AP Psychology Unit 3 - Gumpf

sensation

physical simulation of the receptor cells

perception

the selection, organization, and interpretation of the sensory input

psychophysics

study of the relationship between the physical stimuli and the mental phenomena

absolute threshold

the minimum (weakest) level of energy you can detect 50% of the time

difference threshold

the minimum (smallest) level of change in energy you can detect 50% of the time

weber’s law

the just noticeable difference (JND) is a constant proportion of the original stimulus

fechner’s law

psychophysical scaling

• constant increases in physical energy will produce progressively smaller increases in perceived stimulus size

signal detection theory

stimulus detection is based on intensity of the stimulus and the individual’s psychological state/decision process

• proposes that there is no single absolute threshold and that perception of a stimulus depends partly on a person’s attitude, expectations, motivation, and alertness

adaptation

diminished sensitivity to a constant, unchanging stimulus

habituation

decreased responsiveness to a repeated stimulus

perceptual set

mental predisposition or readiness to perceive a stimulus due to past experience or provided information

selective attention

focusing conscious awareness on a particular stimulus while ignoring others

parts of the eye (pathway of light)

• cornea = outer covering of the eye

• pupil = the adjustable opening in the center of the eye through which light enters

• iris = a ring of muscle tissue that forms the color portion of the eye around the pupil and control the size of the pupil opening

• lens = transparent structure behind the pupil that changes shape to help focus images on the retina

• retina = light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

rods

retina

• low light vision

• no color

cones

retina

• color vision

• visual acuity

visual agnosia

an impairment in recognizing visually presented objects

• ex. trouble recognizing body parts

trichromatic theory

Young-Helmholtz

• the retina contains red, green, and blue photoreceptors that respond to various light wavelengths

• depending on timing, intensity, and which cones are stimulate different color potentials will be activated

• helps to understand color deficiency

opponent processing theory

Ewald Hering

• cones are linked together in antagonistic pairs (red-green, blue-yellow, black-white)

• only one color of the pair can activate a neural signal at a single time

• explains the occurrence of afterimages

subtractive vs additive color mixing

• subtractive = occurs when we mix paints or other colored material

• additive = occurs when we mix lights of different colors

phi phenomenon

an illusion of movement that arises when stationary objects are placed side by side and illuminated rapidly one after another

figure-ground perception

our tendency to organize the visual field into objects that stand out from their surroundings (the ground)

law of pragnanz

the perceptual tendency to organize stimuli into the least complicated forms

• law of simplicity

gestalt beliefs of perception

1. figure-ground

2. grouping = proximity, similarity, continuity and closure

3. law of pragnanz (simplicity)

binocular disparity and depth cues

visual information from two eyes enabling us to determine the distance of objects

monocular depth cues

visual information from one eye enabling us to determine the distance of objects

visual cliff

involves an apparent, but not actual, drop from one surface to another

perceptual constancies

our ability to see familiar objects as unchanging even as lighting, angles, and distance varies

distal stimulus

the actual object/event in the real world

• dista = distance/further away

proximal stimulus

the pattern of energy hitting the sensory receptors

• proximal = proximity/close

feature analysis theory

the possibility that humans and animals have neurons and neural networks that function as detectors, observing the individual characteristics, or features of every object and pattern we encounter

parts of the ear

1. outer ear

2. middle ear

3. inner ear

perceptive deafness

sensorineural deafness

• hearing loss cause by damage to the cochlea’s receptor cells or to the auditory nerves

conductive deafness

hearing loss caused by damage to the mechanical system that conducts sounds waves to the cochlea

vestibular system

sensory system that provides our brain with information about motion, head position, and spatial orientation

• involved with motor functions that allow us to keep our balance, stabilize our head and body during movement, and maintain posture

place theory

pitch perception is linked to the location of the basilar membrane that is stimulated by the sound wave

• stimulation location = pitch

  • high frequency = toward cochlea entrance

  • low frequency = toward middle

volley thoery

proposes that groups of neurons fire slightly out of sequence with each other, and when combined a higher frequency sound can be encoded

cocktail party effect

• ability to focus attention on one conversation in a crowded room, while filtering out other conversations

• allows us to eavesdrop in a crowded roomed but will not recall information in a rejected conversation

dichotic listening

research technique

• participants wear headphones that send a different message to each ear

  • supports the power of auditory selective attention

gustatory system

contributes to the flavor of foods and beverages and communicates information about ntrients and poisons

olfactory system

the bodily structures that serve the sense of smell

sensation of touch

mediated by mechanosensory neurons that are embedded in skin and relay signals from the periphery to the central nervous system

gate control theory

proposition that the spinal cord contains a neurological “gate” that blocks or allows pain signals to pass on to the brain

• fast pain pathway

• slow pain pathway

• the “gate”

kinesthetic system

made up on sensory receptors throughout the body, notably proprioceptors, which detect movement and position of joints and limbs

• knowing the position and movement of your body parts without looking

fast pain pathway

• sharp localized pain

• large myelinated nerve fibers

• closes the gate

slow pain pathway

• aching, less localized pain

• small, unmyelinated nerve fibers

• opens gates

the “gate”

descending signals originating in midbrain can block pain by also closing gate