Unit 1.5 AP Pyschology

Sensation

The stimulation of the sense organs.

Perception

Creating meaning from the raw sensory information.

Transduction

The process of converting stimulus energies into neural impulses.

Subliminal messages

Hidden messages targeted at our subconscious mind.

Selective attention

Focusing our awareness on a particular stimulus.

Cocktail party phenomenon

The ability to focus on one conversation despite multiple sounds.

Psychophysics

The study of how physical stimuli are translated into psychological experience.

Threshold

The point at which stimulus intensity is strong enough to be detected.

Absolute threshold

The minimum amount of stimulation a person can detect 50% of the time.

Difference threshold (JND)

The smallest difference in stimulation that a specific sense can detect.

Weber’s Law

The principle that the size of a JND is a constant proportion of the original stimulus.

Signal Detection Theory

Theory that explains how stimuli are detected and how decision processes affect detection.

Hits

Successfully detecting a signal when it is present.

Misses

Failing to detect a signal when it is present.

False alarms

Detecting a signal when it is absent.

Correct rejections

Failing to detect a signal when it is absent.

Setting Criterion

Our expectations and the consequences of detection influence how we respond.

Sensory Adaptation

A gradual decline in sensitivity to prolonged stimulation.

Synesthesia

A condition where one sense is experienced through another.

Light

Electromagnetic radiation that enables vision.

Amplitude

The height of a wave, which determines brightness.

Wavelength

The distance between peaks of a wave, which affects color.

Cornea

The transparent covering that protects the eye.

Pupil

The opening in the iris that allows light to enter the eye.

Iris

The colored part of the eye that regulates pupil size.

Lens

The structure that focuses light onto the retina.

Retina

The layer of photoreceptor cells that absorbs light.

Fovea

The area of the retina responsible for sharp vision.

Rods

Photoreceptors in the retina that are sensitive to light and enable night vision.

Cones

Photoreceptors that detect color and detail in bright light.

Bipolar cells

Cells in the retina that transmit signals from rods and cones to ganglion cells.

Ganglion cells

Cells that form the optic nerve and send visual information to the brain.

Blind spot

The area of the retina where there are no photoreceptors, leading to a gap in visual perception.

Optic nerve

The nerve that carries visual information from the retina to the brain.

Color Theory

Theories that explain how we perceive color.

Trichromatic theory

The theory that color perception is based on three primary colors: red, green, and blue.

Opponent process theory

The theory that color perception is controlled by opposing responses to pairs of colors.

Visual agnosia

A condition where the person can see objects but cannot recognize them.

Prosopagnosia

Inability to recognize faces despite normal vision.

Blindsight

Condition where a person cannot consciously see, but can respond to visual stimuli.

Afterimage

The visual sensation that remains after the stimulus has been removed.

Myopia

Nearsightedness; distant objects appear blurry.

Hyperopia

Farsightedness; close objects appear blurry.

Perceptual Set

The influence of expectations on perceptions.

Feature analysis

The process where the brain breaks down sensory input into basic features.

Bottom-up processing

Building perception from basic sensory input without prior knowledge.

Top-down processing

Interpreting sensory information using prior knowledge and expectations.

Stroop effect

Delay in reaction time when the color of the word interferes with naming the color.

Gestalt Principles

Organizational rules that describe how we perceive wholes rather than parts.

Depth perception

The ability to perceive distance and three-dimensionality.

Retinal disparity

The slight difference in images between our two eyes used to gauge depth.

Convergence

The inward angle of the eyes when looking at near objects.

Linear perspective

The apparent convergence of parallel lines as they recede into the distance.

Texture gradient

The gradual change in texture from coarse to fine as distance increases.

Interposition

When one object overlaps another, causing the overlapped object to appear further away.

Relative clarity

Distant objects appear hazy or less distinct.

Relative size

If two objects are known to be the same size, the smaller one is perceived as further away.

Motion parallax

The apparent movement of stationary objects at different distances during movement.

Perceptual constancy

The perception that objects remain stable despite changes in sensory input.

Pitch

The frequency of a sound wave, determining how high or low a sound seems.

Loudness

The perception of sound intensity, measured in decibels.

Sound localization

The ability to locate the origin of a sound.

Conduction deafness

Hearing loss due to problems with the physical structures of the ear.

Sensorineural deafness

Hearing loss due to damage to hair cells in the inner ear.

Vestibular sense

The sense that provides information about balance and spatial orientation.

Kinesthetic sense

The awareness of the position and movement of body parts.

Taste

The sensory perception of flavor by the tongue.

Smell

The sensory perception of odors detected by the olfactory system.

Supertasters

Individuals who are extremely sensitive to certain tastes, particularly bitter flavors.

Schéma

A mental framework that influences the interpretation of sensory information.

Gate control theory

The theory that pain is controlled by a 'gate' mechanism in the spinal cord.

Pheromones

Chemical signals released by animals that affect social behavior.