Unit 4 ap psych

Sensation

The process by which our sensory receptors and nervous systems 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 sensory 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

Examples of selective attention:

Cocktail Party Effect, the flow experience, distracted driving impairing attention

The Cocktail Party Effect

Ability to attend to one voice among many

The Flow Experience

Being caught up in an experience and missing out on obvious environmental stimuli

Selective Inattention

A level of conscious awareness in which we are blind to all but a tiny sliver of all visual stimuli

Examples of Selective Inattention

Inattentional blindness, change blindness/deafness, choice blindness, pop-out

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere

Change Blindness/Deafness

Failing to notice changes in the environment

Choice Blindness

Making choices with only a limited amount of information

Pop-Out

A moment during which we are "popped" back into our conscious awareness

Psychophysics

The study of relationships between the physical characteristics of stimuli and our psychological experience of them- thresholds fall under this area of science

Absolute Threshold

The minimum stimulation needed to detect a particular stimulus 50 percent of the time- developed by Gustav Fechner

Fechner's Methods of Measuring Noticeable Difference

Method of Limits, Method of Right and Wrong Cases, Method of Adjustment

Method of Limits

Begins with minimal stimulus, gradually increased until subject perceives it

Method of Right and Wrong Cases

Subject presented with identical stimuli and slight changes are made, which the subject must identify

Method of Adjustment

Two stimuli presented, one adjusted to be exactly like the other, the average amount of errors is computed

Signal Detection Theory

A theory predicting how and when we detect the presence of a faint stimuli (signal) amid background stimulation (noise); assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, and motivations

Subliminal Stimulation

Below one's absolute threshold for conscious awareness

Priming

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

Difference Threshold (Just Noticeable Difference, jnd)

The minimum difference between two stimuli required for detection 50 percent of the time

Weber's Law

To be perceived as different, two stimuli must differ by a constant percentage (rather than by a constant amount)

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation

Transduction

The 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

Wavelength

The distance from the peak of one light or sound wave to the peak of the next- determines a wave's hue and quality

Hue

The dimension of color that is determined by the wavelength of light; what we know as the color names (blue, green, etc.)

Intensity

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

How the Eye Transforms Light Energy into Neural Messages

Light enters through cornea, passes through pupil (surrounded by iris), lens focuses light rays into an upside down image on the retina, receptor cells convert light energy into neural impulses which are forwarded through the optic nerve to the brain's visual cortex

Cornea

Protects the eye and bends light to provide focus

Pupil

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

Iris

A ring of muscle tissues that forms the colored section of the eye 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 through accommodation

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

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 retinal (fovea) and that function in daylight or in well-light conditions; detect fine detail and give rise to color sensations

Fovea

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

Optic Nerve

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

Bind Spot

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

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 many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision

Young-Helmholtz Trichromatic Theory

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 a combination, can produce the perception of any color

Opponent Process Theory

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

Amplitude

Strength of sound waves, determines loudness

Frequency

The number of complete wavelengths that pass a point in a given time; determines pitch

Pitch

A tone's experienced highness or lowness; determined by frequency

Decibels

Unit of measure for sound

Outer Ear

Channels sound waves through the auditory canal to the eardrum

Eardrum

A tight membrane that vibrates with the waves

Middle Ear

The chamber between the eardrum and the cochlea containing the ossicles that concentrate the vibrations of the eardrum on the cochlea's oval window

Ossicles

Part of the middle ear; three tiny bones (malleus, incus, and stapes) that transmit vibrations of the eardrum

Inner Ear

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

Cochlea

Part of the inner ear; a coiled, fluid-filled tube through which sound waves trigger nerve impulses

Oval Window

The cochlea's membrane

Basilar Membrane

Surface lined in highly sensitive hair cells

Auditory Nerve

Sends neural images, via the thalamus, to the temporal lobe's auditory cortex

Pathway of a Sound

Sound waves channeled through auditory canal to eardrum, middle ear (ossicles) transmits the vibrations, which pass to the cochlea. The oval window vibrates, moving the fluid that fills the cochlea; the motion causes ripples in the basilar membrane, which bends its hair cells. The hair cell movement triggers neural impulses, which are sent to the temporal lobe's auditory cortex by the auditory nerve, via the thalamus

