Sensation and Perception

Signal detection theory

Perception results from both sensory information and making a judgment.

Response bias

A person’s readiness to report detecting a stimulus.

Hits

A stimulus that activates a sensory receptor.

Misses

A failure to detect a stimulus that is present.

False alarms

Incorrect identifications of a stimulus that is not present.

Correct rejections

When a participant correctly identifies a stimulus as absent.

Factors affecting response bias

Factors like expectations, motivation, and the context of the situation.

Expectations

Influence how we perceive the world.

Motivation

The force that propels goal-directed behavior.

Gestalt approach

We perceive objects as a whole rather than as a sum of the individual parts.

Figure ground perception

The inherent distinction between an object and its background.

Grouping principles

Principles that help us organize sensory information into meaningful patterns.

Proximity

The tendency to group objects together that are close to each other.

Similarity

The tendency to perceive things that share common features as belonging together.

Continuity

The tendency to perceive a continuous pattern even when it is interrupted.

Closure

The tendency to perceive incomplete figures as complete.

Perceptual constancy

The tendency to perceive objects as stable and unchanging despite changes in sensory input.

Color constancy

Consistent perception of color of objects although the amount of light changes.

Lightness constancy

Consistent perception of shade of objects although the amount of light changes.

Shape constancy

Perception that an object’s shape remains constant despite changing shape of retinal image.

Size constancy

Perception that the size of objects remains constant despite different sizes of images on the retina.