unit 4,5,6

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

Bottom-Up Processing

analysis that begins with the sense receptors and works up to the brain's integration of sensory information

Top-Down Processing

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

Selective Attention

the focusing of conscious awareness on a particular stimulus

Inattentional Blindness

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

Change Blindness

failing to notice changes in the environment

Psychophysics

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

Absolute Threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

Signal Detection Theory

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 detection depends partly on a person's experience, expectations, motivation, and level of fatigue.

Subliminal Threshold

when stimuli are below ones absolute threshold for conscious awareness

Priming

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

Difference Threshold

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

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 Adaption

diminished sensitivity as a consequence of constant stimulation

Transduction

the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

Wavelength

The distance between crests of waves, which determines the hue (color) of what you see

Hue

another word for color; determined by the wavelength of light

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

Cornea

the clear tissue that covers the front of the eye

Pupil

the adjustable opening in the center of the eye through which light enters

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

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

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

Cones

Retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. There are about 6 million of them and they detect fine detail and give rise to color sensations

Rods

Retinal receptors that detect black, white, and gray. There are about 120 million of them and they are also responsible for peripheral vision and seeing in dim light

Optic Nerve

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

Blind Spot

the point in the retinal where the optic nerve leaves the retina, resulting in no rods or cones in that area

Fovea

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

Feature Detectors

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

Parallel Processing

the processing of several aspects of a stimulus simultaneously (color, motion, form, and depth

Parallel Distributed Processing

States that the interpretation of a stimuli is based on several areas of the brain simultaneously working together. Thus, you can smell/see/hear something and think of a memory

Convergence

Occurs when the eye muscles strain as a result from an object becoming too close to the eyes

Gestalt Psychology

a psychological approach that emphasizes that a whole object is greater than its parts

Opponent-Process Theory

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

Audition

the sense or act of hearing

Frequency

the number of waves produced in a given amount of time, which determines pitch

Pitch

the property of sound that varies with variation in the frequency of vibration

Outer Ear

the part of the ear that collects sound waves; consists of the pinna, the ear canal, and the eardrum

Middle Ear

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

Inner Ear

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

Cochlea

the snail-shaped tube (in the inner ear coiled around the modiolus) where sound vibrations are converted into nerve impulses by the Organ of Corti

Auditory Nerve

the nerve that carries impulses from the inner ear to the brain, resulting in the perception of sound

Place Theory

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

Frequency Theory

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

Kinesthesis

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

Vestibular Sense

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

Gate-control Theory

The theory that spinal cord contains neurological gate that blocks pains signals or allows them to pass. The gate is opened by activity of pain going up small nerve fibers & the gate is closed by act of large fibers or by info coming from brain

Sensory Interaction

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

Figure-Ground

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

Grouping

the perceptual tendency to organize stimuli into coherent groups (proximity, similarity, continuity, connectedness, and closure)

Depth Perception

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

Visual Cliff

a laboratory device for testing depth perception in infants and young animals

Binocular Cues

depth cues, such as retinal disparity and convergence, that depend on the use of two eyes

Retinal Disparity

a binocular cue for perceiving depth; by comparing images from the two eyeballs, the brain computes distance - the greater the disparity (difference) between the two images, the close the object

Monocular Cues

depth cues, such as interposition and linear perspective, available to either eye alone (relative height, relative size, interposition, linear perspective, relative motion, and light and shadow)

Relative Height

a monocular cue for perceiving depth; objects higher in our field of vision are perceived as farther away

Relative Size

a depth cue whereby larger objects are perceived as closer than smaller ones

Interposition

monocular visual cue in which two objects are in the same line of vision and one patially conceals the other, indicating that the first object concealed is further away

Linear Perspective

a monocular cue for perceiving depth; the more parallel lines converge, the greater their perceived distance

Relative Motion

a monocular cue for perceiving depth; while you are moving, the nearer an object is, the faster it seems to move

Light and Shadow

a monocular cue for perceiving depth; a dimmer object seems farther away

Phi Phenomenon

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

Perceptual Constancy

perceiving objects as unchanging even as illumination and retinal images change

Shape Constancy

tendency to see an object as the same shape no matter what angle it is viewed from

Size Constancy

perception of an object as the same size regardless of the distance from which it is viewed

Color Constancy

the tendency for a color to look the same under widely different viewing conditions

Perceptual Adaptation

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

Perceptual Set

a mental predisposition to perceive one thing and not another

Context Effects

the influences of the surrounding environment on perception

McGurk Effect

when the ear hears one sounds, but the eye sees a mouth form a different sound, the brain's interpretation can be a mixture of the two sounds

Moon Illusion

the moon looks larger when we see it on the horizon than when we see it in the sky. This is because the horizon contains visual cues that make the moon seem more distant than the overhead sky.

Ganglion Cells

neurons that connect the bipolar cells to the optic nerve; summarizes and organizes data from rods/cones and sends it to the brain

Olfactory Receptors

nerve endings that act as the receptors for the sense of smell

Nociceptors

Receptors in the skin that give rise to the sense of pain

Hair Cells

Receptor cells within the cochlea that transduce vibrations into nerve impulses

Vestibular Sacs

organs in the inner ear that connect the semicircular canals and the cochlea and contribute to the body's sense of balance

Phantom Limb Sensation

feelings of sensation in amputated limbs

Consciousness

our awareness of ourselves and our environment

REM Sleep

a recurring sleep stage during which vivid dreams commonly occur; brain is awake, but body cannot move

Circadian Rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

Alpha Waves

the relatively slow brain waves of a relaxed, awake state

Sleep

a natural and periodic state of rest during which consciousness of the world is suspended

90 minutes

A typical sleep cycle lasts...

Hallucinations

false sensory experiences, such as seeing something in the absence of an external visual stimulus

Delta Waves

the large, slow brain waves associated with deep sleep

NREM Sleep

Quiet, dreamless sleep cycle; divided into four stages;

Insomnia

recurring problems in falling or staying asleep

Narcolepsy

a sleep disorder characterized by uncontrollable sleep attacks. the sufferer may lapse directly into REM sleep, often at inopportune times

Sleep Apnea

a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings

Night Terrors

a sleep disorder characterized by high arousal and an appearance of being terrified; occur during Stage 4 sleep, within two or three hours of falling asleep, and are seldom remembered

Dream

a sequence of images, emotions, and thoughts passing through a sleeping person's mind

Manifest Content

according to Freud, the remembered story line of a dream

Latent Content

according to Freud, the underlying meaning of a dream

REM Rebound

the tendency for REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep)

Hypnosis

a social interaction in which one person suggests to another that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur

Posthypnotic Suggestion

a suggestion that is made to a person who is hypnotized that specifies an action he will perform (usually in response to a cue) after he has awakened

Dissociation

a split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others

Psychoactive Drug

a chemical substance that alters perceptions and mood