Modification of performance on the span of apprehension, a putative marker of vulnerability to schizophrenia

The present study examined the effectiveness of 2 types of intervention (contingent monetary reinforcement and enhanced instruction) on span of apprehension performance. Forty chronic schizophrenia inpatients (26 men, 14 women) received a 3- and 12-letter array version of the span of apprehension task 4 times: baseline, intervention, immediate posttest, and 1-week follow-up. All patients were randomly assigned to 1 of 4 groups that differed according to method of intervention: repeat administration, monetary reinforcement only, instruction only, and monetary reinforcement plus instruction. The combination of monetary reinforcement plus instruction yielded significantly greater improvement in span accuracy than the other methods of intervention. These findings suggest that performance on this putative vulnerability indicator can be modified through certain interventions.