ABSTRACT

Disorders of the inhibitory control of attention have long been noted in schizophrenia spectrum patients. Operational, behavioral techniques were first applied to the construct of impaired sensory filtering in schizophrenia in the 1970s. Braff et al. (1978) noted Frances Graham's (1975) observation of short lead interval inhibition in normal subjects, and hypothesized, then demonstrated, that schizophrenia patients have diminished short lead interval inhibition reflecting impaired gating. Although originally thought to reflect an automatic, preattentive sensorimotor gating function, Dawson et al. (1993) demonstrated that short lead interval inhibition is modulated by attention and may represent a state-independent vulnerability marker for schizophrenia. The findings of impaired short lead interval inhibition in schizotypal subjects (Cadenhead et al., 1993), in conjunction with confirmation of a theoretical link between impaired short lead interval inhibition and thought disorder in schizophrenia patients (Perry & Braff, 1994), added further support to the notion that impaired short lead interval inhibition reflects a trait-linked deficit in sensorimotor gating in schizophrenia spectrum individuals. The neural basis of sensorimotor gating deficits in rats is now better understood, allowing the study of proposed brain abnormalities in schizophrenia patients in animal models. Future directions in application of short lead interval inhibition techniques to schizophrenia spectrum research will continue to include parallel animal model research in conjunction with studies of medication effects, gross and specific psychopathology, gender, laterality, family studies, and attentional manipulation in schizophrenia spectrum populations.