AP Psychology: Unit #4 Sensation & Perception

Absolute threshold

Minimum stimulation needed to detect a particular stimulus 50% of the time.

Acuity

ability to detect fine details; sharpness of vision. Can be affected by small distortions in the shape of the eye

Amplitude

The maximum extent of a vibration or oscillation, measured from the position of equilibrium

Attention

the set of process from which you choose among the various stimuli bombarding your senses at any instant, allowing some to be further processed by your senses and brain

Audition

the sense of hearing. The loudness of a sound is determined by the amplitude or height of the sound wave

bottom-up processing

Based upon properties of the stimulus (e.g., patterns of light & dark areas); Process this way when we have NO prior knowledge, start at bottom and work our way up; (E.g. eating something new, Touchy Feely)

Change Blindness

Failing to notice changes in the environment

Cocktail Party Effect

The ability to attend selectively to one voice among many UNTIL you hear your name or the name of someone close to you

Conduction Hearing Loss

occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles).

cones

A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides color vision and sharp central vision.

Difference threshold

the smallest amount by which two sensory stimuli can differ in order for an individual to perceive them as different; also known as Just Noticeable Difference (JND).

Frequency

the number of complete waves that pass a given point in space every second

Gate-control theory

pain is experienced only if the pain messages can pass through a gate in the spinal cord on their route to the brain. The gate is opened by small nerve fiber that carry pain signals and closed by neural activity of larger nerve fibers, which conduct most other sensory signals, or by information coming from the brain

Gustation

the chemical sense of taste with receptors cells in the taste bud in fungiform papillae on the tongue, on the roof of the mouth, and in the throat. Molecules must dissolve to be sensed. The five basic taste sensation are sweet, sour, salty, bitter, and, newly added to the list, umami or glutamate. Flavor is the interaction of sensation of taste and odor with contributions by temperature, etc.

Hue

A color or shade

Illusion

a perception, as of visual stimuli (optical illusion) that represents what is perceived in a way different from the way it is in reality.

intensity

refers to light and sound waves, and is defined as the amount of energy in a light or sound wave.

Kinesthesis

body sense that provides information about the position and movement of individuals parts of your body with receptor in muscles, tendons, and joints

Olfaction

The sense of smell of with the receptors in the mucous membrane on the roof of the nasal cavity. Molecules must reach the membrane and dissolve to be sensed. Olfactory receptors synapse immediately with neurons of the olfactory bulbs in the brain with no pathways to the thalamus and cones

Opponent-process theory

proposed mechanism for color vision with opposing retinal process for red-green, yellow-blue, white-black. Some retinal cells are stimulated by one of a pair in inhibited by the other

Parallel Processing

The ability for the brain to process many things at once; color, depth, form and movement.

Perception

is the way we interpret these sensations and therefore make sense of everything around us. (Create MEANING)

Perceptual Adaptation

the ability of the body to adapt to an environment by tuning out distractions; in vision you could wear the goggles and adjust your vision

Photoreceptors

modified neurons that convert light energy to electrochemical neural impulses

Pitch

the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone.

Place Theory

is a theory of hearing pitch determined by point of maximum vibration (place) on basilar membrane; Helps explain how we hear HIGH pitch sounds

Frequency Theory

is a theory of hearing pitch determined by the rate at which the hair cells fire; Helps explain how we hear LOW pitch sounds

Priming

the unconscious activation of certain associations which predisposes memories, thoughts or responses (Spell the word SHOP, ..S-H-O-P, what do you do at a green light?)

Psychophysics

A study of the relationship between physical characteristics of stimuli and our psychological experience with them; concerned mostly with physical attributes of the stimulus; oldest form of Psychology; Gustav Fechner is the Father of this.

Rods

are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells.

Selective Attention

the process by which a person can selectively pick out one message from a mixture of messages occurring simultaneously

Sensation

refers to the process of sensing raw data in our environment through touch, taste, sound, sight and smell. (Encoding)

Sensorineural Hearing Loss

is a type of hearing loss, or deafness, in which the root cause lies in the inner ear (cochlea and associated structures), vestibulocochlear nerve (cranial nerve VIII), or central auditory processing centers of the brain.

Sensory Adaption

The process in which changes in the sensitivity of sensory receptors occur in relation to the stimulus

Sensory Interaction

this is the principle that one sense can influence another. Smell influences taste.

signal detection theory

Predicts how and when we detect the presence of a faint stimulus (signal) amid background noise (other stimulation). This assumes that there is no single absolute threshold and detection depends on: a person's experience, expectations, motivation and level of fatigue

Somatosensation

the skin: touch/pressure, temperature and pain

Stroboscopic Effect

visual phenomenon that makes moving objects appear still when viewed in discrete series of short or instantaneous as distinct from a continuous view.

Subliminal Threshold

When stimuli are below one's absolute threshold for conscious awareness.

top down processing

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

Phototransduction

In vision, the process of converting one form of energy into another; changing physical energy into electrical signals (neural impulses) that can make their way to the brain.

Vestibular sense

body sense of equilibrium with hair like receptors in semicircular canals and vestibular sac in the inner ear

Semicircular canals

Organs in the inner ear used in sensing body orientation and balance (vestibular sense); Relies on fluid in the canals; Spinning in circles disrupts the fluid

Wavelength Light Characteristics

is the distance from the peak of one wave to the peak of the next; short wavelengths \= high, bluish colors; long, reddish colors

Frequency (Pitch) Sound Characteristics

Short wavelengths \= high frequency; high pitched sounds; Long wavelengths \= low frequency, low pitched sounds.

