Prepulse-elicited motor reactions do not differ between schizophrenia patients and control subjects

Electromyographic (EMG) measures were made of the eyeblink response to stimuli 2-16 dB over a 70-dBA noise background as well as the eyeblink response to startling 115-dBA pulses in 15 schizophrenia patients and 10 control subjects. In patients and in control subjects, weak stimuli did not elicit EMG activation. Startling stimuli elicited robust EMG activation in both groups. Compared with control subjects, schizophrenia patients are not more sensitive to motor-activating effects of weak acoustic stimuli that served as prepulses in published reports of prepulse inhibition deficits in schizophrenia. Thus, differential sensitivity to the motor-activating effects of prepulses should not contribute to reduced prepulse inhibition in schizophrenia patients versus control subjects.