AP Psychology Unit 1: Sensation

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from out environment

perception

the process of organizing and interpreting sensory info to make sense of the world around us. It involves the brain’s interpretation of sensory inputs, influenced by experiences, expectations, and context.

transduction

the conversion of sensory stimuli into neural impulses that can be understood by the brain; physical energy to electrochemical signals

absolute threshold

the point at which a stimulus is able to be detected by a sensory system

just-noticeable difference (JND)

the smallest change in a stimulus that can be detected as a difference by an individual

Weber’s Law

the perceived difference in a stimulus must be proportional to the original intensity of the stimulus

sensory adaptation

the process by which sensory receptors becomes less responsive to constant stimuli over time

synthesia

a condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway

retina

the light sensitive inner surface of the eye; contains photo receptor cells that convert light into

rods

photoreceptor cells in the retina responsible for detecting motion and vision in low-light conditions, providing black-and-white vision

cones

photoreceptor cells in the retina responsible for color vision, detail in bright light, and fine visual details like reading text and distinguishing between hues

fovea

central area of the retina responsible for sharp central vision; contains a high concentration of cone cells (no rods), enabling color vision

blind spot

area on the retina where the optic nerve exits the eye, lacking photoreceptor cells; a spot where vision is absent

ganglion cells

neurons in the retina that receive visual info from bipolar cells and transmit it to the brain via the optic nerve

lens

transparent structure in the eye that focuses light onto the retina by adjusting shapes, enabling clear vision at different distances

accomodation

the process by which the lens of the eye changes its shape

nearsightedness

a common vision condition where close objects appear clear, but distant objects appear blurry; occurs when the eyeball is too long or the cornea is too curved

farsightedness

a vision condition where objects are seen more clearly, but close objects appear blurry

trichromatic theory

proposes that color vision is based on 3 types of cone receptors (red, green, blue), each sensitive to different wavelengths of light

opponent-process theory

proposes that color vision is based on pairs of opposing color processes: red-green, blue-yellow, black-white; creates after images of the opposite color

afterimages

visual sensations that persist after a stimulus is removed; occurs due to temporary overstimulation of cone cells in the retina, causing an inverted or complementary image

dichromatism

a type of color vision deficiency where an individual only has 2 (instead of 3) types of functioning cone cells; causes difficulty in distinguishing between reds and greens

monochromatism

a rare form of color blindness where an individual has only 1 or no functioning cone cells; results in seeing the world in shades of gray

blindsight

a phenomenon where individuals with damage to their visual cortex can respond to visual stimuli without consciously perceiving them

prosopagnosia

aka face blindness; a neurological condition characterized by the inability to recognize familiar faces, including one’s own face

wavelength

distance between sound wave peaks; longer wavelengths = lower pitched sounds, shorter wavelengths = higher pitched sounds

amplitude

the measure of a sound wave’s intensity in loudness; represented by the height of its peaks; high amplitude = high sounds, low amplitude = low sounds

pitch perception

the brain’s interpretation of soundwave frequency, determining low or high tones in sounds

place theory

the idea that diff