PSYC 101 Ch. 4

Prosopagnosia (Face Blindness)

Inability to detect and identify faces, despite normal object detection.

Stimulus

Anything that can trigger a physical or behavioral change.

Sensation

Simple stimulation of a sense organ.

Perception

Organizing, identifying, and interpreting sensory information.

Bottom-Up Processing

Analysis that begins with sensory receptors and works up to the brain's integration of sensory information.

Top-Down Processing

Information processing guided by higher-level mental processes.

Sensory Adaptation

Diminished sensitivity to constant stimulation.

Psychophysics

Methods that systematically relate the physical characteristics of a stimulus to an observer's perception.

Signal Detection Theory (SDT)

Predicts how and when we detect faint stimuli amid background noise.

Absolute Threshold

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

Difference Threshold (Just Noticeable Difference)

The minimum difference a person can detect between two stimuli 50% of the time.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next.

Amplitude

The amount of energy in a light or sound wave, perceived as brightness.

Purity

The degree to which a light source emits one vs. a mixture of wavelengths.

Rods

Retinal receptors that detect black, white, and gray.

Cones

Retinal receptors that detect fine detail and color.

Photoreceptor Layer

The layer in the retina containing rods and cones that capture light.

Trichromatic Theory

Suggests that color perception results from three types of cones.

Opponent-Process Theory

Suggests that color perception is controlled by opposing activity of three pairs of color receptors.

Feature Detection (V1)

Nerve cells in the brain respond to specific features of stimuli.

Parallel Processing

The brain processes motion, form, depth, and color simultaneously.

Sound Waves

Bands of compressed and expanded air processed by the ears.

Frequency

The number of complete wavelengths that pass a point in a given time.

Intensity

The loudness of sound, measured in decibels (dB).

Timbre

The quality of sound that distinguishes it from other sounds.

Tonotopic Organization

Different parts of the cochlea respond to different frequencies of sound.

Pitch Perception - Place Code

Where in the basilar membrane activity is highest, corresponding to frequency.

Pitch Perception - Temporal Code

The timing of sound waves synchronized with hair cell receptors.

Nociceptors

Sensory receptors that respond to potentially damaging stimuli.

Gate Control Theory

Theory suggesting that pain is regulated by 'gates' in the spinal cord.

Dual Pathways of Pain

Sensory pathway (location) and emotional pathway (feelings about pain).

Proprioception

The sense of bodily position relating tactile sensations to location.

Vestibular Sense

The sense of balance, detected in the inner ear's semicircular canals.

Synesthesia

A condition where one sensory stimulus leads to conscious processing of another.

Sensory Interaction

The phenomenon where different sensory systems influence each other.

Taste

A chemical sense with receptors for sweet, salty, sour, bitter, and umami.

Olfaction

The sense of smell, processed by the olfactory system, bypassing the thalamus.

Figure-Ground

The organization of the visual field into objects standing out from their background.

Grouping

The perceptual tendency to organize stimuli into meaningful groups.

Depth Perception

The ability to judge the distance of objects.

Motion Perception - Phi Phenomenon

An illusion of movement created by blinking lights.

Perceptual Constancies

The tendency to perceive objects as unchanging despite changes in illumination.

Inattentional Blindness

Failure to notice something unexpected due to focused attention elsewhere.

Change Blindness

Failure to detect changes between what is currently present and what was present a moment ago.

Attentional Blink

The phenomenon where one becomes 'blind' to stimuli after identifying a previous one.

Subliminal Perception

The processing of stimuli below the threshold of conscious awareness.

Absolute Threshold

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

Difference Threshold

The minimum difference a person can detect between two stimuli 50% of the time.