psyc mid term

Illusion

Perception in which the way we perceive a stimulus doesn’t match it’s physical reality

sensation

detection of physical energy by sense organs, which then send information to the brain

perception

the brain’s interpretation of raw sensory inputs

Transduction

the process of converting an external energy or substance into electrical activity within neurons

sense receptor

specialized cell responsible for converting external stimuli into neural activity for a specific sensory system

sensory adaption

greatest when a stimulus is first detected

psychophysics

the study of how we perceive sensory stimuli based on their physical characteristics

absolute threshold

lowest level of stimulus needed for the nervous system to detect a change 50% of the time

JND

the smallest change in the intensity of a stimulus that we can detect

weber’s law

constant proportional relationship between JND and original stimulus intensity

signal detection theory

theory regarding how stimuli are detected under different conditions

Synesthesia

condition in which people experience cross-modal sensations

selective attention

allows us to select one channel and turn off the others, or at least turn down their volume

inattentional blindness

failure to detect stimuli that are in plain sight when our attention is focused elsewhere

hue

color of light

Visible light wavelength

Red 700 purple 400

additive color mixing

varying amounts of primary colors positively

subtractive color mixing

varying amounts of primary colors negatively

Sclera

The white of the eye

Iris

Colored part of the eye. Contains the muscles that control the pupil

Pupil

Circular hole through which light enters the eye. Controls how much light enter our eyes

Cornea

curved and transparent layer covering the iris and pupil. the shape bends light to focus the incoming image at the back of the eye.

Lens

Bends light but only through curvature to keep images in focus

accommodation

changing the shape of the lens to focus on objects near or far

Myopia

Nearsightedness Cornea too long

Hyperopia

Farsightedness. Cornea too short

Retina

Membrane at the back of the eye responsible for converting light into neural activity

Fovea

central part of the retina. Responsible for acuity

Acuity

sharpness of vision

Rods

Receptor cells in retina allowing us to see in low levels of light. More outer than in the centre

Dark adaptation

time in dark before rods regain maximum light sensitivity

Cones

Less of these. Sense color. Need more light

Rhodopsin

Photopigment in rods. needs vitamin A

Optic nerve

Travels from the retina to the brain

Optic chiasm

Fork in the road. Half of axons crossing and not

Optic tracts

Sends most of their axons to the thalamus, then to the primary visual cortex called V1

superior colliculus

Remaining Axons from the optic tracts go here. key role in reflexes

Blind spot

Place where the optic nerve connects to the retina

Feature detector cells

Detects lines and edges

Trichromatic theory

Idea that color vision is based on our sensitivity to three primary colors

Monochromats

One type of cone, lose all color vision

Opponent process theory

theory that we perceive colors in terms of three pairs of opponent colors: either red or green, blue or yellow, black or white.

Visual agnosia

Deficit in perceiving objects

Audition

sense of hearing

Pitch

frequency of a wave 20-20,000 Hz

Loudness

Amplitude/height of the sound (decibels dB)

Timbre

complexity or quality of sound that makes musical instruments, human voices, or

Cochlea

bony, spiral shaped sense organ used for hearing. converts vibration into neural activity

organ of corti

tissue containing the hair cells necessary for hearing

basilar membrane

membrane supporting the organ of Corti and hair cells in the cochlea

place theory

specific place along the basilar membrane matches a tone with a specific pitch

olfaction

our sense of smell

gustation

our sense of taste

taste buds

sense receptor in the tongue that responds to different foods through papillae

Pheromone

odorless chemical that serves as a social signal to members of one’s species

Vomeronasal organ

humans don’t have these. Detect pheromones

somatosensory

sense of touch, temperatures and pain

gate control model

idea that pain is blocked of gated from consciousness by neural mechanisms in spinal cord

phantom pain

pain or discomfort felt in an amputated limb

proprioception

our sense of body position

vestibular sense

our sense of equilibrium or balance

semicircular canals

three fluid filled canals in the inner ear responsible for our sense of balance

parallel processing

the ability to attend to many sense modalities simultaneously

bottom-up processing

in which a whole is constructed from parts

top down processing

conceptually driven. influenced by beliefs and expectations

perceptual set

set formed when expectations influence perceptions

perceptual constancy

the process by which we perceive stimuli consistently across varied conditions

color constancy

our ability to perceive color consistently across different levels of lighting

Gestalt principles

governing how we perceive objects as wholes within their overall context

Proximity

Physically close to each other tend to be unified in the brain

similarity

all things being equal, like rows of the same circle or a repeating pattern in a row

continuity

we still perceive objects as wholes even when things are blocked

Closure

partial visual information, we fill in what is missing

symmetry

symmetrically arranged as wholes

figure-ground

focus attention on what we believe to be the central figure, not the background

prosopagnosia

face blindness

fusiform gyrus

helps us form faces for recognition, when damaged causes prosopagnosia

depth perception

ability to judge distance and 3d relations

monocular depth cues

stimuli that enable us to judge depth with one eye only

binocular

depth perception using 2 eyes

binaural cue

how sounds arrive at our brain stem to determine where sounds are produced physically

subliminal perception

perception below the limen or threshold of conscious awareness

precognition

acquiring knowledge of future events before they occur

telepathy

reading other people’s minds

clairvoyance

detecting the presence of objects/people hidden away

Neurons

Nerve cell specialized for communication

Soma

central region of the neuron. Manufactors new components

Myelin sheath

a coatation of this allows electrical signals to travel faster

Dendrites

Portion of neuron that receives signals

branchlike

listen in

Axon

Portion of neuron that sends signals

thin near cell body

long tail

Synaptic vesicle

Spherical sac containing neurotransmitters

Neurotransmitter

Chemical messenger specialized for communication from neuron to neuron

Synapse

space between two connecting neurons though which messages are transmitted chemically

synaptic cleft

a gap into which neurotransmitters are released from the axon terminal

glial cell

cell in the nervous system that plays a role in the formation of myelin and the blood-brain barrier, respond to injury, removes debris and enhances learning and memory

Resting potential

Electrical charge difference (-60 millivolts) across the neuronal membrane when the neuron is not being stimulated or inhibited

Threshold

membrane potential necessary to trigger an action potential

action potential

electrical impulse that travels down the axon triggering the release of neurotransmitters

absolute refractory period

time during which another action potential is impossible; limits the maximal firing rate