AP Psychology (2024-2025) - Unit 1 - Sensation (3/3)

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

Transduction

The process of converting outside stimuli, such as light, into neural activity that the brain understands

absolute threshold

the minimum intensity of stimulation that must occur before you experience a sensation

Just Noticable Difference Threshold

the minimal change in a stimulus (that was already previously perceived) that can just barely be detected

Weber's Law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)

Sensory Adaptation

tendency of sensory receptor cells to become less responsive to an unchanging stimulus

Synesthesia

When the brain routes sensory information through information through multiple unrelated senses, which causes people to experience multiple senses at once

Retina

the 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

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

Cones

retinal receptor cells that are concentrated near the center of the retina and that detect detail and color. Used in bright environments

Fovea

the central focal point in the retina, around which the eye's cones cluster, allowing or focus

blind spot

the point at which the optic nerve leaves the eye due to no receptor cells being located there

ganglion cells

the specialized cells which lie behind the bipolar cells whose axons form the optic nerve which takes the information to the brain

Lens

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

accommodation

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

Nearsightedness

a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina

Farsightedness

a condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina

trichromatic theory

Visual theory, stated by Young and Helmholtz that all colors can be made by mixing the three basic colors: red, green, and blue

opponent-process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision.

Afterimages

images that occur when a visual sensation persists for a brief time even after the original stimulus is removed

Dichromatism

A type of color blindness where one of the three basic color mechanisms is absent or not functioning, making it hard to differentiate colors

Monochromatism

Color vision deficiency where only one or none of the cone receptors work, which results in the inability to perceive color.

Blindisght

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Prosopagnosia

inability to recognize faces despite being able to see clearly

Wavelength

The distance between soundwave peaks. Shorter ___________ high pitches, longer ___________ low pitches

Amplitude

The intensity of a soundwave depends on how high the peaks of the wave are. The higher the soundwave = the higher the ______

pitch perception

The brain's interpretation of the frequency of sound waves, determining whether a sound is high or low in tone. Higher frequencies are perceived as higher pitches, while lower frequencies are perceived as lower pitches.

place theory

in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated. The basal region hears higher pitches while the apical end hear lower pitches.

frequency theory

The frequency of a soundwave correlates with the rate at which auditory nerves fire

volley theory

Groups of auditory neurons fire in rapid succession, which helps us hear higher than 1000 Hz.

Sound localization

the process by which the location of sound is determined. Relies on arrival time and intensity between the ears and spectral cues.

Conduction Deafness

hearing loss caused by damage to the mechanical system in the middle ear that conducts sound waves to the cochlea

sensorineural hearing loss

the most common form of hearing loss, also called nerve deafness; caused by damage to the cochlea's receptor cells or to the auditory nerves

Sensory Interactions

the principle that one sense may influence another, as when the smell of food influences its taste

olfactory system

the sensory system for smell. Receptors within the nose send signals to the brain via the olfactory nerve

Pheromones

Chemical signals released by an animal or human that communicate information and affect the behavior of other animals of the same species.

Gustation

sense of taste that involves receptors on the tongue that detect different flavors

Sweet

energy source

Salty

sodium essential to physiological processes

Sour

potentially toxic acid

Bitter

potential poisons

umami

proteins to grow and repair tissue (debated on whether its a taste)

Olegustus

fats for energy, insulation, and cell growth

Supertasters

people with heightened sensitivity to all tastes and mouth sensations

Medium tasters

average ability tasters

Nontasters

Not so sensitive to taste, seek out relatively sweeter or fattier foods to maximize taste.

warm and cold receptors

thermoreceptors; recetpors on our skin that are either sensitive to warmth or to cold

Pain

an unpleasant sensory and emotional experience associated with actual or potential tissue damage. NOT a sensation.

gate-control theory

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "____" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

Phantom Limb

perceived sensation, following amputation of a limb, that the limb still exists

Vestibular Sense

the sense of body movement and position, including the sense of balance; equilibrium

semicircular canals

three canals within the inner ear that contain specialized receptor cells that generate nerve impulses with body movement and help maintain balance. It looks like a 3D pretzel

kinesthesis

the system for sensing the position and movement of individual body parts