Recent studies of selective attention in schizophrenia patients suggest a particular pattern of single-trial Stroop performance: increased facilitation but not interference in reaction times (RTs), combined with increased error interference. Our Stroop task analysis suggests that this pattern can be explained by a selective attention deficit if one accounts for (1) performance in the congruent condition; (2) the nature of the neutral stimulus; (3) the relationship between accuracy and RT; and (4) response set effects. To test these hypotheses, we examined Stroop performance in 40 DSM-IV schizophrenia patients and 20 healthy control subjects, using a range of neutral stimuli (color patches, noncolor words, color words not in the response set). The findings confirmed several of our predictions and the results were consistent with the hypothesis that abnormal Stroop performance in schizophrenia reflects a failure to adequately attend to the task-appropriate stimulus dimension (color). This inattention affects both the congruent and incongruent conditions and multiple points in the information processing pathway.
IMPORTANCEThe extent of cognitive deterioration after schizophrenia (SZ) onset is poorly understood because prior longitudinal studies used small samples of older individuals with established illness. OBJECTIVE To examine the association of age at onset and subsequent longitudinal course of prefrontal activity during the first 2 years of illness in youths with SZ and healthy control participants (HCs). DESIGN, SETTING, AND PARTICIPANTSThis naturalistic, longitudinal, functional magnetic resonance imaging (fMRI) study included patients with recent-onset SZ and HCs aged 12 to 25 years enrolled in an ongoing study of cognition in recent-onset psychosis in the Sacramento, California, area from October 13, 2004, through June 25, 2013. Participants completed clinical assessments and an established measure of cognitive control, the AX Continuous Performance Task (AX-CPT), during fMRI at baseline and at 6-, 12-, and 24-month follow-up. Whole-brain, voxelwise, and an a priori dorsolateral prefrontal cortex (DLPFC) region of interest analyses were performed. Group differences in developmental trajectories were examined by focusing on behavioral performance (d′-context) and cognitive control-associated brain activity. The association of antipsychotic medication and clinical factors were also examined. Data were analyzed from April 15, 2015, through August 29, 2017. MAIN OUTCOMES AND MEASURES Primary outcomes included group differences (HC vs SZ) in behavioral performance (d'-context from AX-CPT) and brain activity for cue B-A trials of the AX-CPT in an a priori DLPFC region of interest at baseline and across the age span. Secondary analysis examined the influence of antipsychotics on behavioral performance and DLPFC activity. RESULTSAmong the sample of 180 participants (66.1% male; mean [SD] age at baseline, 19.2 [3.2] years), 87 patients with SZ (mean [SD] age, 19.6 [3.0] years) showed impaired performance compared with 93 HCs (mean [SD] age, 18.8 [3.4] years) across the age span (estimated difference [SE], −0.571 [0.12], d′-context; P < .001). Patients with SZ showed reduced activation in the DLPFC and parietal cortex (false discovery rate cluster corrected to P < .05) compared with HCs under conditions of high cognitive control at baseline. Region-of-interest analysis showed reduced activation in the DLPFC bilaterally for patients with SZ, with a trajectory that paralleled that of HCs across the age span (left DLPFC β [SE] estimates, 0.409 [0.165] for the HC group and −0.285 [0.130] for the SZ group [main effect of group, P = .03]; right DLPFC β [SE] estimates, 0.350 [0.103] for the HC group and −0.469 [0.157] for the SZ group [P = .003]). Antipsychotic medication, clinical symptoms, and global functioning were associated with SZ performance.CONCLUSIONS AND RELEVANCE During the initial 1 to 2 years after illness onset, young individuals with SZ showed deficits in DLPFC activation and cognitive control, with developmental trajectories comparable to those of HCs. Younger age at onset was not associated with reduced cogniti...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.