Background: Sensorimotor gating abnormalities have been previously correlated with thought disturbance in schizophrenic patients. These correlative studies have led to the hypothesis that sensorimotor gating abnormalities may underlie thought disturbance. Several authors have cautioned, however, that this and similar hypotheses are supported by data recorded at different times or during resting states" and therefore incorrectly assume that the observed association represents a concurrent relationship. To address this issue, sensorimotor gating and thought disturbance were measured in close temporal proximity, thus strengthening the evidence for the association of these 2 abnormalities in schizophrenic patients.
Methods: Twenty-one schizophrenic men were assessed on measures of sensorimotor gating and thought disturbance. Sensorimotor gating was examined operationally via the use of prepulse inhibition. Thought disturbance was assessed via the Rorschach test measures of perceptual inaccuracy, disordered cognition, and the expression of normally repressed contents. Symptom rating scales (the Scale for the Assessment of Positive Symptoms and the alogia subscale of the Scale for the Assessment of Negative Symptoms) were also used.
Results: Deficient prepulse inhibition correlated significantly with 2 of the 3 Rorschach-derived thought disturbance measures. Prepulse inhibition was not correlated significantly with symptom rating scales. The Rorschach measure of impaired perceptual accuracy independently accounted for 60% of the variance in prepulse inhibition measures and contributed 35% of the unique variance beyond the effect attributable to the Scale for the Assessment of Positive Symptoms.
Conclusions: Assessment of information processing and thought disturbance measures in close temporal proximity resulted in strong evidence that gating deficits correlate highly with measures of perceptual and reasoning disturbances. This relationship may form an important basis for the cognitive dysfunction observed among schizophrenic patients.