Assessment of differential attention mechanisms in seizure disorders and schizophrenia.

This study examines differential attention deficits in 19 temporal lobe epilepsy (TLE) patients, 15 generalized seizure patients (GSP), and 19 schizophrenic patients, compared to 20 normal controls. All participants were tested on a variable foreperiod reaction time (RT) task and continuous performance test (CPT). Temporal lobe epilepsy patients and schizophrenic patients show crossover deficits on the RT task requiring a conscious, effortful, preparatory motor set; while GSP show impairments on the CPT requiring vigilant, self-directed attention to external stimuli. The results suggest separate cortical and subcortical brain systems in the respective attentional deficits and in the etiologies of TLE, GSP, and schizophrenic disorders.