Decibels

the measure of sound intensity.

Weber's Laws

The rule for difference threshold, "Regardless of magnitude, two stimuli must differ by a constant proportion/% for the difference to be noticeable."

Trichromatic Theory of Color

Also known as the Young-Helmholz Theory of Color; Human eye has 3 types of cone receptors sensitive to different; People see colors because the eye does its own "color mixing" (blue/short; green/medium; red/long)

Pupil

hole that allows light to enter the eye

Lens

Expands and contracts - changes size and thickness; Focuses light on the retina; "accommodates"

Iris

Colored muscle that controls (pupil) how much light enters eye

Cornea

Transparent outer cover of eye, protects eye

Retina

Contains visual sensory receptors, the rods and cones and is the entire back of eye; believed to be the third brain

Fovea

Central point in the retina around which the eye's cones cluster.

Optic Nerve

Created from the ganglion cells and carries neural impulses from the eye to the thalamus to the visual cortex.

Blind Spot

Point where the optic nerve leaves the eye because there are no receptor cells located there.

Accommodation

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

Nearsightedness

Also known as Myopia; a condition in which nearby objects are seen more clearly than distant objects; focus is in FRONT of retina

Farsightedness

Also known as Hyperopia; a condition in which faraway objects are seen more clearly than near objects; focus is in BACK of retina

Bipolar Cells

receive messages from photoreceptors (rods & cones) and transmit them to ganglion cells

Ganglion Cells

receive messages from the bipolar cells and converge to form the optic nerve

Feature detectors

Nerve cells in the visual cortex respond to specific features, such as edges, angles, and movement.

Hubel & Wiesel's Experiment

Their experiment one them the Nobel Peace Prize in 1981, as they had inserted microscopic electrodes into the visual cortex of experimental animals to read the activity of single cells in the visual cortex while presenting various stimuli to the animal's eyes. They found a topographical mapping in the cortex, i.e. that nearby cells in the cortex represented nearby regions in the visual field, i.e. that the visual cortex represents a spatial map of the visual field.

Color Blindness

Deficiencies in color receptors (cones), ganglia, optic nerve, or occipital lobe may result in color blindness; Ishihara Test

Echolocation

The general method of locating objects by returning sounds waves.

Pinna

Very outer part of the ear that one can physically touch.

Sound Waves

is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water.

Auditory Canal

is a tube running from the outer ear to the middle ear.

Hammer, Anvil, Stirrup

The three tiny bones that transfer sound waves from the Eardrum to the Cochlea

Ossicles

Three tiny bones that transfer sound waves from the Eardrum to the Cochlea; hammer, anvil & stirrup

Oval Window

The point on the surface of the cochlea which receives the sound vibration from the ossicles.

Cochlea

The major organ of hearing; Coiled, bony, fluid-filled tube in the inner ear that transforms (transduction) sound vibrations to auditory signals

Eardrum

Also known as the Tympanic Membrane; The tissue barrier that transfers sound vibration from the air to the tiny bones of the middle ear; can be damaged by objects in the ear or exceptionally loud noises

Basilar Membrane

within the cochlea of the inner ear separates two liquid filled tubes that run along the coil of the cochlea and contains tiny hair cells.

Auditory Nerve

Carries sound information from the ears to the thalamus and then the temporal lobes of the brain.

Cilia

Also known as hair cells; the receptor cells for hearing located in the cochlea; Responsible for changing sound vibrations into neural impulses

Sound localization

Because we have two ears, sounds that reach one ear faster than the other ear cause us to know where the sound is coming from.

Inattentional blindness

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

Visual Capture

the tendency for vision to dominate the other senses.

Gestalt

an organized whole; tendency to fill in the blanks and see the "whole picture"

Figure-Ground

the organization of the visual field into objects that stand out from their surroundings, determine what is the background and what is the image

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. Experiment asks "Will infants walk off a cliff or do they realize they are at the edge?"

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 closer the object.

Convergence

a binocular cue for perceiving depth; the extent to which the eyes converge inward when looking at an object. the greater the inward strain, the closer the object. Each eye sees the image and the two images converge into one.

Phi Phenomenon

An illusion of movement that is made when two or more adjacent lights blink on and off in quick succession and we perceive it as one light moving back and forth between them

Perceptual Constancy

perceiving objects as unchanging (having consistent lightness, color, shape, and size) even as illumination and retinal images change

Perceptual Set

a mental predisposition to perceive one thing and not another.

Human Factor Psychology

a branch of psychology that explores how people and machines interact and how machines and physical environments can be made safe and easy to use.

Extrasensory Perception (ESP)

the controversial claim that perception can occur apart from sensory input. Said to include telepathy, clairvoyance, and precognition.

Grouping

the perceptual tendency to organize stimuli into coherent groups. We tend to group similar objects together.

Proximity

We group nearby figures together

Similarity

We group together figures similar to each other

Continuity

We perceive smooth, continuous patterns rather than discontinuous ones.

Connectedness

When they are uniform and linked, we perceive spots,lines,or ares as a single unit

Closure

We fill in gaps to create a complete, whole object.

Monocular Cues

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

Relative size

A monocular cue to perceive the smaller retinal image as farther away

Interposition

A monocular cue for if one object partially blocks our view of another, we perceive it as closer