AP Psych Unit 3 Sensations & Perception

Flashcards covering the basic principles of sensation and perception, influences on perception, vision, and other senses, based on David G. Myers' Psychology for AP®

Sensation

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

Example: Feeling the warmth of the sun on your skin.

Perception

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

Example: Recognizing a friend's face in a crowd.

Bottom-Up

Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.

Example: Noticing the individual features of a flower before recognizing it as a rose.

Top-Down

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Example: Reading a word with missing letters because you anticipate what it should be.

Selective

The focusing of conscious awareness on a particular stimulus.

Example: Concentrating on a conversation at a noisy party.

Inattentional

Failing to see visible objects when our attention is directed elsewhere.

Example: Missing a dancer in a gorilla suit in a video when told to count basketball passes.

Change

Failing to notice changes in the environment

Example: Not realizing that a person you're talking to has been replaced by someone else.

Transduction

Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells into neural impulses our brains can interpret.

Example: The eye converting light waves into neural signals.

Psychophysics

The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Example: Investigating how the brightness of a light affects our perception of it.

Absolute

The minimum stimulation necessary to detect a particular stimulus 50% of the time.

Example: The faintest sound a person can detect half the time.

Signal

A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness.

Example: A security guard noticing a faint alarm sound in a noisy environment.

Subliminal

Below one's absolute threshold for conscious awareness.

Example: A message flashed so quickly on a screen that you don't consciously perceive it.

Priming

The activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.

Example: Hearing the word 'doctor' and then quickly recognizing the word 'nurse'.

Difference

The minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (jnd).

Example: Noticing the difference between two slightly different shades of color.

Weber’s

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

Example: The weight needed to be added to a 100lb object versus a 10lb object to notice a difference.

Sensory

Diminished sensitivity as a consequence of constant stimulation.

Example: No longer smelling the scent of perfume you applied earlier.

Perceptual

A mental predisposition to perceive one thing and not another.

Example: Seeing a cloud as a familiar shape because of your expectations.

Extrasensory

The controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition.

Example: Claiming to know what someone is thinking (telepathy).

Parapsychology

The study of paranormal phenomena, including ESP and psychokinesis.

Example: Investigating claims of psychic abilities.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of comic rays to the long pulses of radio transmission.

Example: Shorter wavelengths correspond to blue light.

Hue

The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.

Example: Identifying a shirt as 'blue'.

Intensity

The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the wave’s amplitude.

Example: A bright light has high intensity.

Pupil

The adjustable opening in the center of the eye through which lights enters.

Example: The black circle in the center of your eye.

Iris

A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.

Example: The colored part of your eye (blue, brown, green, etc.).

Lens

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

Example: The part of the eye that focuses light, like a camera lens.

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.

Example: The back part of the eye that receives the focused light.

Accommodation

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

Example: Your eye adjusting to see a close-up object clearly.

Rods

Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond.

Example: Allows you to see in dark conditions.

Cones

Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

Example: Allows you to see color and detail in bright light.

Optic

The nerve that carries neural impulses from the eye to the brain.

Example: The pathway for visual information.

Blind

The point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.

Example: A spot in your vision where you cannot see.

Fovea

The central focal point in the retina, around the which the eye's cones cluster.

Example: The area of the retina with the sharpest vision.

Feature

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

Example: Specialized brain cells that recognize edges.

Parallel

The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving.

Example: Processing color, motion, form, and depth all at once.

Young-Helmholtz

The theory that the retina contains three different color receptors – one most sensitive to red, one to green, one to blue – which, when stimulated in combination can produce the perception of any color.

Example: Explains how we see a wide range of colors from only three receptor types.

Opponent-Process

The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

Example: After staring at a red image, you see a green afterimage.

Gestalt

An organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.

Example: Seeing a series of dots as a complete shape.

Figure-Ground

The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).

Example: Seeing words as distinct from the page they are printed on.

Grouping

The perceptual tendency to organize stimuli into coherent groups.

Example: Grouping nearby objects together to see patterns.

Depth

The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.

Example: Knowing how far away a car is while driving.

Visual

A laboratory device for testing depth perception in infants and young animals.

Example: Used to test if a baby perceives depth.

Binocular

Depth cues, such as retinal disparity, that depend on the use of two eyes.

Example: Requires both eyes to work.

Retinal

A binocular cue for perceiving depth. By comparing images from the retinas in the two eyes, the brain computes distance – the greater the disparity (difference) between the two images, the closer the object.

Example: The difference between the images your eyes see helps you judge how close something is.

Monocular

Depth cues, such as interposition and linear perspective, available to either eye alone.

Example: Judging distance with only one eye.

Phi

An illusion of movement created when two or more adjacent lights blink on and off in quick succession.

Example: It give the illusion that one light is moving back and forth between two locations when two lights are blinking on and off.

Perceptual

Perceiving objects as unchanging (having consistent shapes, size, lightness, and color) even as illumination and retinal images change.

Example: Knowing a door is rectangular even when you view it from an angle.

Color

Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.

Example: Knowing that a banana is yellow, even in dim light.

Perceptual

In vision, the ability to adjust to an artificially displaced or even inverted visual field.

Example: Being able to ride a bike even when the world is flipped upside down.

Audition

The sense or act of hearing.

Example: Listening to music.

Frequency

The number of complete wavelengths that pass a point in a given time (i.e. per second).

Example: Determines the pitch of a sound.

Pitch

A tone's experienced highness or lowness; depends on frequency.

Example: A high pitched sound like a whistle.

Middle

The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window.

Example: Amplifies sound vibrations.

Cochlea

A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlea trigger nerve impulses.

Example: Turns sound waves into nerve signals.

Inner

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

Example: The part of the ear responsible for hearing and balance.

Sensorineural

Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness.

Example: Hearing loss due to loud noise exposure.

Conduction

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

Example: Hearing loss due to earwax buildup.

Cochlea

A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.

Example: A electrical device that helps deaf people hear.

Place

In hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated.

Example: Different parts of the cochlea vibrate to different frequencies.

Frequency

In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch.

Example: Explains how we hear low-pitched sounds.

Gate-Control

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

Example: Rubbing an injury can reduce pain.

Kinesthesia

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

Example: Knowing where your hand is without looking.

Vestibular

The sense of body movement and position, including the sense of balance.

Example: Keeping your balance while walking.

Sensory

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

Example: Food tastes different when you have a cold and your nose is blocked.

Embodied

In psychological science, the influence of bodily sensations, gestures, and other states of cognitive preferences and judgments.

Example: Holding a warm drink makes you perceive others as warmer.