Effects of disorganization on choice reaction time and visual orientation in untreated schizophrenics

Several preattentive mechanisms have proved to be sensitive markers of clinical change in schizophrenia. Two related studies of visuospatial orientation used cued target detection combined with choice reaction time, short/long preparation, with or without a signal/target interval (“gap” I “no-gap,” to detect attentional disengagement difficulty in schizophrenia). End points were reaction times, alertness scores, attentional costfbenefit, and validity scores. Study 1, in 13 schizophrenics receiving second-generation antipsychotics and 13 controls, found the same impairment of disengagement as with neuroleptics, but intact reaction times and processing speed, with no hemispheric asymmetry. Study 2, in 12 untreated acute schizophrenia and 12 controls, showed slower reaction times, near-zero alertness in the fixation release condition, and impaired validlinvalid discrimination versus controls, correlating with the Positive And Negative Syndrome Scale disorganization subscore (r=-0.81; P<0.01). Early deficits in the preattentive orientation and visual detection phases are useful for assessing response to psychotropic treatment and establishing clinical correlates in acute schizophrenia.