sensation

• the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
• the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory or response.
• the central focal point in the retina, around which the eye's cones cluster
• falling to see visible objects when our attention is directed elsewhere.

perception

• the controversial claim that perception can occur apart from sensory input; includes telepathy clairvoyance, and precognition.
• the central focal point in the retina, around which the eye's cones cluster
• diminished sensitivity as a consequence of constant stimulation.
• the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

bottom-processing

• the sense of body movement and position including the sense of balance
• falling to notice changes in the environment.
• the organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
• analysis that begins with the sensory receptors and works up to the brain's integration of sensory information.

top-down processing

• nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.
• an illusion of movement created when two or more adjacent lights blink on and off in quick succession.
• the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.
• information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

selective attention

• a binocular cue for perceiving depth: By comparing images from the retinal in the two eyes, the brain computes distance - the greater the disparity (difference) between the two images, the closer the objects.
• the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
• the focusing of conscious awareness on a particular stimulus
• a mental predisposition to perceive one thing and not another

inattentional blindness

• the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.
• retinal receptors that detect black, white and gray necessary for peripheral and twilight vision, when cones don't respond.
• hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.
• falling to see visible objects when our attention is directed elsewhere.

change blindness

• depth cues, such as retinal disparity, that depends on the use of two eyes.
• falling to notice changes in the environment.
• the system for sensing the position and movement of individual body parts.
• the focusing of conscious awareness on a particular stimulus

transduction

• in hearing, the theory that relates the pitch we hear with the place where the cochlea's membrane is stimulated.
• conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
• retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. These cells detect fine detail and give rise to color sensations.
• the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

absolute threshold

• the transparent structure behind the pupil that changes shape to help focus images on the retina.
• the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For ex., some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.
• the point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.
• minimum stimulation needed to detect a particular stimulus 50 percent of the time.

signal detection theory

• in hearing, the theory that relates the pitch we hear with the place where the cochlea's membrane is stimulated.
• a theory predicting how and when we detect the presence of a fain stimulus (signal) amid background stimulation (noise). Assumes that there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.
• the activation, often unconsciously, of certain associations, thus predisposing one's perception, memory or response.
• the amount of energy in a light or sound wave, which we perceive as brightness of loudness, as determined yo the wave's amplitude