SAXITOXIN (STX)
Naturally produced neurotoxin in certain species of marine dinoflagellates. One of the most potent natural toxins known, acts on the…
SCANNING SPEECH
Speech which proceeds slowly and is marked by variations of intonation and unintentional delays between syllables. Representative of ataxic dysarthria.
SCHAFFER COLLATERAL
Axon collaterals given off by CA3 pyramidal cells in the hippocampus which project into CA1 and are an integral part…
SCHIZOIDISM
Array of behavioral patterns which incorporates reclusiveness, quietness, and a general introversion, pointing to a division between an individual and…
SCHIZOTYPAL PERSONALITY DISORDER
In DSM-IV-TR, extreme character dysfunction identified by assorted oddities of cognition, perceptual experience, speech patterns, and behavior patterns which are…
SCHRODER STAIRCASE
Ambivalent illustration featuring a staircase which appears to be seen from different perspectives as the observer changes focus. Also known…
SCREENING AUDIOMETRY
Rapid measurement of the hearing of an individual or a group against a predetermined limit of normality.
SEASONAL VARIATION
Often attributed to photoperiodism, changes which occur in behavioral, psychological, and physiological patterns as seasons vary or in reaction to…
SECONDARY CONTROL
Behavior pattern which does not directly control the environment, but is intended to alter oneself to be more compatible with…
SECOND-ORDER CONDITIONING
Use of a previously successfully conditioned stimulus as the unconditioned stimulus for further conditioning, employed in Pavlovian conditioning. See: higher…
SEGREGATION ANALYSIS
Enumeration of progeny according to distinct and mutually exclusive phenotypes; used as a test of a putative pattern of inheritance…
SELECTIVE CELL DEATH
Process in initial development wherein neurons which are not stimulated by sensory or motor experience wither and die.
SELECTIVE VALUE
Comparative significance of any aspect in assessing the evolution of internal organs, characteristics, or species by means of natural selection.…
SADISTIC PERSONALITY DISORDER
Personality disorder which is marked by a pervasive pattern of cruel, demeaning, and aggressive behavior. Satisfaction is gained in intimidating,…
SALICYLATES
Class of medications based on salicin (obtained from the bark of the willow tree) or its compounds; employed as analgesics,…