Prefrontal Activity Measured by Functional Near Infrared Spectroscopy During Divergent and Convergent Thinking in Bipolar Disorder.

INTRODUCTION: Biographical research as well as some controlled studies point out to a relationship between bipolar disorder (BD) and creativity. Neurobiological underpinnings of this relationship are unclear. Although there is no consensus on the definition of creativity, Alternative uses Test (AuT) and Remote Association Test (RAT) are frequently used to measure convergent and divergent creativity. We aimed to examine prefrontal cortex (PFC) activity with functional near-infrared spectroscopy (fNIRS) during the RAT and AuT tests in subjects with BD. METHODS: We measured PFC activity in subjects with remitted BD (N=31) and healthy control subjects (N=27) with fNIRS during divergent and convergent thinking tasks (AuT and RAT respectively). We were particularly interested in the antero-posterior dissociation of the activity within the PFC according to the two task domains. RESULTS: We found that the index subjects displayed lower performance than healthy controls during the AuT and the RAT. AuT and RAT were associated with different activities in the two groups. Anterior PFC (aPFC) activity was higher than posterior PFC (pPFC) activity during the RAT in the index group, and during the AuT in the control group. aPFC activity was negatively correlated with the RAT performance in the index group. CONCLUSION: Higher activity in the aPFC may be the functional neuro-anatomical correlate of low convergent creativity performance in BD.

[Prefrontal Cortex Activity During Facial Affect Processing in Schizophrenia: Association with Clinical Symptoms and Social Cognitive Functions]. / Sizofrenide Yüzdeki Duygu Ifadelerini Tanima Sirasindaki Prefrontal Korteks Aktivitesinin Klinik Belirtiler ve Sosyal Bilis Islevleriyle Iliskisi.

OBJECTIVES: In the present study, we aimed to investigate the prefrontal cortex (PFC) activity during facial affect recognition in schizophrenia, as well as the association of this activity with symptom severity and with the higher order social cognitive functions, namely recognition of false beliefs, faux-pas and hinting. METHOD: Functional near infrared spectroscopy (fNIRS) was used to measure frontal cortical activity during a neuroimaging task prepared with a standard set of pictures of facial affect. The data of the Index Group (IG) consisting of 27 subjects with DSM-IV based diagnoses of schizophrenia and schizophreniform disorder and control group (CG) (N=25) were compared. The control condition was to detect nonaffective changes on a neutral face. Associations with frontal activity during affect recognition and clinical symptoms, false belief recognition, hinting and faux-pas were investigated. RESULTS: Prefrontal activity during both affective and non-affective conditions was higher in the IG than the CG. The IG performed worse than the CG in social cognitive tests. Social cognitive test performance was not correlated with cortical activity. There were no correlations between education status, age and PFC activity in both groups. In the IG, right ventral prefrontal cortex (VPFC) and right medial prefrontal cortex (mPFC) activities were associated with hallucination severity. CONCLUSION: These results suggest the presence of hyperfrontality during face processing in schizophrenia. Results also suggest that schizophrenia patients require more frontal resources to achieve a performance comparable to that of healthy controls in order to detect both affective and non-affective changes on a face. There might be a relationship between facial processing and hallucinations.