Psychology Ch. 3: Sensation and Perception

Sensation

Sensation

The process of detecting physical energy from the environment and coding it into neural signals.

Perception

The way our brain selects, organizes, and interprets sensory information.

Receptor cells

Cells stimulated by energy that create sensation.

Sensory neurons

Neurons that carry information to the brain as coded signals.

Transduction

The process of converting physical energy into an electrical charge.

Sensory thresholds

The limits of what we can detect in our environment.

Psychophysics

The study of the relationship between physical characteristics of stimuli and sensory experiences.

Absolute threshold

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

Difference threshold

The minimum difference between two stimuli needed to detect a difference at least 50% of the time.

Weber’s Law

The principle that the difference between two objects varies proportionally to the initial size of the stimulus.

Signal detection theory

A theory explaining how varying circumstances affect people's responses to stimuli.

Subliminal perception

Sensation that occurs below our absolute threshold.

Subliminal persuasion

Using subliminal techniques to influence behavior.

Sensory adaptation

The process where our senses become less responsive to unchanging stimuli.

Wavelengths

The distance between the peaks of energy waves, determining color in vision.

Cornea

The eye's protective cover that first contacts light.

Retina

The back of the eye that converts light stimuli into neural communication.

Rods

Photoreceptors that respond to varying degrees of light and dark.

Cones

Photoreceptors that allow us to see color and work best in bright light.

Blind spot

The area in the eye where the optic nerve exits and has no receptor cells.

Optic chiasm

The point where optic nerves cross over before reaching the brain.

Feature detector neurons

Neurons that respond to specific features in the visual field.

Trichromatic theory

The theory that three types of cones are sensitive to different wavelengths of light.

Opponent Process Theory

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

Sound wave

A change in air pressure caused by the movement of air/fluid molecules.

Frequency

Determines the pitch of a sound, measured in Hertz (Hz).

Amplitude

Determines the volume of a sound, measured in decibels (dB).

Cochlea

The inner ear structure that contains fluid and hair cells for hearing.

Place theory

The theory that different pitches activate different sets of hair cells in the cochlea.

Frequency theory

The theory that lower pitches are perceived based on the firing rate of neurons.

Sensorineural hearing loss

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

Conductive hearing loss

Hearing loss due to problems in the outer or middle ear.

Olfaction

The ability to smell odors.

Taste buds

Sensory receptors on the tongue that detect taste.

Five basic tastes

Sweet, salty, sour, bitter, and umami.

Kinesthetic sense

The sense that provides information about body position and movement.

Proprioceptors

Specialized nerve endings that provide information about body parts' positions.

Vestibular sense

The sense that monitors the body's position in space and helps maintain balance.

Bottom-up processing

Processing that starts with raw data and sends it to the brain for interpretation.

Top-down processing

Processing that relies on previous knowledge and experience to influence perceptions.

Perceptual constancy

The perception of a stimulus remains the same despite changes in its characteristics.

Gestalt principles

The principles that describe how we naturally group objects together.

Depth perception

The ability to judge distances and see objects in three dimensions.

Monocular cues

Depth cues that can be perceived with one eye.

Binocular cues

Depth cues that require both eyes for perception.

Perceptual illusions

Instances where the appearance of a stimulus differs from its actual nature.

Literal visual illusions

Illusions that occur before light enters the eye.

Physiological illusions

Illusions caused by excessive stimulation to the eyes or brain.

Cognitive illusions

Illusions that involve high-order thinking and interaction between sensory and perceptual systems.