COG-PSY, CH 2

Sensation

The process of absorbing raw physical energy through sensory receptors such as eyes and ears.

Perception

The process of selecting, organizing, and interpreting neural signals.

Transduction

The conversion of raw energy from sense receptors into neural signals sent to the brain.

Absolute Thresholds

The smallest detectable amount of stimulation, defined as the point at which a stimulus can be detected 50% of the time.

Difference Thresholds

The extent to which we can detect subtle differences from another comparative stimulus.

Just Noticeable Difference (JND)

The smallest change in stimulation that can be detected; smaller JND indicates greater sensitivity in a sensory modality.

Psychophysics

The study of the relationship between physical stimuli and subjective sensations.

Signal Detection Theory

A theory explaining how and when we detect the presence of a faint stimulus amid background noise based on signal strength and response criteria.

Top-Down Processing

A processing approach driven by knowledge, beliefs, expectations, and goals; more subjective.

Bottom-Up Processing

A processing approach driven by sensory information from the physical world; more objective.

Photoreceptors

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

Rod-Mediated Vision

Vision that occurs in low light through rod photoreceptors, which do not detect color.

Cone-Mediated Vision

Vision that occurs in good lighting through cone photoreceptors, which provide high acuity and color perception.

Trichromatic Coding

The theory that color perception is based on the response of three types of cones: blue, green, and red.

Visual Transduction

The conversion of light into neural signals by visual receptors in the retina.

Geons

Simple geometric shapes that serve as the basic building blocks for object recognition according to the Recognition by Components model.

Face Processing Difficulty in Autism

Autistic individuals tend to perform poorly in recognizing and discriminating faces compared to controls.

Visual Agnosia

A condition resulting from brain damage where a person can see but cannot recognize objects.

Figure-Ground Effect

The tendency to perceive objects as distinct from their background.

Gestalt Laws of Grouping

Principles that describe how we organize visual elements into groups or wholes, including proximity, similarity, closure, and continuity.