Hair Cell Damage

Accounts for most hearing loss

Loudness

Interpreted from the number of activated hair cells

Hermann von Helmholtz's Place Theory

Links the pitch we hear with the place where the cochlea's basilar membrane is stimulated; the brain determines the sounds's pitch by recognizing the specific place on the membrane that is generating the neural signal; cannot explain how we hear low-pitched sounds

Frequency Theory

Rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense pitch; explains how we hear low-pitched sounds

Sound on the Right Side

Right ear receives a more intense sound slightly sooner than the left ear

Sound on the Left Side

Left ear receives a more intense sound slightly sooner than the right ear

Sound Behind, Overhead, or Beneath

Harder to locate than sounds on immediate sides because the sound strikes both ears simultaneously

Basic Sound Wave Path

Auditory canal and eardrum to bones of the middle ear to the cochlea to the hair cells to the thalamus and temporal lobes to the auditory cortex

Conduction Hearing Loss

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

Sensorineural Hearing Loss

Hearing loss caused by damage to the cochlea's hair receptor cells or to the auditory nerves; a.k.a nerve deafness

Cochlear Implant

A device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea; best implanted at a very early age

Touch

This sense is essential to development; very distinct, with different types of nerve endings within the skin (pressure, warmth, coldness, pain)

Skin

The largest organ in the body

Hairy Skin

Contains hair cells, which detect movement and pressure

Glabrous Skin

Contains no hair cells; receptors are very sensitive (palms, lips, bottoms of feet)

Pressure

Only feeling with identifiable specialized nerve endings

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

Sense of Balance

Maintained by the inner ear: semicircular canals, vestibular sacs, and cochlea (contains fluid that moves when your head moves). Movement stimulates hair receptors, which send messages to the cerebellum, enabling you to maintain balance and a sense of body position

Pain

The body's way of telling you that something is wrong

Nociceptors

Sensory receptors that detect hurtful temperatures, pressures, or chemicals

Melzack and Wall's Gate Control Theory

The theory that the spinal cord contains a neurological "gate" that blocks pain signals to 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 closed by activity in larger fibers or by information coming from the brain

3 Subtypes of People Evaluated at Pain Centers

Dysfunctional, interpersonally distressed, and adaptive copers; developed by Dennis Turk

Dysfunctional Pain Patients

High levels of pain and psychological distress, believe that they have little control over their lives and are inactive

Interpersonally Distressed Pain Patients

Feel that they have little social support and that others do not take their pain seriously

Adaptive Coper Pain Patients

Report far less pain and social distress than do those in other subtypes and continue to function at relatively high levels

Sensations of Tase

Sour, sweet, salty, bitter, umami; a chemical sense

Umami

Meaty taste

Process of Tasting

Each bump on the tongue has 200+ taste buds; each bud has a pre that catches food chemicals; each pore has 50-100 taste receptor cells projecting hairs that sense food molecules and alert the brain's temporal lobe

Taste Receptors

Many inside each pore in taste buds; reproduce themselves every few weeks

Sensory Interaction

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

Process of Smelling

Molecules of a substance carried in the air reach a cluster of 5 million+ olfactory receptor cells at the top of each nasal cavity, which respond selectively and alert the brain through their axon fibers; bypass the thalamus

Odor Molecules

Come in many shapes and sizes; different olfactory receptors in the nasal cavity detect them

Smell

Sense associated remarkably well with memories and emotions

Prefrontal Cortex

Cortex near which smells are processed; works with the limbic system to process emotional memories

Gestalt

An organized whole

Gestalt Psychologists

Emphasize our tendency to integrate pieces of information into meaningful wholes

Figure-Ground

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

Grouping

The (Gestalt) perceptual tendency to organize stimuli into coherent groups; includes proximity, similarity, continuity, connectedness, and closure

Proximity

We group near by figures together; grouping/Gestalt rule