Distinct neural activation patterns in executive functions of schizophrenia patients with predominant positive and negative symptoms: an fNIRS study.

Objective: To investigate the differences in executive functions, specifically cognitive flexibility and inhibitory control, between schizophrenia (SCH) patients with predominantly positive symptoms (PSD) and those with predominantly negative symptoms (NSD), compared to healthy controls, using functional near-infrared spectroscopy (fNIRS).

Methods: Fifty-two patients with SCH and 29 control subjects were recruited in the study. We employed fNIRS to measure brain activation while participants performed 2 tasks: a cognitive flexibility-switching task and the Stroop task, which assesses inhibitory control. Performance metrics included accuracy and reaction time. The study included 3 groups: SCH patients with PSD, SCH patients with NSD, and healthy controls.

Results: Patients with SCH exhibited lower accuracy and longer reaction times compared to healthy controls. In terms of brain activation, the PSD group showed the highest levels of prefrontal activation, followed by healthy controls, while the NSD group had the lowest activation levels. Patients had lower accuracy and longer reaction times than healthy controls. The PSD group showed excessive activation in both prefrontal cortex and the dorsolateral prefrontal cortex during both the congruent condition and incongruent condition of the Stroop task. In contrast, the NSD group exhibited higher prefrontal activation under congruent conditions but significantly reduced activation under incongruent conditions.

Conclusion: Our findings highlight distinct patterns of executive function deficits and brain activation in SCH patients with PSD and NSD. These results suggest that symptom profiles may influence the nature and severity of cognitive impairments and associated neural mechanisms. Future research should further explore these differences to inform targeted interventions and improve clinical outcomes for individuals with SCH.