Chapter 5: Sensation and Perception

Kinesthesis

Provides us with feedback about our muscles and joints positions and movements.

Inattentional Blindness

To refer to the failure of unattended stimuli to register in consciousness.

Critical Periods

During which certain kinds of experiences must occur if perceptual abilities and the brain mechanisms that underlie them are to develop normally.

Perception

Making "sense "of what our senses tell us- is the active process of organizing this stimulus input and giving it meaning.

Amplitude

Refers to the vertical size of the sound waves- that is, the amount of compression and expansion of the molecules in the conducting medium.

Dark Adaption

The progressive improvement in brightness sensitivity that occurs over time under conditions of low illumination.

Transduction

Is the process whereby the characteristics of a stimulus are converted into nerve impulses.

Absolute Threshold

The lowest intensity at which a stimulus can be detected 50 percent of the time.

Retina

A multi- layered light- sensitive tissue at the rear of the fluid- filled eyeball.

Convergence

Is produced by feedback from the muscles that turn your eyes inward to view a close object.

Photopigments

Rods and cones translate light waves into nerve impulses through the action of protein molecules.

Webers law

States that the difference threshold or jnd is directly proportional to the magnitude of the stimulus with which the comparison is being made.

Basilar Membrane

A sheet of tissue that runs its length.

Organ of Corti

Contains about 16, 000 tiny hair cells that are the actual sound receptors.

Rods

Which function best in dim light, are primarily black- and- white brightness receptors.

Taste buds

Chemical receptors concentrated along the tip, edges, and back surface of the tongue.

Lens

An elastic structure that becomes thinner to focus on distant objects and thicker to focus on nearby objects.

Frequency

The number of sound waves, or cycles, per second.

Sensory adaptation

The diminishing sensitivity to an unchanging stimulus.

Decision Criterion

A standard of how certain they must be that a stimulus is present before they will say they detect it.

Pheromones

Chemical signals found in natural body scents.

Fovea

A small area in the center of the retina that contains no rods but many densely packed cones.

Feature Detectors

Fire selectively in response to visual stimuli that have specific characteristics.

Hertz (Hz)

The technical measure of cycles per second; 1 ________ equals 1 cycle per second.

Psychophysics

Studies relations between the physical characteristics of stimuli and sensory capabilities.

Cochlea

A coiled, snail- shaped tube about 3.5 centimeters (1.4 inches) in length that is filled with fluid and contains the Basilar Membrane.

Bottom- up Processing

The system takes in individual elements of the stimulus and then combines them into a unified perception.

Visual Acuity

Ability to see fine detail.

Olfaction

The sense of smell.

Gustation

The sense of taste.

Young Helmholtz trichromatic theory

________: there are three types of color receptors in the retina.

Olfactory Bulb

A forebrain structure immediately above the nasal cavity.

Perceptual Constancies

Allow us to recognize familiar stimuli under varying conditions.

Sensation

Is the stimulus detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain.

Monocular Depth Cues

Which require only one eye.

Illusions

Compelling but incorrect perceptions.

Vestibular sense

The sense of body orientation, or equilibrium.

Figure Ground relations

Tendency to organize stimuli into a central or foreground figure and a background.

Stroboscopic movement

Illusory movement produced when a light is briefly flashed in darkness and then, a few milliseconds later, another light is flashed nearby.

Binocular Disparity

Where each eye sees a slightly different image.

Gate Control Theory

Proposes that the experience of pain results from the opening and closing of gating mechanisms in the nervous systems.

Top Down Processing

Sensory information is interpreted in light of existing knowledge, concepts, ideas, and expectations.

Cones

Are color receptors, function best in bright illumination.

Signal Detection Theory

Is concerned with the factors that influence sensory judgments.

Nerve Deafness

Caused by damaged receptors within the inner ear or damage to the auditory nerve itself.

Perceptual Schema

A mental representation or image containing the critical and distinctive features of a person, object, event, or other perceptual phenomena.