Sensation & Perception

These flashcards cover the key concepts from the lecture on sensation and perception.

Sensation

The detection of external physical stimulus by the sense organs and the transmission of information about this stimulus to the brain.

Perception

The processing, organization, and interpretation of sensory information in the brain that results in an internal neural representation of a physical stimulus.

Sensory receptors

Sensory organs that detect physical stimulation from the external world and convert that stimulation into information that can be processed by the brain.

Transduction

The process by which sensory receptors change physical stimuli into signals that are eventually sent to the brain.

Absolute threshold

The smallest amount of physical stimulation required to detect a sensory input 50% of the time.

Difference threshold

The minimum difference in physical stimulation required to detect a difference between two sensory inputs.

Weber's Law

The principle that the just-noticeable difference between two sensory inputs is based on a proportion of the original sensory input.

Sensory adaptation

A decrease in sensitivity to a constant level of stimulation.

Rod

A type of visual receptor that responds best to low levels of illumination and does not support color vision or detection of fine detail.

Cone

A type of visual receptor that responds best to higher levels of illumination and is responsible for color vision and detection of fine detail.

Fovea

A small region near the center of the retina where cones are densely packed.

Trichromatic theory

The theory that there are three types of cone receptor cells in the retina responsible for color perception.

Opponent-process theory

The theory that ganglion cells in the retina receive excitatory input from one type of cone and inhibitory input from another, creating the perception of opposing colors.

Bottom-up processing

The perception of objects based on analysis of environmental stimulus input by sensory receptors.

Top-down processing

The perception of objects based on prior experiences and expectations that influence how sensory receptors process stimulus input.

Gestalt principles

The visual system’s organization of features and regions to create the perception of a whole, unified object.

Gustation

The sense of taste.

Olfactory epithelium

A tissue layer in the nasal cavity containing olfactory receptors that produce information processed in the brain as smell.

Gustatory cortex

The area of the brain that processes perception of taste.

Pain receptors

Sensory receptors that detect painful stimuli; can be classified into fast fibers and slow fibers.

Spinal reflex

Automatic involuntary responses to stimuli controlled at the level of the spinal cord.