Sensation/Perception

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Bottom-up processing

Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.

Top-down processing

Information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Selective attention

Focusing of conscious awareness on a particular stimulus.

Inattentional blindness

Failing to see visible objects when our attention is directed elsewhere.

Change blindness

Failing to notice changes in the environment; a type of inattentional blindness.

Transduction

The conversion of one form of energy to another, transforming stimulus energies into neural impulses.

Psychophysics

The study of relationships between physical characteristics of stimuli and our psychological experience of them.

Absolute threshold

The minimum stimulation needed to detect a particular stimulus 50% of the time.

Signal detection theory

Predicts how and when we detect the presence of a faint stimulus amid background stimulation.

Difference threshold

The minimum difference between two stimuli required for detection 50% of the time.

Weber’s Law

To be perceived as different, two stimuli must differ by a constant minimum percentage.

Sensory adaptation theory

Diminished sensitivity as a consequence of constant stimulation.

Perceptual set

Mental tendencies and assumptions that affect what we hear, taste, feel, and see.

Context

The power of content significantly influences perception, as different perspectives can alter our views.

Motivation

Motives that give us energy and drive which can influence our performance and biases in perception.

Emotion

An emotional state can impact how we perceive sounds and experiences around us.

Wavelength

The distance between one wave peak to the next, affecting the color we perceive.

Intensity

The amount of energy in a light wave, determining the brightness of colors.

Rods

Photoreceptors that detect black, white, and gray; necessary for peripheral and twilight vision.

Cones

Photoreceptors that detect fine detail and provide color sensations.

Optic nerve

A bundle of neurons that carries neural impulses from the eye to the brain.

Young-Helmholtz Trichromatic Theory

The idea that any color can be created by combining light waves of three primary colors: red, green, and blue.

Opponent-Process Theory

Opposing retinal processes enable color vision and prevent seeing mixes of certain colors.

Feature detection

The visual processing that decomposes an image and reconstructs it in our brain.

Binocular cues

Depth cues that depend on the use of two eyes to perceive distance.

Monocular cues

Depth cues that can be perceived with one eye, aiding in distance judgment.

Audition

The act of hearing and processing sound.

Amplitude (in sound)

The height of sound waves, determining perceived loudness.

Frequency (in sound)

The length of sound waves that determines pitch.

Cochlea

A coiled, bony fluid-filled tube in the inner ear, where sound waves trigger neural impulses.

Gustation

The sense of taste, which involves chemical processes.

Olfaction

The sense of smell, which detects scent-laden molecules through olfactory receptors.

Gate-Control Theory

A theory that suggests the spinal cord contains a neurological gate that either blocks or allows pain signals to pass to the brain.

Phantom limb syndrome

The sensation of pain or movement in a non-existent limb.