Chapter 4 Notes

Sensation

Physical stimulation of sensory receptors.

Perception

Interpretation of sensory stimulus.

Bottom up processing

Information processing that begins with sensory input and leads to action.

Transduction

The process of converting energy into electrochemical energy.

Photoreception

Vision; the detection of light.

Mechanoreception

Detection of pressure, vibration, and movement; related to touch and hearing.

Chemoreception

Detection of chemical stimuli; related to smell and taste.

Absolute threshold

Minimum amount of energy detectable in an environment.

Difference threshold

Minimum amount of change in stimulus that is detectable.

Signal Detection Theory (SDT)

A framework for measuring perceptual sensitivity apart from decision-making style.

Sensory Adaptation

Gradual decline in sensitivity to prolonged stimulation.

Trichromatic Theory

Theory that explains color vision through three types of cones: red, green, and blue.

Gestalt Psychology

A psychological approach that emphasizes the organization of sensations into meaningful wholes.

Figure-ground organization

The ability to distinguish an object from its background.

Size Constancy

Perception that objects maintain a constant size despite changes in distance.

Shape Constancy

Perception that the form of a familiar object is constant, even with changing images.

Color Constancy

Perceiving familiar objects as having a consistent color despite changes in lighting.

Selective Attention

Focusing awareness on a narrowed aspect of the environment.

Change blindness

Failure to notice changes in a visual scene.

Just noticeable difference (JND)

The smallest detectable difference between two stimuli 50% of the time.

Noise

Irrelevant or competing stimuli.

After image

A visual illusion in which the color is perceived after the original stimulus has been removed.