Untitled Flashcard Set

Sensation

The process by which sensory receptors and the nervous system receive and represent stimulus energies from the environment.

Perception

The process of organizing and interpreting sensory information to recognize meaningful objects and events.

Sensory Interaction

The principle that one sense may influence another (e.g., smell affects taste).

Transduction

The process of converting one form of energy into neural impulses the brain can interpret.

Psychophysics

The study of relationships between the physical characteristics of stimuli and our psychological experience of them.

Sensory Threshold

The level of stimulation required to detect a stimulus 50% of the time.

Absolute Threshold

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

Difference Threshold (JND - Just Noticeable Difference)

The minimum difference between two stimuli required to detect a change 50% of the time.

Weber's Law

The principle that the just noticeable difference is a constant proportion of the original stimulus.

Subliminal Threshold

Stimuli below one’s absolute threshold for conscious awareness.

Sensory Adaptation

Diminished sensitivity to an unchanging stimulus due to constant exposure.

Signal Detection Theory

Predicts how and when we detect the presence of a faint stimulus, considering psychological factors like expectations, motivation, and alertness.

Perceptual Adaptation

The ability to adjust to changed sensory input (e.g., inverted vision goggles).

Perceptual Set

A mental predisposition to perceive one thing and not another, influenced by expectations and context.

Schema

A mental framework that organizes and interprets information.

Cornea

The clear protective outer layer of the eye that bends light as it enters.

Pupil

The adjustable opening in the center of the eye through which light enters.

Iris

The colored muscle that controls the size of the pupil.

Lens

The transparent structure behind the pupil that changes shape to help focus images on the retina.

Accommodation

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

Retina

The light-sensitive inner surface of the eye containing photoreceptors; site of transduction.

Photoreceptors

Specialized cells (rods and cones) that detect light energy.

Rods

Retinal receptors that detect black, white, and gray; sensitive to dim light; located in the periphery.

Cones

Retinal receptors concentrated in the fovea that detect fine detail and color.

Fovea

The central focal point of the retina with the highest concentration of cones.

Blind Spot

The point where the optic nerve leaves the eye; contains no photoreceptors.

Bipolar Cells

Retinal neurons that receive input from photoreceptors and send signals to ganglion cells.

Ganglion Cells

Retinal neurons whose axons form the optic nerve and transmit signals to the brain.

Feature Detectors

Neurons in the visual cortex that respond to specific features like edges, angles, or movement.

Prosopagnosia

Face blindness; inability to recognize faces.

Blindsight

Ability to respond to visual stimuli without consciously perceiving them.

Parallel Processing

Processing multiple aspects of a stimulus simultaneously (color, motion, form, depth).

Wavelength

Distance between peaks of a light wave; determines color (hue).

Frequency

Number of wave cycles per second; related to wavelength.

Amplitude

Height of a wave; determines brightness (intensity).

Wave Complexity

Determines saturation (purity of color).

Trichromatic Theory (Young-Helmholtz)

The theory that the retina contains three types of cones sensitive to red, green, and blue.

Opponent-Process Theory

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

Afterimage

A visual image that persists after a stimulus is removed.

Dichromatism

Color vision deficiency where only two types of cones function.

Monochromatism

Color blindness where only one type (or none) of cone functions.

Gestalt Principles

Rules by which we organize sensations into meaningful wholes.

Closure

Filling in gaps to create a complete image.

Proximity

Grouping nearby objects together.

Similarity

Grouping objects that are alike.

Continuity

Perceiving smooth, continuous patterns.

Figure-Ground

Organizing the visual field into objects (figure) and background (ground).

Perceptual Constancy

Perceiving objects as unchanging despite changes in light, distance, or angle.

Binocular Cues

Depth cues that require both eyes.

Retinal Disparity

Slight difference between the images seen by each eye; greater disparity = closer object.

Convergence

Inward turning of the eyes when focusing on close objects.

Monocular Cues

Depth cues available to either eye alone.

Linear Perspective

Parallel lines appear to converge with distance.

Relative Clarity

Distant objects appear hazier.

Texture Gradient

Textures become finer and less detailed with distance.

Relative Size

Smaller retinal image is perceived as farther away.

Interposition

When one object blocks another, the blocked object is perceived as farther away.

Stroboscopic Movement

Perception of motion produced by rapid display of still images.

Phi Phenomenon

Illusion of motion created by flashing adjacent lights in succession.

Selective Attention

Focusing conscious awareness on a particular stimulus.

Change Blindness

Failing to notice changes in the environment.

Cocktail Party Effect

Ability to focus on one conversation in a noisy room.

Pitch

Perceived frequency of a sound; high frequency = high pitch.

Timbre

Quality of a sound that distinguishes different sources.

Sound Shadow

Reduction in sound intensity behind the head.

Outer Ear

Collects and funnels sound waves.

Middle Ear

Amplifies vibrations via ossicles.

Inner Ear

Contains cochlea; converts vibrations to neural signals.

Tympanic Membrane

Eardrum; vibrates in response to sound waves.

Ossicles

Three tiny bones (hammer/malleus, anvil/incus, stirrup/stapes) that amplify sound.

Cochlea

Fluid-filled inner ear structure where transduction occurs.

Cilia (Hair Cells)

Sensory receptors that bend and trigger neural impulses.

Frequency Theory

Pitch determined by rate of neural firing matching sound frequency.

Place Theory

Different frequencies stimulate different places along the basilar membrane.

Volley Theory

Groups of neurons fire in rapid succession to encode higher frequencies.

Conductive Hearing Loss

Damage to mechanical system conducting sound to cochlea.

Sensorineural Hearing Loss

Damage to cochlea’s hair cells or auditory nerve.

Cochlear Implant

Electronic device that stimulates auditory nerve directly.

Gate Control Theory

Theory that spinal cord contains a neurological 'gate' that blocks or allows pain signals to pass.

Phantom Limb Syndrome

Sensation of pain or movement in a missing limb.

Homunculus

Visual map of the body’s sensory receptors in the brain.

Kinesthesis

Sense of body position and movement.

Vestibular Sense

Sense of balance and head position; involves semicircular canals and vestibular sacs.

Semicircular Canals

Fluid-filled canals that detect head rotation.

Vestibular Sacs (Utricle & Saccule)

Detect changes in linear movement and head position.

Gustation

Sense of taste; chemicals stimulate taste receptors.

Supertasters

People with heightened taste sensitivity (especially to bitter compounds like PROP).

Nontasters

People with reduced taste sensitivity.

Olfaction

Sense of smell; airborne chemicals stimulate receptors in nasal cavity.

Pheromones

Chemical signals released by organisms that influence behavior of others of the same species.