AP PSYCH - Sensations & Perceptions (Unit 4)

Sensation

Sensation

Process where sensory receptors and nervous systems take in stimulus from environment

Perception

Process of organizing and interpreting sensory info letting us remember/recognize meaningful things

Nociceptors

sensory receptors that enable the perception of pain in response to potentially harmful stimuli

Bottom-Up Processing

Analysis that begins with basic senses and then works up to brain's interpretation

Top-Down Processing

Where we process info with higher thinking. We construct perceptions based on experience and expectations

Selective Attention

When you focus on one particular thing/stimuli

Inattentional Blindness

When we can't see visible objects because our attention is elsewhere

Change Blindness

Failing to notice changes in environment

Psychophysics

Study of relationships between the physical characteristics of stimuli (e.g. intensity and our psychological experience of them)

Absolute Threshold

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

Signal Detection Theory

Theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes that there's no absolute threshold

Subliminal

Hidden from our consciousness; below absolute threshold

Priming

Unconscious associations

Difference Threshold

Minimum difference between two stimuli required for detection. 50% of the time it's a just noticeable difference

Weber's Law

Principle that, to be perceived as different, two stimuli must differ by a constant percentage

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation

Transduction

Conversion of one form of energy to another. In sensation, it's transforming stimulus energy (sights, sounds, smells) into neural impulses our brain can interpret

Wavelength

Distance from one peak of a wave to another

Hue

Dimension of color that is determined by the wavelength of light

Intensity

Amount of energy in a light or sound wave; determined by amplitude.

Pupil

Adjustable opening in center of eye where light enters

Iris

Ring of muscle tissue that is the color part of the eye. Controls pupil opening size

Lens

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

Retina

Light-sensitive inner surface of eye that contains receptor rods, cones, and layers of neurons that begin processing of visual info

Accommodation

Process in which the lens changes shape to focus near or far objects on the retina

Optic Nerve

Nerve that carries neural impulses from eye to the brain

Rods

Retinal receptor that detect black, white, and grey. Necessary for peripheral and twilight vision when cones don't work that well or respond

Cones

Retinal receptor close to the center of the retina. Works best at daylight or in well lit place. Finds fine details and color

Blind Spot

Point where optic nerve leaves the eye, creating an area where you can't see There are no receptors located in this spot

Fovea

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 angle, shape, and movement

Parallel Processing

The processing of many aspects of a problem simultaneously. Brain's natural mode of information processing for many functions

Young-Helmholtz Trichromatic (3-color) Theory

Theory that retina has 3 color receptors: red, blue, and green. Theory states that, when combined, they can make any color

Opponent Process Theory

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

Audition

Sense or act of hearing

Amplitude

Height of a wave

Amplitude; loudness

The _________ of sound waves determines their ________

Frequency

Number of complete wavelengths that pass a point in a given time (e.g. three things a second)

Pitch

Tone's experienced highness or lowness. Depends on frequency. Long waves produce a low sound. Short waves produce a high sound

Decibels

A unit of measurement of loudness

Middle Ear

Chamber between the eardrum and cochlea that has three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on a cochlea's oval window

Cochlea

Coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

Inner Ear

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

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 travelling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch

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 receptor cells or to the auditory nerves. Nerve deafness

Cochlear Implant

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

Kinesthesis

System for sensing the position and movement of body parts

Vestibular Sense

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

Gate-Control Theory

Theory that spinal cord has a neurological "gate" that either allows or blocks pain signals to the brain

Sensory Interaction

Principle that one sense may influence another

Gestalt

An organized whole

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

Depth Perception

The ability to see objects in 3D although the images that hit the retina are 2D. It allow us to judge distance

Visual Cliff

A lab device for testing depth perception in babies and young animals

Binocular Cues

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

Retinal Disparity

Binocular cue for perceiving depth: the difference between the two images. Greater this is, the closer the object

Monocular Cues

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

Phi Phenomenon

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 (seeing the open door as a rectangle even though it looks like a trapezoid or something)

Color Constancy

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

Perceptual Adaptation

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

Perceptual Set

Mental predisposition to perceive one thing and not another

ESP

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

Parapsychology

Study of paranormal phenomena, including ESP and Psychokinesis

Gestalt Psychology

Led by Max Wertheimer, this early psychology school of thought focused not on how we feel, but on how we experience the world. How humans always look for some kind of pattern in everyday things. Where the saying "the whole is greater than the some of the parts" originates from. Some principles of Gestalt include: Closure, Proximity, and Continuation.

Closure (Gestalt)

the tendency to complete figures that are incomplete

Proximity (Gestalt)

objects that are close together are more likely to be perceived as belonging in the same group

Continuation (Gestalt)

Perception of a continuous line through a small break.

Viewers perceive implied lines that carry smoothly from one element to the next.

Figure and Ground (Gestalt)

we perceive any object, called the FIGURE, as distinct from its surroundings, called the GROUND

Similarity (Gestalt)

Objects that are similar in appearance are more likely to be perceived as belonging in the same group.

Symmetry & Order (Gestalt)

Viewers look for a sense of balance and order in design and composition. We tend to close symmetrical forms to make a single shape or object.