Sensation and Perception

A set of flashcards focused on key vocabulary related to sensation and perception, useful for understanding psychophysics and the human sensory system.

Sensation

The physical processing of environmental stimuli by the sense organs.

Perception

The psychological process of interpreting sensory information.

Psychophysics

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

Absolute Threshold

The smallest amount of stimulation needed for detection by a sense.

Just Noticeable Difference (JND)

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

Weber's Law

A principle stating that the size of the just noticeable difference is a constant proportion of the original stimulus.

Top-Down Processing

When perceptions are influenced by expectations or prior knowledge.

Bottom-Up Processing

When individual bits of sensory information are processed to construct a more complex message.

Signal Detection Theory

A theory that describes how an individual's response to a stimulus is influenced by sensitivity and decision criteria.

Sensory Adaptation

Diminished sensitivity as a result of constant or recurring stimuli.

Selective Attention

Focusing on one particular task or event, often at the cost of missing other stimuli.

Inattentional Blindness

A failure to perceive objects that are not the focus of attention.

Change Blindness

The failure to detect changes to the visual details of a scene.

Photoreceptors

Cells in the retina that convert light into neural signals; includes rods and cones.

Rods

Photoreceptors in the retina sensitive to dim light and responsible for night vision.

Cones

Photoreceptors in the retina responsible for color vision and detail.

Trichromatic Theory

A theory suggesting that color vision is based on the activity of three different cones sensitive to short, medium, and long wavelengths.

Opponent-Process Theory

A theory that states color perception is controlled by the activity of two opponent systems: red-green and blue-yellow.

Fovea

The area of the retina that contains the highest concentration of cones and is responsible for sharp vision.

Visual Agnosia

An inability to recognize objects despite having normal vision.

Prosopagnosia

An inability to recognize familiar faces.

Monocular Depth Cues

Visual cues that require only one eye to perceive depth, including relative size and linear perspective.

Binocular Depth Cues

Depth cues that require both eyes, such as retinal disparity and convergence.

Auditory System

The part of the sensory system responsible for the sense of hearing.

Sound Localization

The ability to determine the source of a sound in the environment.

Multimodal Integration

The effect that concurrent stimulation in more than one modality has on perception.

McGurk Effect

A phenomenon that demonstrates an interaction between hearing and vision in speech perception.

Synesthesia

A condition where perceptual or cognitive activities trigger exceptional sensory experiences.

Neural Impulses

Electrical signals generated by sensory receptors which transmit information to the brain.

Stimulus

Any external event or object that elicits a sensory response.

Transduction

The process of converting physical energy from stimuli into neural signals.

Ganglion Cells

Cells in the retina that gather information from photoreceptors and send it to the brain via the optic nerve.

Olfactory Bulb

A structure in the brain responsible for processing smells.

Sensation & Perception

Two closely related processes; sensation refers to the detection of stimuli whereas perception refers to the interpretation of those stimuli.

Expectation Effects

Influences on perception based on what an individual expects to experience.

Threshold,

The minimal level of stimulus intensity needed to notice or respond to a stimulus.

Motivation in Perception

Influences that affect perception based on personal motivations or needs.

Fatigue in Perception

How tiredness affects an individual’s ability to accurately perceive stimuli.

Visual Processing Streams

The pathways in the brain that process different aspects of visual information.

Brightness Constancy

The perception that the brightness of an object remains constant despite changes in illumination.

Size Constancy

The perception that an object's size remains constant even when viewed at different distances.