"Normal" personality correlates of sensorimotor, cognitive, and visuospatial gating.

Specific psychiatric disorders are characterized by impaired selective inhibition or "gating" of responses to sensory or cognitive information. Less is known about gating differences among normal individuals. We tested carefully screened controls in measures of central inhibition: prepulse inhibition (PPI) of startle, the Stroop test, and negative priming (NP). Subjects were defined as "normal" or "psychosis prone," based on theoretically and empirically derived MMPI criteria. Performance on all measures by "psychosis-prone" individuals suggested reduced sensorimotor gating and/or increased cognitive or visual interference. Performance was most impaired in individuals scoring highest on the MMPI Goldberg Index, which was originally designed to distinguish "psychotic" from "neurotic" inpatients. Inhibition in Stroop and NP was correlated across all subjects, but PPI was not correlated with other measures. Gender differences were noted in PPI (male > female), but not Stroop or NP. Performance deteriorated with age in Stroop and NP, but not PPI. The results are discussed as they relate to psychophysical and neural correlates of normal personality dimensions.