psych unit 4

sensation

process in which our sensory receptors receive info from our environment

perception

process of organizing and interpreting sensory information into meaningful objects/ events

kinesthetic

gives feedback about position of orientation of specific body parts

vestibular

how our body is oriented in space; influences balance; works with semicircular canals

transduction

energy from outside is converted into neural impulses to be processed by our brains

bottom up processing

analysis that begins with sensory receptors and works up to sensory interpretation; 1st. sensory reception, 2nd interpretation is formed

top down processing

perception is based off previous events; previous experience and expectations effect the detection and analyses of info from the senses; explains visual illusions

signal detection theory

predicts how when a person detects a signal how loud/intense a noise is + how alert you are

absolute threshold

minimum stimulation needed to register an external stimuli 50% of the time

JND / difference threshold

minimum change in a stimulus that can just barely be treated

webers law

the size of the JND is a constant proportion of the size of the initial stimulus; percent change matters to JND, not amount

perceptual set

a mental predisposition to perceive one thing and not another; form of top down processing

cocktail party effect

ability to filter out all stimuli except what is important to us

context effect

the influence of the surrounding environment/situation on a person's perception

sensory adaptation

diminished sensitivity over constant stimulation

perceptual adaptation

adjustments of how we adapt to environment and filter our distractions

perceptual constancy

our perception that objects do not change ; color and size

color in terms of perpetual constancy

our ability to perceive an object as the same color regardless of environment

size in terms of perpetual constancy

objects remain same regardless of distance

cornea

first layer of eye; clear protective layer

iris

2nd part of eye; forms colored portion of eye; controls size of pupil opening

pupil

3rd; opening of the eye through which the the eye enters

lens

4th; changes its shape to help focus images on retina

fovea

5th; the central focal point in the retina of the eye around which cone cells cluster, providing the sharpest and most detailed color vision

retina

6th; contains rods, cones and layers of neurons that process visual info

photoreceptors

where transduction occurs

rods

100 million within; functions in dim light; detects black and white vision necessary for peripheral & twilight vision

cones

6 million within; near fovea (center of retina); function in bright light or daylight; detects fine detail color perception

optic nerve

7th; transmit visual info from retina to the brain

blind spot

point of exit for ganglion cell axons. no photoreceptors

brightness (intensity)

high amplitude = high brightness; determined by amplitude; related to perceived brightness

color

dimension of color determined by length of wavelength of ion; short wavelength = blue, long wavelength = red

trichromatic (young-helmholtz) theory

suggests that retina cones contain three receptors sensitive to red, blue, and green

opponent process theory

hering proposed that we process four primary colors opposed in parts of red-green, yellow-blue and black-white

afterimages

an image that remains after the stimuli to the retina has ended

color blind

prevents from discriminating between certain colors due to weakness in one of the cones: most common: red and green

innattentional blindness

failure to see objects in visual field when attention is directed elsewhere

change blindness

failure to notice changes overtime in the environment

prosopagnosia

neurological condition characterized by the inability to recognize the faces of unfamiliar people

pitch

size of wavelength/frequency relating to perceived pitch; long WL - low pitch, short WL, high pitch.

semicircular canal

fluid filled channels that help maintain balance

place theory

sound frequencies stimulate basilar membrane on specific hair cells (places) resulting in perceived pitch

frequency theory

nerve impulses traveling in auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch

accommodation

The process where the ciliary muscles change the shape of the eye's lens to focus light and images clearly onto the retina.

volley theory

idea that groups of auditory neurons fire in rapid, staggered turns, so combining their combining firing rate can match sound frequencies higher than any single neurons max rate, explaining perception of mid range pitches

sound localization

the ability to identify where a sound is coming from using binaural cues of which ear hears it louder and which ear hears it first

conduction deafness

problem transfering soundwaves anywhere along the the route through the outer or middle ear; hearing aids help combat this

sensorineural deafness

damage to inner ear (cochlea, hair cells); can be by excessively loud sounds, earbuds, or concerts; implants help

sensory interaction

principle that the senses all influence and work with each other to shape our perception

ganglion cells

specialized neurons in the retina that receive visual signals from bipolar cells and package them to send them to the brain

dichromatism

partial color blindness; one of the three cone photoreceptor types are malfunctioning or missing

monochromotism

full color blindness; the entire world is seen to them in grey, black and white; rare compared to dichromatism

blindsight

neurological condition in which people can respond to visual stimuli without needing to consciously experience them/ being aware of seeing them

olfaction

chemical sense of smell; only sense that does NOT pass through thalamus

pheremones

chemical signals released by an organism that triggers a behavioral or physiological response by something of the same species

olfactory system

system responsible for smell; instead of going through to the thalamus, they go through the limbic system (amygdala and hippocampus), which explains why some odors produce vivid mental and/or physical responses

gustation

chemical sense of taste, sensory experience of when food molecules interact with specialized receptor cells on tongue

super taster

a person with more taste receptors than the average person, causing a heightened sensitivity to tastes, especially bitterness that medium tasters or non tasters

warm and cold receptors (thermoreptors)

within the skin; detects changes in temperature and sends the signals of which to the brain

gate control theory

theory that proposes that the spinal cord contains a neurological "gate" that either blocks pain signals or allows them to pass to the brain

phantom limb sensation

the experience of sensation ( pain,touch,pressure, temp, or movement) within an amputated body part

gestalt psychology

the perceptual tendency to organize stimuli into content groups

schemas

mental framework to organize, interpret, and process info from enviorment

closure

group of disconnected pieces of information into a meaningful whole; part of geshalt

figure ground

perceive objects (figures) as distinct from their background (ground); part of gestalt

proximity

perceive objects as belonging together based on their proximity to each other; part of gestalt

similarity

group objects that similar characteristics; part of gestalt

selective attention

cognitive process of focusing of specific stimuli or tasks while ignoring irrelevant background info/distractions

motion perception/apparent movement

phi phenomenon; the illusion of movement created by presenting visual stimuli in rapid sucession

binocular cues

the information taken in by both eyes

depth perception/ convergence

ability to gauge length, width, and depth and to judge how far away an object is due to the eyes turning toward each other when focusing on an object

monocular cues

cues to help perceive depth without a need for both eyes

linear perspective

aka ponzo illusion; lines that seem to converge in an image to perceive depth; monocular cue

relative clarity

nearby objects are clearer than more distant objects

relative height

near objects are low in the visual field while far objects are higher up

texture gradient

texture of objects appears to change with distance

relative size

an object that appears larger than another object is believed to be of the same size just closer

interposition

objects that are observed by other objects are perceived as being far away

retinal disparity

where the brain compares the images projected onto the left and right retina due to their distance apart