psych unit 1.6

sensation

sensation

Process by which our sensory receptors & nervous system receive & represent stimulus energies from our environment

sensory receptors

Sensory nerve endings that respond to stimuli

perception

Process of organizing & interpreting sensory information, enabling us to recognize meaningful objects & events

bottom-up processing

Feature analysis; analysis that begins with the sensory receptors & works up to the brain's integration of sensory information

top-down processing

Information processing guided by higher-level mental processes, as we construct perceptions we are drawing on our experiences & expectations

selective attention

Focusing of conscious awareness on a particular stimulus in our environment

Cocktail party effect

In a group, we draw our attention from a conversation if we hear our name from across the room

selective inattention

Screening out of unwanted stimuli because it causes anxiety, feels threatening, or is of no importance; "you hear what you want to hear"

divided attention

Focusing on two or more tasks/stimuli; multitasking

inattentional blindness

Failing to see visible objects when our attention is directed elsewhere

change blindness

Failing to notice changes in the environment when our attention is directed elsewhere

pop-out

Stimuli that is so powerful & striking that we instantly notice a difference

transduction

Transformation/conversion of one form of energy into another

eye receives light energy and transduces it into neural messages

transforms electromagnetic energy received by vision into elecr\trochemical energy the brain can understand

absolute threshold

Minimum stimulus energy needed to detect a particular stimulus 50% of the time

Gustav Fechner

signal detection theory

Way to measure how we recognize a faint stimulus (signal) that conveys information & separate it from random background stimulation (noise)

subliminal

Below one's absolute threshold for conscious awareness that cannot be detected 50% of the time

priming

Activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response

difference threshold (JND)

Just noticeable difference; minimum difference between two stimuli required for detection 50% of the time; detectable difference increases with the size of the stimulus

Weber's law

Principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant number)

sensory adaptation

Neural adaptation; diminished sensitivity as a consequence of constant stimulation

habituation

Occurs when we stop having an interest in a stimulus or lack attention to it

dishabituation

Change in stimulus (even a small change) causes us to notice the stimulus again

wavelength

Distance from the peak of one light or sound wave to the peak of the next

hue

Dimension of color that is determined by the wavelength of light

amplitude

height

intensity

Amount of energy in a light wave or sound wave, which influences was we perceive as brightness or loudness

visual accommodation

Process by which the eye's lens changes shape to focus near or far objects on the retina; flips images & focuses inverted image

Young-Helmholtz Trichromatic

The retina contains three different color receptors (red, green, blue) which when stimulated in combination can produce the perception of any color

Opponent-Process Theory

Opposing retinal processes (red/green, yellow/blue and white/black) enable color vision; in the retina and in the thalamus some neurons are turned "on" by one color in the pair and turned "off" by the other and vice versa

afterimage effect

Visual sensation that remains after the stimulus is removed

feature detections

Nerve cells in the brain's visual cortex that response to specific features of stimulus- shapes, angles & movement

parallel processing

Processing many aspects of a problem simultaneously

Gestalt

An organized whole

convergence

Inward angles of the eyes focusing on a near object

Phi phenomenon

An illusion of movement created when two or more adjacent lights blink on & off in quick succession

audition

Sense or act of hearing

frequency

Number of complete wavelengths that pass a point in a given time; determine pitch

pitch

Highness or lowness of a tone

Sensorineural hearing loss

Nerve deafness

cochlear implant

Device for converting sounds into electrical signals & stimulating the auditory nerve though electrodes threaded into the cochlea

conduction hearing loss

Caused by damage to the mechanical system (eardrum & middle ear bones) that conduct sound waves to the cochlea

place theory

Determines high pitched sounds

frequency theory

Determines low pitched sounds

hairy skin

Skin that contains hair cells which detect movement & pressure

glabrous skin

Skin that contains no hair cells & receptors are sensitive

Gate-control theory

Spinal cord contains a neurological gate that controls the transmission of pain message to the brain; when tit opens we feel pain; when its closed we don't feel pain or pain is blocked

Ronald Melzack, Patrick Wall

gustation

Sense of taste

olfaction

sense of smell

in olfactory system

kinesthesia

Our system for sensing the position & movement of individual body parts

vestibular sense

Body movement & position including the sense of balance

sensory interaction

One sense may influence another

synthesia

the stimulation of one sense triggers the involuntary trigger of another sense

optical illusion

images we perceive differently than they are really seen

when our eyes send information to the brain that tricks us into perceiving something that does not match reality

cornea

clear protective outer layer covering the pupil and iris

bends light to provide focus

pupil

adjustable opening in the center

light passes through

iris

surrounding the pupil

controls size of pupil opening

colored part of eye

lens

bends wave flips image

retina

contains rods and cones

rods

low/dim light

black, white, gray

cones

determine color

fine lines, details

fovea

focuses vision

bipolar cells

connect outer and inner retina

activate ganglion cells

ganglion cells

inner retina

transport information about visual signals from bipolar cells

optic nerve

carries impulses form eye to brain

strabismus

misaligned eyes

glaucoma

damage to optic nerve

destroys vision

conjunctivitis

pink eye

cataracts

proteins in lens break down and create cloudiness in the eye

blind spot

the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

mypoia

nearsightedness

presbyopia

farsightedness

dark adaptation

adapt to quickly darkening conditions

saccade

reflexive rapid movement from side to side

fills in missing info from blind spot

astigmatism

blurriness at any distance

light adaptation

adapt to quickly lightening conditions

color vision deficiency

Inability to distinguish certain colors

1 in 50, usually male (genetic)

short, medium, or long wavelength cones in fovea

monochromatism

all color shows as one

dichromatism

can only see two colors

prosopagnosia

inability to recognize familiar faces

blindisight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

pinna

outer ear

collect sound waves

auditory canal

outer ear

funnel sound waves

eardrum/ tympanic membrane

end of ear canal

vibrate the waves

the ossicles

middle ear

malleus, incus, staples

amplify the waves

volley theory

assist low pitch sound

neural cells can alternate firing

sound localization

anything heard on the left side goes to the left side first and then transmits to the right

any sounds behind, infront, below, or above are harder to localize

phermones

help in development, survival, protection, social interaction

chemical signal

urine, sweat, saliva

tastes

sweet, sour, salty, bitter, umami, oleogustus

taste buds

decline with age

tongue has papillae with taste buds

taste bud - medulla - pons - thalamus - gustatory area or cerebral cortex

hot

warm and cold = hot

touch

essential for development

semicircular canals

sense the rotational movements of the body, help balance

visceral pain

internal organs

refered pain

body surface

somatic pain

skin, joints, muscles, tendons

limbic system

amygdala and hippocampus connect to olfactory nerves in nose that trigger memories

change deafness

don't recognize voices changing

method of right and wrong

stimuli is presented randomly rather than in ascending or descending order; prevent expectations and responding too quickly

method of adjustment

individual is in control of stimulus level