Impact of time estimation on the crossover effect in schizophrenia.

To test the role of time estimation in the crossover effect (COE), reaction times (RTs) of schizophrenic, alcoholic, and normal subjects were collected in two conditions: a standard visual RT task with different preparatory intervals in regular or irregular series, and a time information condition with the intervals filled by a visual countdown analogue. In the standard condition, the COE was found not only for schizophrenics but also for alcoholics. Time information reduced RTs in all groups, but not the average COE in schizophrenics. The relationship between RTs and simultaneously collected event-related potentials was examined.