ap psych

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Sensory adaptation

The process in which sensitivity to a stimulus decreases over time as one is exposed to it.

Prosopagnosia

A neurological condition characterized by the inability to recognize faces, related to perception rather than sensation.

Bottom-up processing

Processing that begins with a stimulus and builds up to a final perception.

Top-down processing

Processing that begins with our thoughts, expectations, or prior knowledge to interpret sensory information.

Absolute threshold

The minimum stimulation needed to detect a particular stimulus 50% of the time; it can vary between individuals.

Difference threshold

The minimum difference between two stimuli required for detection 50% of the time, explained by Weber’s Law.

Subliminal message

A signal or message designed to pass below the normal limits of perception.

Perceptual set

A mental predisposition to perceive one thing and not another.

Transduction

The process of converting one form of energy into another, such as transforming sensory input into neural signals.

Selective attention

The focusing of conscious awareness on a particular stimulus, while ignoring others.

Inattentional blindness

A psychological lack of attention that is not associated with any vision defects or deficits.

Signal detection theory

A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation.

Accommodation

The process by which the eye's lens changes shape to focus near or far objects.

Opponent-process theory

A theory of color vision that proposes the existence of opposing color channels: red-green, blue-yellow, and black-white.

Young-Helmholtz Trichromatic Theory

A theory of color vision that suggests the retina contains three types of color receptors (red, green, blue), which combine to produce the perception of color.

After-images

Visual sensations that occur after the stimulus has been removed, often explained by the opponent-process theory.

Cornea

The clear, protective outer layer of the eye that helps focus light.

Iris

The colored part of the eye that controls the size of the pupil and thus the amount of light that enters.

Pupil

The adjustable opening in the center of the iris that allows light to enter the eye.

Lens

The flexible structure behind the pupil that changes shape to help focus images on the retina.

Retina

The light-sensitive inner surface of the eye that contains receptors (rods and cones) that process visual information.

Rods

Photoreceptor cells in the retina that are sensitive to light and enable us to see in low-light conditions.

Cones

Photoreceptor cells in the retina that are responsible for color vision and function best in bright light.

Blind spot

The point at which the optic nerve leaves the eye; it has no photoreceptors and thus does not respond to visual information.

Pitch

Determined by the frequency of sound waves; higher frequencies produce higher pitches.

Cochlea

A coiled, bony structure in the inner ear that contains fluid and the sensory receptors for hearing; cochlear implants help restore hearing by converting sound into electrical signals.

Eardrum

A thin membrane that vibrates in response to sound waves, transmitting sound to the ossicles.

Ossicles

The three tiny bones in the middle ear (malleus, incus, stapes) that amplify sound vibrations.

Semicircular canals

Fluid-filled structures in the inner ear that help maintain balance and spatial orientation.

Pathway for hearing

Sound waves travel through the outer ear, vibrate the eardrum, and are transmitted through the ossicles to the cochlea.

Conduction deafness

Hearing loss caused by damage to the mechanical systems that conduct sound waves to the cochlea.

Sensorineural deafness

Hearing loss caused by damage to the cochlea's receptor cells or the auditory nerve.

Place theory

The theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

Frequency theory

The theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, allowing us to perceive its pitch.

Vestibular sense

The sense that helps us maintain balance and spatial orientation through the detection of head position and movement.

Kinesthesis

The sense that provides information about the position and movement of our body parts, located in muscles and joints.

Five primary tastes

Sweet, sour, salty, bitter, and umami (savory).

Pain processing

Involves both sensory input and emotional response; it is processed in several areas of the brain, including the thalamus, somatosensory cortex, and limbic system.

Taste and smell

Considered chemical senses, as they detect chemical substances in the environment.

Monocular depth cues

Depth cues that can be perceived with one eye; examples include relative size, linear perspective, interposition, and relative height.

Binocular depth cues

Depth cues that require both eyes for perception; examples include retinal disparity and convergence.

Gestalt Theory

A theory suggesting that we perceive whole forms or patterns rather than just the sum of their parts.

Figure ground

The organization of the visual field into objects that stand out from their surroundings.

Closure

The tendency to perceive incomplete figures as complete.

Proximity

The principle that objects that are close together tend to be grouped together.

Similarity

The principle that objects that are similar in appearance are grouped together.

Visual cliff experiment

An experiment that demonstrated depth perception in infants, suggesting they can perceive depth even early in life.

ESP (extrasensory perception)

The ability to gain information without the use of the known human senses, often studied in psychology for validation of claims.

ESP and psychological research

Research investigates the validity of ESP claims through controlled experiments to determine if they can be reliably demonstrated.