Sensation and Perception - Vocabulary Flashcards

Vocabulary-style flashcards covering sensation, perception, and related topics from LO 3.x.

Sensation

Activation of receptors in the sense organs.

Sensory receptors

Specialized neurons that respond to environmental stimuli.

Just noticeable difference (JND)

The smallest detectable difference between two stimuli at 50% detection.

Absolute threshold

The smallest energy needed to consciously detect a stimulus 50% of the time.

Subliminal stimuli

Stimuli below conscious awareness but strong enough to activate receptors.

Subliminal perception

Process by which subliminal stimuli influence the unconscious mind and behavior.

Habituation

Brain’s tendency to stop attending to constant, unchanging information.

Sensory adaptation

Sensory receptors become less responsive to a constant stimulus.

Microsaccades

Tiny eye movements that prevent sensory adaptation to steady input.

Brightness

Perceived intensity of light; determined by the amplitude of the wave.

Color (hue)

Wavelength; long wavelengths are red, short wavelengths are blue.

Saturation

Purity of a color; adding black/gray reduces saturation.

Cornea

Clear outer layer that focuses most of the incoming light.

Pupil

Openings in the iris through which light enters the eye.

Iris

Colored muscle that adjusts pupil size and helps focus the image.

Lens

Clear structure behind the iris that finishes focusing the eye.

Aqueous humor

Clear watery fluid that nourishes the eye.

Vitreous humor

Jelly-like fluid that nourishes the eye and gives it shape.

Retina

Final stop for light in the eye; contains photoreceptors and other cells.

Rods

Photoreceptors for low-light, noncolor vision.

Cones

Photoreceptors for color vision and sharpness in bright light.

Blind spot

Retinal area where the optic nerve exits; lacks photoreceptors.

Photoreceptors

Rods and cones that respond to light.

Visual accommodation

Change in lens thickness to focus on far or near objects.

Ganglion cells

Retinal cells that relay visual information to the brain.

Bipolar cells

Retinal cells between photoreceptors and ganglion cells.

Trichromatic theory

Color vision theory proposing red, blue, and green cones.

Opponent-process theory

Color vision theory with red-green and blue-yellow pairs.

Afterimages

Images that persist briefly after a stimulus is removed.

Color blindness

Difficulty distinguishing colors; can be monochrome or red-green types.

Ishihara test

Color vision test using dot patterns to detect deficiencies.

Wavelength (sound context)

In hearing, related to frequency and pitch of sound waves.

Frequency (sound)

Rate of vibration; perceived as pitch.

Pitch

Perceived frequency of a sound.

Amplitude

Height of a sound wave; relates to loudness.

Hertz (Hz)

Units of frequency (cycles per second).

Auditory canal

Short tunnel from the outer ear to the eardrum.

Tympanic membrane (eardrum)

Thin skin that vibrates when struck by sound waves.

Ossicles

Three middle-ear bones (hammer, anvil, stirrup) that amplify sound.

Cochlea

Fluid-filled inner ear structure where hearing receptors reside.

Organ of Corti

Hair-cell containing structure on the basilar membrane.

Auditory nerve

Nerve fibers that carry auditory signals to the brain.

Place theory

Different pitches are heard by stimulating different locations on the basilar membrane.

Frequency theory

Pitch is determined by the rate of hair cell firing along the membrane.

Volley principle

For high frequencies, groups of neurons fire in turn to code frequency.

Conduction hearing impairment

Damage to the eardrum or middle-ear bones preventing sound conduction.

Nerve (sensorineural) hearing impairment

Damage to inner ear or auditory pathways.

Cochlear implant

Device that converts sound to electrical impulses sent to the cochlea.

Taste buds

Taste receptor cells in the mouth responsible for gustation.

Gustation

Sense of taste.

Five basic tastes

Sweet, sour, salty, bitter, and umami (brothy).

Olfaction

Sense of smell.

Olfactory bulbs

Brain areas that receive information from olfactory receptors.

Olfactory receptors

Receptor cells in the nasal cavity for smell.

Somesthetic senses

Body senses: skin sensations, kinesthetic sense, and vestibular sense.

Gate-control theory

Pain signals must pass through a gating mechanism in the spinal cord.

Kinesthetic sense

Sense of body parts' location and movement.

Proprioceptors

Proprioceptive receptors for kinesthetic sensing.

Vestibular senses

Sensation of movement, balance, and body position.

Perception

Process of organizing and interpreting sensory information.

Size constancy

Perceiving an object as constant in size despite distance changes.

Shape constancy

Perceiving an object's shape as constant despite retinal changes.

Brightness constancy

Perceiving constant brightness despite lighting changes.

Figure-ground

Tendency to perceive objects as figures standing out from the background.

Reversible figures

Figures whose figure-ground arrangement can switch.

Similarity

Objects that look similar are perceived as part of the same group.

Proximity

Objects close to each other are perceived as a group.

Closure

Tendency to complete incomplete figures.

Continuity

Perceiving smooth, continuous patterns rather than broken ones.

Contiguity

Events that occur close in time are linked.

Depth perception

Ability to perceive the world in three dimensions.

Monocular cues (pictorial cues)

Depth cues available to one eye.

Linear perspective

Parallel lines appear to converge with distance.

Relative size

Farther objects appear smaller; interpreted as distance.

Interposition (overlap)

An object blocking another is perceived as closer.

Aerial perspective

Farther objects appear hazier due to atmospheric particles.

Texture gradient

Texture appears finer with distance.

Motion parallax

Nearby objects move faster than distant ones as you move.

Accommodation (depth cue)

Lens changes thickness to focus on near or far objects.

Binocular cues

Depth cues that require both eyes.

Convergence

Eyes rotate inward for near objects; increases as distance decreases.

Binocular disparity

Difference between the two eyes' views; greater for near objects.

Perceptual illusion

Misleading perception of sensory information.

Müller-Lüyer illusion

Line length illusion caused by corner cues in ends of lines.

Moon illusion

Moon appears larger on the horizon due to distance cues.

Phi phenomenon

Sequence of lights appears to move; an illusion of motion.

Autokinetic effect

A stationary light appears to move in darkness.

Stroboscopic motion

Still frames viewed in rapid sequence appear to move.

Rotating snakes

Motion illusion partly due to eye movements.

Ames room illusion

Room designed to distort size perception of people inside.

Perceptual set

Tendency to perceive things a certain way due to expectations.

Top-down processing

Using prior knowledge to organize perception.

Bottom-up processing

Building perception from the smallest features.

Visual cliff

Experiment assessing depth perception using a drop-off surface.