Sensation and Perception Lecture Review

Comprehensive vocabulary flashcards covering sensation, perception, sensory structures, thresholds, and depth cues from Unit 3.

Sensation

The initial pattern of electrical activity that occurs when a stimulus activates receptors.

Perception

The organization of sensory information into meaningful experiences.

Transduction

The transportation of stimuli to the central nervous system (CNS).

Absolute Threshold

The minimum amount of physical energy required to produce a sensation.

Difference Threshold

The minimum amount of physical energy required to produce a change in sensation.

Weber's Law

Principle stating that the larger or stronger the stimulus, the larger the change required for an observer to notice it.

Sensory Adaptation

The process of getting used to ongoing, unchanging stimulation.

Habituation

When the brain stops attending or paying attention to constant, unchanging information.

Signal Detection Theory

The mathematical relationship between motivation, sensitivity, and decision making.

Cornea

The clear membrane that covers the surface of the eye, protecting it and focusing most of the light coming into the eye.

Pupil

The hole in the eye through which light enters.

Iris

The round, colored muscle part of the eye.

Lens

The clear structure behind the iris, suspended by muscle.

Visual Accommodation

The change in thickness of the lens as the eye focuses on objects that are far away or close.

Brightness

The perceived effect of the amplitude of light waves.

Hue

The color dimension determined by wave length, where high wavelength corresponds to purple and low wavelength corresponds to red.

Saturation

The purity of the color that is seen.

Rods

Visual receptors responsible for detecting black and white.

Cones

Visual receptors responsible for detecting color.

Binocular Fusion

The combination of the two images received from each of our two eyes into a single image.

Retinal Disparity

The differences between the two images formed on the retinas.

Stereopsis

The perception of depth resulting from retinal disparity.

Trichromatic Theory

Theory of color vision proposing three types of cones: red, blue, and green.

Opponent-Process Theory

Theory of color vision proposing four primary colors arranged into pairs: red-green and blue-yellow.

Afterimages

Visual sensations that continue to occur after the original stimulus has ceased.

Average Visual Threshold

Being able to see a candle flame from a distance of $30\text{ miles}$ on a dark, calm night.

Microsaccades

Vibrations in the eyes that prevent an image from fading.

Hertz

Waves per second.

Human Hearing Threshold

The ability to hear a watch ticking from a distance of $20\text{ feet}$ away.

Pinna

The visible part of the outer ear.

Auditory Canal

The short tunnel in the outer ear that runs to the eardrum.

Hammer, Anvil, Stirrup

Three little bones in the middle ear that amplify vibrations from the eardrum.

Cochlea

An inner ear structure filled with fluid surrounding the basilar membrane.

Basilar Membrane

A structure in the inner ear that vibrates the Organ of Corti, which sends signals to the auditory nerve.

Place Theory

Auditory theory stating that the pitch we hear depends on where the hair cells are located.

Frequency Theory

Auditory theory stating that pitch is based on how fast the basilar membrane vibrates.

Conduction Hearing Impairment

A hearing impairment where sound vibrations cannot be passed from the eardrum to the cochlea; aided by a hearing aid.

Nerve Hearing Impairment

Damage occurring in the inner ear or nerve pathways to the brain caused by age or loud sounds; can only be helped by a cochlear implant bypassing the outer and middle ear.

Taste Buds

Taste receptors responsible for detecting sour, sweet, bitter, salty, and umami tastes.

Olfactory Receptor Cells

Hairs projecting into the nasal cavity, known as cilia, that send signals to the brain.

Olfactory Bulbs

Structures in the brain located above the sinuses that receive information from olfactory receptor cells.

Vestibular System

A system located inside the inner ear responsible for regulating balance.

Kinesthesis

The sense of movement and body position in relation to the ground, which also assists in perceiving depth.

Visceral Pain

Pain detected in the internal organs.

Somatic Pain

Pain felt in the skin, muscles, tendons, and joints, functioning as a general warning system keeping us from further injury.

Sensory Conflict Theory

Disagreement between visual input and body sensations.

Gestalt

An experience resulting from organizing bits and pieces of sensory information into meaningful experiences via proximity, continuity, similarity, closure, and contiguity.

Contiguity

The Gestalt principle that two things occurring close together are perceived as being related.

Perceptual Inference

The automatic and unconscious process of filling in gaps in what our senses convey to us.

Perceptual Constancy

The tendency to perceive objects in the same way in terms of size, shape, and brightness.

Visual Cliff

An experimental apparatus demonstrating early depth perception, in which $81\%$ of infants at $6\text{ months}$ old refused to crawl over the deep side.

Depth Perception

The ability to see the world in three dimensions.

Monocular Cues

Visual cues used for perceiving depth that require only one eye.

Linear Perspective

A monocular cue where parallel lines appear to converge on each other in the distance.

Relative Size

A monocular cue where an object expected to be a certain size appears smaller, leading the viewer to recognize it as being farther away.

Interposition

A monocular cue based on the assumption that if an object appears to be blocking part of another object, it is in front of it and closer to the viewer.

Aerial Perspective

A monocular cue where haziness surrounding an object causes its distance to be perceived as greater.

Texture Gradient

A monocular cue where textured surfaces appear to become smaller and finer as they recede into the distance.

Binocular Cues

Depth cues that require the use of both eyes.

Convergence

A binocular cue where the eyes rotate inward to look at nearby objects, showing greater inward turning for nearby objects and less for distant objects.

Motion Parallax

The apparent movement of stationary objects relative to each other when walking around or moving one's head from side to side.

Müller-Lyer Illusion

An optical illusion involving line distortion.

Perceptual Set and Expectancy

The tendency to perceive things in a certain way as a result of previous experiences or expectations.

Top-Down Processing

The use of preexisting knowledge to organize individual sensory features.

Bottom-Up Processing

The analysis of smaller sensory features to build up to a complete perceptual experience.

Selective Attention

The ability to focus on one stream of information while other sensory stimuli are present around us.

Cocktail Party Effect

A phenomenon where a specific word catches one's attention even when engaged in a completely different conversation.