| A | B |
|---|
| Sensation | the stimulation of sensory receptors and the transmission of sensory information to the brain |
| Perception | the organization and interpretation of sensory information into meaningful experiences |
| Psychophysics | the study of the relationships between sensory experiences and the physical stimuli that cause them |
| Absolute threshold | the weakest amount of a stimulus that a person can detect half the time |
| Difference threshold | the smallest change in a physical stimulus that can be detected between two stimuli |
| Weber’s law | a psychophysics law stating that for any change in a stimulus to be detected, a constant proportion of that stimulus must be added or subtracted |
| Signal detection theory | the study of peoples tendencies to make correct judgments, misses, and false alarms in detecting the presence of stimuli |
| Pupil | the opening in the iris that regulates the amount of light entering the eye |
| Lens | a flexible, elastic, transparent oval structure in the eye that changes its shape to focus light on the retina; the lens is attached to muscles that adjust the curve of the lens, which in turn adjust the focus |
| Retina | the light sensitive innermost coating of the back of the eye that contains the rods, cones, and neurons that process visual stimuli |
| Optic nerve | the nerve that carries impulses from the retina to the brain |
| Binocular fusion | the process of combining the images received from the two eyes into a single, fused image |
| Retinal disparity | a binocular cue for perceiving depth based on the differences between the images stimulating each eye |
| Auditory nerve | the nerve that carries impulses from the inner ear to the brain, resulting in the perception of sound |
| Vestibular system | three semicircular canals located in the inner ear that provide the sense of balance |
| Olfactory nerve | the nerve that transmits information about odors from the nose to the brain |
| Kinesthesis | the sense that provides information about the position and movement of individual body parts |
| Gestalt | the experience that comes from organizing bits and pieces of information into meaningful wholes |
| Subliminal messages | brief auditory or visual messages that are presented below the absolute threshold so that their chance of perception is less than 50 percent |
| Motion parallax | the apparent movement of stationary objects relative to one another that occurs when the observer changes position |
| Constancy | the tendency to perceive certain objects in the same way regardless of changing angle, distance, or lighting |
| Illusions | perceptions that misrepresent physical stimuli |
| Extrasensory perception | a group of psychic experiences that involves perceiving or sending information outside normal sensory processes or channels; includes four general abilities: telepathy, precognition, clairvoyance, and psychokinesis |
