. Author manuscript; available in PMC: 2010 May 26.

Published in final edited form as: Am J Psychiatry. 2008 Oct 15;165(12):1585–1593. doi: 10.1176/appi.ajp.2008.08030395

TABLE 4.

Behavioral and Cognitive Performance Tasks for Schizophrenia Patients Randomly Assigned to MK-0777 or Placebo

Performance Task	Placebo Group				MK-0777 Group				Between- Group Effect Size^a
	Baseline		Week 4		Baseline		Week 4
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
AX Continuous Performance Test task ^b
d′	0.7	0.9	0.7	0.9	0.9	0.7	1.9	0.9	1.07
N-back task ^c
Reaction time	669	158	684	101	874	238	786	231	0.84
Error rate	0.250	0.028	0.297	0.075	0.247	0.102	0.239	0.062	0.83
Preparing to Overcome Prepotency task ^d
Reaction time	36	61	66	55	66	48	57	66	1.74
Error rate	0.064	0.068	0.031	0.074	0.034	0.050	0.042	0.042	−0.35

Positive effect sizes indicate that the MK-0777-treated group showed the hypothesized performance improvements (relative to the placebo group). Only the Preparing to Overcome Prepotency task error rates showed effects in the opposite direction.

Data for the d′ long-delay condition are reported.

Data for the 2-back condition are reported.

Data for performance differences between high and low control conditions are reported.