AP PSYCH UNIT 2

Absolute Threshold

The smallest level of stimulus that can be detected by the senses at least 50% of the time.

Just Noticeable Difference (JND)

The minimal change in a stimulus that can be detected.

Transduction

The process of converting sensory stimuli into neural signals that the brain can interpret.

Thalamus

A brain structure that acts as a relay center, sending sensory information (except smell) to appropriate areas of the brain.

Lens

A transparent structure that focuses light on the retina.

Accommodation

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

Retina

The light-sensitive layer of cells at the back of the eye containing rods and cones.

Rods and Cones

Photoreceptor cells; rods detect black, white, and gray, while cones detect color and fine detail.

Blind Spot

The point where the optic nerve exits the eye, creating a spot with no photoreceptors.

Occipital Lobe (Visual Cortex)

The part of the brain responsible for processing visual information.

Opponent-Process Theory

A theory of color vision stating that color is processed in opposing pairs (red-green, blue-yellow, black-white).

Trichromatic Theory

A theory of color vision based on three types of cone cells sensitive to red, green, and blue light.

Light/Dark Adaptation

The ability of the eyes to adjust to changes in light levels.

Prosopagnosia

The inability to recognize faces.

Blindsight

A condition where individuals can respond to visual stimuli without consciously perceiving them.

Hair Cells

Sensory receptors in the cochlea that detect sound vibrations.

Ossicles

Tiny bones in the middle ear (malleus, incus, and stapes) that amplify sound.

Tympanic Membrane

Also known as the eardrum, it vibrates in response to sound waves.

Temporal Lobes (Auditory Cortex)

The brain region responsible for processing auditory information.

Sound Waves

Variations in air pressure that travel as waves, characterized by wavelength and amplitude.

Sound Localization

The ability to determine the location of a sound in space.

Frequency Theory

Suggests that the frequency of auditory nerve impulses corresponds to the frequency of a tone.

Place Theory

Proposes that different areas of the cochlea are activated by different frequencies.

Conduction Deafness

Hearing loss caused by damage to the middle ear structures.

Sensorineural Deafness

Hearing loss caused by damage to the cochlea or auditory nerve.

Phantom Pain

The perception of pain in a limb or part of the body that has been amputated.

Vestibular Sense

The sense of balance and spatial orientation, controlled by semicircular canals in the inner ear.

Kinesthetic Sense

The awareness of the position and movement of body parts.

Cutaneous (Touch) Senses

Sensations of pressure, temperature, and pain perceived through the skin.

Gate-Control Theory

A theory explaining how the nervous system blocks or allows pain signals to pass to the brain.

Anosmia

The inability to perceive odors.

Pheromones

Chemicals secreted by organisms that can influence the behavior or physiology of others.

Taste Buds

Sensory organs that detect taste (sweet, sour, salty, bitter, umami).

Synesthesia

A condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in a second sensory pathway.

Sensation

The process of detecting sensory stimuli from the environment.

Perception

The interpretation and organization of sensory input into meaningful experiences.

Bottom-Up Processing

Analyzing information starting with sensory input and building toward a perception.

Top-Down Processing

Using prior knowledge, experiences, and expectations to interpret sensory input.

Sensory Adaptation

Reduced sensitivity to a stimulus after prolonged exposure.

Inhibition

The brain’s ability to suppress irrelevant sensory information to focus on relevant stimuli.

Monocular Depth Cues

Depth cues that can be perceived using one eye.

Relative Clarity

Objects that are clearer are perceived as closer.

Relative Size

Smaller objects are perceived as farther away if they are assumed to be the same size.

Texture Gradient

Objects with more detail are perceived as closer.

Linear Perspective

Parallel lines appear to converge as they recede into the distance.

Interposition

Closer objects partially block the view of objects farther away.

Binocular Depth Cues

Depth cues that require both eyes.

Retinal Disparity

The difference in images seen by each eye; greater disparity indicates closer objects.

Convergence

The degree to which the eyes turn inward to focus on a nearby object.

Visual Cliff Research

Experiments showing that depth perception is present in infants and other animals.

Perceptual Constancy

The ability to perceive objects as unchanging despite changes in sensory input.

Size Constancy

Perceiving an object as having the same size despite changes in distance.

Shape Constancy

Recognizing an object’s shape regardless of the angle of view.

Color Constancy

Perceiving consistent color under varying lighting conditions.

Gestalt Principles

Psychological rules that describe how we naturally organize sensory information.

Figure-Ground Perception

The ability to distinguish an object (figure) from its background (ground).

Color Afterimages

A visual illusion where a complementary color is seen after staring at a colored image and then looking away.

Reversible Figures

Images that can be interpreted in multiple ways.

Illusions of Movement

Perceptions of motion where none exists.

Sunk Cost Fallacy

Continuing with a decision based on previously invested resources even when it’s irrational to do so.

Framing Effect

The way information is presented affects decisions and judgments.

Confirmation Bias

The tendency to seek out information that supports pre-existing beliefs while ignoring contradictory evidence.

Reliability

The consistency of a test over time and across different administrations.

Test-Retest Reliability

Stability of test scores over time when the same test is administered twice.

Split-Half Reliability

Ensuring consistency within a test by comparing performance on different halves.

Construct Validity

The extent to which a test measures what it claims to measure.

Content Validity

The degree to which a test assesses the intended content or subject matter.

Achievement Tests

Assessments that measure knowledge and skills gained through instruction.

Aptitude Tests

Tests designed to predict future performance or potential in a specific area.

Stereotype Threat

Anxiety or concern that one’s performance may confirm a negative stereotype about their group.