MIDDLE-EAR MUSCLE-ACTIVITY (MEMA) IN SCHIZOPHRENIA USING A NONINVASIVE TECHNIQUE

Rapid eye movement (REM) sleep middle ear muscle activity (MEMA) was r ecorded in four diagnostic groups: schizophrenics (n = 18), schizoaffe ctives (n = 8), depressives (n = 11) and healthy, nonpsychiatric contr ols (n = 10). Previous work suggested that schizophrenics have higher than normal rates of REM sleep MEMA; this previous study employed the MEMA recording technique of impedance audiometry, which involves a 90- dB stimulus probe tone. The present study, which utilized a silent, pr essure-sensitive transducer (i.e. no acoustic stimulus), was undertake n to determine if the stimulus tone might have elicited excess MEMA in the schizophrenics. In this present study, we observed no significant differences in REM sleep MEMA among the four diagnostic groups, sugge sting that REM sleep MEMA cannot be used as a biological marker to dif ferentiate clinical disorders. This failure to replicate our previous finding of high MEMA rates in schizophrenics is likely due to sampling error; alternatively, high REM sleep MEMA rates might be elicited in a subgroup of schizophrenics with an acoustic stimulus.