Visual and memory search by process schizophrenics.

Compared the response times (RTs) of 20 process schizophrenics (10 paranoid and 10 nonparanoid) and 20 nonhospitalized controls (mean ages 39.2, 30.0, and 34.1 yrs, respectively) on a hybrid visual and memory search task in which Ss searched displays of up to 15 letters, reporting whether or not displays contained a target, which in different conditions was drawn from a memorized set of 1, 3, or 6 letters. RTs of all groups increased linearly with the product of the number in the memorized target set and the number of displayed letters. Although the intercepts and RTs of the schizophrenics (there were no paranoid–nonparanoid differences) exceeded those of controls, no group differences were found in slopes or in rates of increase in RT as a function of the number of memorized or displayed items. Results are interpreted in terms of a model proposed by W. Schneider and R. M. Shiffrin (1977), which indicates that process schizophrenics are retarded in processes associated with response production but not in a variety of processing stages involved in the comparison of displayed and memorized information. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)