Psychology Chp. 3

translates info from outside nervous system into neural activity giving nervous system knowledge of the world (initial message, not interpretation)

• 1. accessory structures
• 2. transduction
• 3. info relayed to thalamus
• 4. thalamus reroutes to appropriate place
• 5. interpretation of stimulus

captures and modifies stimulus energy

process that transforms physical energy into electrochemical signals (done w/ receptors)

relay station for pain and sense-organ signals

smallest amount of energy required for person to report a stimulus on half of the trials

assesses persons sensitivity to stimulus and criterion for saying they detect a stimulus

difference threshold proportional to intensity of the stimulus

point at which pair of stimuli are recognized as being different half of the time

translation of physical properties of stimulus into a unique pattern of neural activity (specifically identifies particular physical properties)

code physical properties of stimuli by responding to very specific features located in a more complex stimulus (responds to a unique code)

transparent bulge on the front of eye (light enters here)

an opening in the iris (light passes through pupil)

muscular disk controls amount of light entering eye

elastic membrane capsule

focus on distant objects

focus on nearby objects

• difficulty focusing on distant objects
• eyeball is too long and so focuses light rays in front of the retina

• difficulty focusing clearly on near objects
• eyeball is too short and so light rays focus behind the retina

• multilayered tissue located at rear of eyeball
• contains photoreceptors

• specialized nerve cells
• convert light energy into neural responses

black and white receptors - function best in dim light

color receptors - function best in bright light

carries neural signals to thalamus and then occipital lobe

light from different mixtures of wavelengths

• Trichromatic
• Dual process theory

any color can be matched by mixing lights of 3 wavelengths: blue, green and red (3 types of color receptors in retina)

• color processing occurs in 2 stages
• 1. retina's red/green/blue cones respond in varying degrees to light wavelengths
• 2. ganglion cells combine output of cones into red-green, blue-yellow, and black-white information

• Red or green sensitive cones done function properly
• vision is dichromatic instead of trichromatic
• difficut to distinguish red and green

process of how sensations are interpreted as meaningful experiences (compares w/ previous info)

• bottom-up
• feature
• top down

taking individual elements of stimulus and combining into unified whole

respond to selected, basic features of a stimulus - features recombined to create the perceptual whole

sensory information is interpreted in light of existing knowledge, ideas, and expectiation (prior experiences)

organize stimuli into a foreground figure and a background

• tend to perceive objects as groups rather than individual units:
• proximity - nearness
• similarity - likeness
• closure - incomplete figures as complete

perceived size/shape of objects remain same despite changes retinal image

parallel lines that are distant appear to converge toward a point on the horizon

distant object appears smaller than does same object close up

depth cues

perception of motion from series of "snapshot" images - each slightly different from previous one

series of lights flas on and off sequentially at alightly different locations - "moving light"

sensation

vision, hearing, taste, touch, and smell

sensory receptors

olfactory receptors

perceptual set (schema)

what you are expecting

selective attention