[Characteristics of single event-related cerebral hemodynamics during verbal task in emotionally charged state measured by multi-channel near-infrared spectroscopy (NIRS) in patients with schizophrenia: comparison with healthy subjects].

Neared infrared spectroscopy (NIRS) is one of the recently developed methodologies which can measure cerebral blood volumes to determine the blood hemoglobin (Hb) concentration simultaneously at multiple points with marked time resolution. Monitoring the changes in the Hb concentration yields site-specific readings on blood flow and, thus, on neural activities. The aim of this study was to examine the characteristics of a single event-related oxyhemoglobin concentration [oxy-Hb] changes in patients with schizophrenia using multi-channel NIRS during a word generation task, Japanese 'Shiritori', and single-word generation task in an emotionally charged state induced by three facial expressions of "crying", "neutral", and "smiling" babies' photographs. Thirty-four patients with schizophrenia and 34 age-matched healthy controls participated in the present study after giving consent. In healthy controls, [oxy-Hb] changes when viewing the "crying" baby's photograph were significantly larger than when viewing the "smiling" baby's photograph. On the other hand, in patients with schizophrenia, [oxy-Hb] changes when viewing the "smiling" baby's photograph were significantly larger than when viewing the "crying" baby's photograph. These results suggest that cautions/execution functions in patients with schizophrenia during the single event word "Shiritori" task measured by multi-channel NIRS were impaired. It was also suggested that, in patients with schizophrenia, the affective reaction influenced by each photograph may be different from healthy controls (mismatch). Multi-channel NIRS can be a useful tool for research and clinical purposes in psychiatry.