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 (stimulus 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.

👁 Vision Terms

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).

🌈 Color Vision

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.

👀 Perceptual Organization

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.

📏 Depth Perception

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.

👂 Hearing

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.

✋ Touch & Body Senses

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.

👅 Taste & Smell

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.