Exam

problem of univariance

different wavelength combinations elicit the same response from a single photoreceptor

young helmholtz theory

trichromatic colour vision

3 photoreceptor’s sensitivity to particular wavelength

opponent colour theory

colour perception is based off of red-green, blue-yellow, black-white

achromatopsia

inability to perceive colour

deuteranope

no M cones

protanope

no L cones

tritanope

no S cones

Reichardt detector

hypothetical neural circuits for how the brain can track motion.

a cell in the brain receives input from two receptors in the eye (A then B), the input from A is delayed

MT / V5

selective for motion in a particular direction

directionally tuned

optic flow

perceptive changes as you move through the world

akinetopsia

no reception of motion

MT lesions

superior colliculus

midbrain area that guides eye movement

compensation theory

information about eye movement is discounted from retinal image

efference copy sent to comparator

parallax

information taken from 2 eyes at the same time is different

uses stereopsis (two different 2D images on retina create 3D perception)

stereopsis

using binocular disparity as depth cues

texture gradient

same sized objects appear smaller the farther they are from the viewer

anamorphosis

specific POV is needed to view a distorted image

motion parallax

objects appear to move faster the closer they are to the viewer

strabismus

the eyes are misaligned, childhood visual disorder

inhibition of return

difficulty getting attention back to recently attended location

peripheral/exogenous/stimulus driven cues have this

feature integration theory

preattentive stage - basic features are processes in parallel

attentive stage - binding features to items in serial search

guided search theory

items are searched based on basic features

premotor theory of attention

covert attention - inhibiting oculomotor program

overt attention - allowing eye movement

dorsal attention network

endogenous + exogenous attention

goal directed

ventral attentional network

exogenous attention

salient, right hemisphere only

milan cathedral experiment

visual imagery is impaired in spatial neglect patients

extinction

inability to detected contralesional stimuli when presented with ipsilesional one

ataxia

reduced spatial localization

simultanagnosia

inability to perceive more than one object at a time

apraxia

reduced eye movement

Balint’s syndrome

ataxia, simultanagnosia, apraxia

loss of global perception

idealism

reality is inseparable from perception

reality is a mental construct

superior temporal sulcus pathway

biological motion & social perception

peceptual committe models

middle vision is a collection of “specialists” who vote on their opinion

pandemonium model

minimum visual angle

0\.017deg

magnocellular

layers 1 & 2 of LGN

high luminance sensitivity & motion

take in rod information

parvocellular

layers 3-6 of LGN

high spatial frequency & colour

take in cone information

235

ipsilateral LGN layers

146

contralateral LGN layers

doctrine of specific nerve energies

sensation depends on which neurons are stimulated, not how they are stimulated

spectrum

representation of the relative energy present at each frequency

place code

location stimulated in cochlea determines frequency coded

threshold tuning curve

map of neural response to sine waves at lowest intensity

isointensity curve

fibers firing rate to many frequencies at same intensity

phase locking

firing of a single neuron at a distinct point in the sine wave at a given frequency

volley principle

multiple neurons fire at distinct points in the sine wave at a given frequency which codes for a distinct sound

equal loudness curve

sounds placed at a constant level are perceived as louder when played for longer

head directional transfer function

different intensities of the same sound hit the ear based on how they traveled (azimuth & elevation), providing depth to auditory cues

formants

concentrations in energy occur at different frequencies depending on length of vocal tract

spectral contrast

syllables are perceives based on change of relative energy (change in the spectrum)

analgesia

decreased pain when conscious

substantia gelatinosa

location of pain feedback circuit

gate control theory of pain

anterior cingulate

responds to hypnotic suggestion of water temperature

haptic perception

active exploration, sense derived from mechanoreceptors

exploratory procedure

hand movement pattern used to contact objects to perceive their properties

macula

detects linear acceleration and gravity

in otolith organs

anosmia

loss of smell

entorhinal cortex

mediates information to/from hippocampus

cross adaptation

reduced detection of a new odor after exposure to other odors that stimulate the same olfactory receptors

insular cortex

primary taste processing area

perceptual capture

dominance of one sense over other modalities in creating a percept

angular gyrus

may be the brain region responsible for out of body experiences