 | Term | Definition |
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sensation |
the process by which our sensory receptors and nervous system recieve and represent stimulus energies from our environment |
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perception |
the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events |
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bottom-up processing |
analysis that begins with the sense receptores and works up to the brain's integration of sensory info |
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top-down procesing |
information processing guided by higher level mental processes as when we construct perceptions drawing on our expereience and expectations |
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psychophysics |
the study of relationships between the physical characteristics of stimuli, such as their intensity and our psychological experience of them |
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absolute threshold |
the min. stimulation needed to detect a particular stimulus 50% of the time |
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signal detection theory |
a theory predicting how and when we detect the presence of a faint stimulus "signal" amid background stimulation "noise" |
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subliminal |
below one's absolute threshold for conscious awareness |
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difference threshold |
the min. difference between two stimuli required for dection 50 % of the time |
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Weber's law |
the principle that to be perceived as different, 2 stimuli must differ by a constant min percentage |
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sensory adaptation |
diminished sensitivity as a consequence of constant stimulation |
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transduction |
conversion of one form of energy into another |
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wavelength |
distance from peak of one light or sound wave to peak of next |
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hue |
dimension of color that is determined by the wavelength of light |
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intensity |
amount of energy in a light or sound wave, which we can percieve as brightness or loudness, as determined by the wave's amplitude |
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pupil |
adjustable opening in the center of the eye through which light enters |
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iris |
a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening |
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lens |
transparent structure behing the pupil that changes shape to help focus images on the retina |
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accommodation |
the process by which the eye's lens changes shape to focus on near or far objects on the retina |
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retina |
the light sensitive inner surface of the eye containing the receptre rods and cones plus layers of neurons that begin the processing of visual information |
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acuity |
the sharpness of vision |
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nearsightedness |
condition in which nearby objects are seen more clearly than distant obejects because distant objects focus in front of the retina |
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farsightedness |
a condition in which faraway objects are seen more clearly than near objects because the image of near objects if focused behind the retina |
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rods |
retinal receptors that detect black, white, and gray; |
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cones |
receptor cells that concentrated near center of retina funciton in well lit conditions; detect fine detail and color |
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optic nerve |
nerve carries neural impulses from the eye to the brain |
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blind spot |
point at which the optic nerve leaves the eye creating a blind spot |
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fovea |
the central focal point in the retina around which the eye's cones cluster |
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feature detectors |
inner cells in the brain that respond to specific features of the stimulus such as shape angle or movement |
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parallel processing |
the processing of several aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. |
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Yough-Helmholts trichromatic |
the theory that the retina contains three differenlt color receptors, red, green and blue, which can combine to form different colors |
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opponent process theory |
the theory that opposing retinal processes enable color vision |
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color constancy |
perceiving familar objects as having consistent color even if changing illumination alters the wavelengths reflected by the object |
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audition |
the sense of hearing |
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frequency |
the numer of complete wavelengths that pass a point in a given time |
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pitch |
a tone's highness or lowness; depends on frequency |
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middle ear |
the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup_ that concentrate the vibrations of the eardrum on the cochlea's oval window |
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inner ear |
the innermostpart of the ear, containing the cochlea, semicircular canals, and vestibular sacs |
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cochlea |
a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses |
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place theory |
in hearing the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated |
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frequency theory |
in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequecy of a tone, thus enabling us to sense its pitch |
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conduction hearing loss |
hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea |
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sensorineural hearing loss |
hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves aka nerve deafness |
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gate-control theory |
the thoery that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass 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 |
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sensory interaction |
the principle that one sense may influence another, as when teh smell of food influences its taste |
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kinestheseis |
the system for sensing the position and movement of individual body parts |
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vestibular sense |
the sense of body movement and position, including the sense of balance |
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consciousness |
our awareness of ourselves and our environment |
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biological rhythms |
periodic physiological fluctuations |
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circadian rhythm |
the biological clock; regular bodily rhthms that occur on a 24 hour cycle |
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REM sleep |
rapid eye movement, a recurring sleep stage during vivid dreams commonly occur; paradoxical sleep because the muscles are relaxed but other body systems are actives |
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alpha waves |
the relatively slow brain waves of a relaxed awake state |
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sleep |
periodic natural reversible loss of consciousness as distinct from unconsciousness resulting from a coma, general anesthesia or hibernation. |
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hallucinations |
false sensory experiences such as seeing somethign in the absence of an external visual stimulus. |
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delta waves |
the large, slow brain waves associated with deep sleep |
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insomnia |
recurring problems in falling or staying asleep. |
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narcolepsy |
a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times |
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sleep apnea |
a sleep disorder characterized by temporary cessations of breathing during sleep and consequent momentary reawakenings. |
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night terrors |
a sleep disorder characterized by by high arousal and an apperance of being terrified; unlike nightmares, night terrors occur during stage 4 sleep, within 2 or 3 hours of falling asleep and are seldom remembered. |
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dream |
a sequence of images, emotions, and thoughts passing through a sleeping person's mind. Dreams are notable for their hallucinatory imagery, discontinuities and incongruities and for the dreamer's delusional acceptance of the content and later difficulties remembering it. |
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manifest content |
according to freud, the remembered story line of a dream (as distinct from its latent content). |
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latent content |
according to Freud the underlying meaning of a dream |
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hypnosis |
a social interaction in which one person sugests that certain perceptions will spontaneously occur |
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REM rebound |
tendency for REM sleep to increase following REM sleep deprivation |
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posthypnotic amnesia |
supposed inability to recall what one experienced during hypnosis; induced by hypnotist;s suggestion |
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posthypnotic suggestion |
a suggestion made during a hypnosis session to be carried out after the subject is no longer hypnotized; used to help contorl undesired behaviors |
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dissociation |
a split in consciousness which allows some thoughts and behaviors to occur simultaneoulsy with others |
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hidden observer |
Hilgard's term describing a hypnotized subject's awareness of experiences such as pain that go unreported during hypnosis |
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psychoactive drug |
a chemical substance that alters perceptions and mood. |
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tolerance |
the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug's effect. |
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withdrawal |
the discomfort and distress that follow discontinuing the use of an addictive drug |
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physical dependence |
a physiological need for a drug marked by unpleasant withdrawal symptoms when the drug is discontinued |
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psychological dependence |
a psychological need to use a drug, such as to relieve negative emotions |
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depressants |
drughs that reduce neural activity and slow body functions |
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stimulants |
drugs that excite neural activity and speed up body functions |
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hallucinogens |
distort perceptions and evoke sensory images in absense of sensory input. |
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barbiturates |
drugs that depress the activity of the Central nervous system, reducing anxiety but impairing memory and judgement |
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opiates |
opium and its derivavatives such as morophine and heroin; they depress neural activity temproarily lessening pain and anxiety |
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amphetamines |
drugs that stimulate neural activity causing speeded-up body functions and associated energy and mood changes |
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ecstasy (MDMA) |
a synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy but with short-term heath risks and longer term harm to serotonin-producing neurons and to mood and cognition |
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LSD |
a powerful hallucinogenic drug; lysergic acid diethylamide |
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THC |
the major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations |
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near-death experience |
an altered state of consciousness reported after a close brush with death (often similar to drug-induced hallucinations) |
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Dualism |
the presumption that mind and body are two distinct entities that interact |
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monism |
the presumption that mind and body are different aspects of the same thing |
