psych exam 2

Sensation

The process by which important changes in the state of the world create changes in the state of the brain.

Perception

The process by which changes in the state of the brain give rise to our conscious experience of the world.

Constructivism

The idea that the mind actively constructs reality using sensory input expectations and experience.

Realism

The belief that perception directly reflects the external world as it truly is.

Distal senses

Senses that detect information from a distance such as vision audition and olfaction.

Proximal senses

Senses that require direct contact such as touch and taste.

Visual capture

The dominance of vision over other senses in perception.

McGurk effect

A multimodal illusion where visual speech information alters auditory perception.

Transduction

The conversion of physical energy into neural signals.

Sensory adaptation

Reduced sensitivity after prolonged stimulation.

Absolute threshold

The minimum stimulus intensity detected 50 percent of the time.

Difference threshold (JND)

The smallest detectable difference between two stimuli.

Weber’s Law

The JND is a constant proportion of the original stimulus.

Signal Detection Theory

Perception depends on sensitivity and decision criterion.

Change blindness

Failure to notice changes in the environment due to limited attention.

Rods

Photoreceptors for low light no color and peripheral vision.

Cones

Photoreceptors for color detail and daylight vision concentrated in the fovea.

Fovea

The area of the retina with the highest visual acuity.

Retina

The light‑sensitive tissue containing rods and cones.

Optic nerve

The bundle of axons carrying visual information to the brain.

Ventral stream (“what pathway”)

Pathway for object identification damage causes visual form or object agnosia.

Dorsal stream (“where/how pathway”)

Pathway for spatial location and guiding actions damage causes hemispatial neglect or grasping deficits.

Visual form agnosia

Inability to recognize objects despite intact vision caused by ventral stream damage.

Hemispatial neglect

Failure to attend to one side of space caused by dorsal stream damage.

Grasping deficits

Impaired ability to guide actions using vision caused by dorsal stream damage.

Trichromatic theory

Color vision theory proposing three cone types red green and blue.

Opponent‑process theory

Color vision theory involving opposing color pairs red–green blue–yellow black–white.

Gestalt principles

Rules the brain uses to organize sensory input including similarity proximity closure continuity simplicity and common fate.

Perceptual constancy

Perception remains stable despite changes in sensory input such as size shape color and lightness.

Ames room

Illusion showing how expectations distort size perception.

Müller‑Lyer illusion

Illusion where arrowheads alter perceived line length due to experience‑based cues.

Expectancy effects

Perception shaped by what we expect to see or hear.

Monocular cues

Depth cues available to one eye including linear perspective texture gradient interposition relative size and height in plane.

Binocular cues

Depth cues requiring both eyes including retinal disparity and convergence.

Retinal disparity

Difference between the images in each eye used to perceive depth.

Convergence

The inward movement of the eyes when focusing on close objects.

Frequency

The property of sound that determines pitch.

Amplitude

The property of sound that determines loudness.

Timbre

The complexity of a sound wave determining sound quality.

Place code

High‑frequency sounds are encoded by the location of vibration on the cochlea.

Temporal code

Low‑frequency sounds are encoded by the firing rate of auditory neurons.

Olfaction

The sense of smell signals travel directly to the olfactory bulb bypassing the thalamus.

Gustation

The sense of taste including sweet sour salty bitter and umami.

Flavor

The combined perception of taste smell and texture.

Somatosensation

The sense of touch including pressure texture vibration temperature and pain.

A‑delta fibers

Faster sharp pain signals.

C fibers

Slower dull aching pain signals.

Gate Control Theory

Pain signals can be amplified or blocked by the spinal “gate” influenced by emotion attention and expectation.

Kinesthetic sense

The sense of body movement and position.

Vestibular sense

The sense of balance and spatial orientation located in the inner ear.

Multimodal perception

The brain’s integration of information from multiple senses.

Cross‑modal effects

When one sense influences another such as in the McGurk effect.

Synesthesia

A condition where stimulation of one sense triggers an experience in another such as seeing colors when hearing sounds.

Unconditioned Stimulus

Something that naturally causes a response.

Example: Food makes a dog salivate.

Unconditioned Response

The natural reaction to the Unconditional Stimulus.

Example: Salivating when seeing food.

Conditioned Stimulus

A neutral stimulus that becomes meaningful after pairing with the Unconditional Stimulus. Example: A bell that predicts food.

Conditioned Response

The learned reaction to the Conditioned Stimulus. Example: Salivating when hearing the bell.

Cortical Representation

More brain tissue = better sensitivity.
Example: Fingers more accurate than toes.

Classical Conditioning

Learning through association.

Acquisition

Learning the association.

Extinction

Conditioned Stimulus presented without Unconditional Stimulus → Conditional Response weakens.

Spontaneous recovery

Conditional Response returns after rest.