parallel processing

serial = one at a time

parallel = multiple at a time

many processes, including vision, is being done through parallel processing

Gestalt Organization Principles 

figure ground = look @ people in the background

proximity = things closed are grouped together 

similarity = grouped together must be similar 

good continuation = you want to put A with B and B with C

common fate = things that move together are automatically a group 

closure = if there are gaps… your brain automatically closes them because you want completion 

simplicity = assume the simplest solution 

subjective contours

you can see edges that don’t exist

side point to subjectivity:

F A TREE FALLS IT DOES NOT MAKE A SOUND…. sound is just a subjective experience that’s all in your head…. so is music

all is just your own interpretation of sound waves

monocular cues

only one eye needed

relative size - monocular

closer = larger retina image

farther away = smaller retina image

linear perspective- monocular

more divergences = closer

mosre convergence = farther awayo

occlusion - monocular

the one in the front is closer

textutal gradeint = monocular

the closer something is… the more details/texture can be seen

motion parallax - monocular

sitting on a train

things that tare closer feel like they’re going in opposite directions but things further away seem to go in the same direction

height in images = monocular

closer = lower

higher = further away

binocular disparitty

the two eyes receive two different images

the closer something is to you, the greater the disparity

binocular convergence

the closer something is, the more the eyes turn in

the further something is, the more they turn out

depth cues 

parallel lines in height and then arrows/corners that turn in and out 

moon illusion

feels like its larger when its at theta horizon rather than when it is overhead

-because the horizon is as far away as it can get but as it moves overhead there is a loss of depth so it appears to be smaller

motion perception

area MT in the temporal love

plays a roll in the phi phenomenon

phi phenomenon

the common fate…. when lights appear in sequence

also that waterfall allusion

-the cells in the Mt are getting fatigued so when you look away everything looks like it is going up

directions of perception

bottom up = what is in the world

top down = expectancies

interactive = bottom up and top down

goal = perceptual constancy

simple cells

respond to features in receptive field

play a role in the bottom up approach

complex cells

aggregates of simple cells

play a role in the bottom up approach

hypercomplex cells 

aggregates of complex cells 

specific shapes 

play a role in the bottom up approach

3D assembly (bidermans RBC theory)

recognization of an object by its components (geons)

kind of like legos

Auto kinetic Effect (still top down approach )

basically still things move slightly so that your eyes don’t get tired

the laser pointer spelling out words experiment

basically top down and bottom up are

top down = conceptually driven

bottom up = data driven

nativism vs empiricism for development 

nativism = knowledge needed for perception of the world is innate 

empiricism = knowledge needed for perception is learned 

visual deprivation

restricting visual inputs to a maturing organism

-afterwards subjects can only see vertical lines

visual distortion studies

-distorting normal vision in an experienced organism

• they adjust after a few minutets

if perception was hardwired this would not be possible (aka plasticity)

redirection of visual inputs…. shows alternation neural pathways

-CUT optic nerve in hamsters and redirected to temporal lobe and guess what it still worked

VISION IS NOT HARDWIRED

central processing is NOT

innate 

muller-lyer illusion

if you’re raised in a culture with few buildings /corners then you won’t see the in/out effect

visual agnosia/anomia

inability to identify objects

-happens after temporal lobe damage

-can not map visual experiences onto memories

prosopagnosia

inability to identify faces

impacts a part of the visual association cortex

they can describe faces but not pick out someone

can not identify even their own face

what is consciousness

a subjective experience 

-world, environment, mind etcp

phenomenology

refers to what consciousness feels like

problem of other minds

we can not perceive other’s consciousness so we infer from our own

principles of consciousness

feels like UNITY,

INTENTION - you can direct it

SELECTIVE - you can select what info to process

TRANSIENCE = it does not ever stop… it is always shifting

levels of consciousness

-minimal = interacting with environment

full = interacting with envriomentt but at the level of mammals

self = awareness of who you are (this is something you are born with…. why you recognize yourself in the mirror)

how can you measure consciousness

think aloud protocols

-most conscious thoughts are about sensory environment or current concerns

default mode network

comprehending , day dreaming, autobiographical remembering …. this is teh stuff you’re brain is doing when you are “doing nothing”

the unconsciousness 

thoughts outside of awareness

-bulk of our thinking 

• i.e we have no idea how we actually process language 

cognitive unconscious

dynamic = lots of processes

dual process theory:

fast = unconscious …. feelings and intuitions

slow = conscious … thinking through something

selective attention

attention selects things for further processing and filters out the rest

endogenous attention

directed by you

exogenous attention 

captured by the environment  t(ie a loud noise)

early filter theories

-dichoitc listening

-shadowing studies

early filter theory evidence

cocktail party effect

visual search studies

attention and visual search

feature search = pop out effect

conjunction search

illusory conjunctions (if you’re looking for a blue A you may just combine an A you see close to something blue)