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Aim: Research efforts aiming at neuroimaging-aided differential diagnosis for psychiatric disorders have been progressing rapidly. A previous multisite study has developed a supplementary diagnostic system using functional near-infrared spectroscopy (fNIRS) that can be easily applied to clinical settings. However, few neuroimaging biomarkers have been developed for the psychosis spectrum with various clinical stages., Methods: We employed the fNIRS as a clinical examination device for 143 participants, comprising 47 ultra-high risk for psychosis (UHR) individuals, 30 patients with first-episode psychosis (FEP), 34 patients with chronic schizophrenia (ChSZ), and 33 healthy controls, who were independent of the previous study. A 12-month follow-up measurement was also carried out on 34 UHR individuals (72%), 21 patients with FEP (70%), and 33 controls. The fNIRS algorithm variables used for classification were the intensity and timing of prefrontal activation following the start of the cognitive task as used in the previous multisite study., Results: The discrimination rate by timing of activation was modest but it became acceptable after adjusting confounding factors. Discrimination by intensity of activation was not improved by similar adjustment. A total of 63.8%, 86.7%, and 81.3% patients were classified as UHR, FEP, and ChSZ, respectively; and 85.1%, 86.7%, and 71.9% of patients in these groups, respectively, were classified as being on the psychosis spectrum. In the follow-up measurement, 88.2% of individuals with UHR and 95.0% of patients with FEP were successfully classified into the psychosis spectrum group., Conclusion: The fNIRS for supplementary clinical examination could be validly applied to differentiating people with the psychosis spectrum in various clinical stages. The fNIRS is a candidate biological marker for aiding diagnosis of psychosis spectrum in routine clinical settings., (© 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.)

Aim: Neurofeedback has been studied with the aim of controlling cerebral activity. Near-infrared spectroscopy is a non-invasive neuroimaging technique used for measuring hemoglobin concentration changes in cortical surface areas with high temporal resolution. Thus, near-infrared spectroscopy may be useful for neurofeedback, which requires real-time feedback of repeated brain activation measurements. However, no study has specifically targeted neurofeedback, using near-infrared spectroscopy, in the frontal pole cortex., Methods: We developed an original near-infrared spectroscopy neurofeedback system targeting the frontal pole cortex. Over a single day of testing, each healthy participant (n = 24) received either correct or incorrect (Sham) feedback from near-infrared spectroscopy signals, based on a crossover design., Results: Under correct feedback conditions, significant activation was observed in the frontal pole cortex (P = 0.000073). Additionally, self-evaluation of control and metacognitive beliefs were associated with near-infrared spectroscopy signals (P = 0.006)., Conclusion: The neurofeedback system developed in this study might be useful for developing control of frontal pole cortex activation., (© 2016 The Authors. Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.)

In alphabet-based language-speaking patients with schizophrenia, category fluency is disproportionately disturbed as compared with phonological fluency. Deficits in category and phonological fluency observed in Japanese patients, however, were similar. The aim of the present study was to replicate these findings by modifying the task to minimize the influence of lack of motivation and concentration in the patients. Similar deficits were found in both types of fluency in Japanese patients. Patients who speak Japanese have deficits in phonological fluency, compared with patients who speak alphabet-based languages, suggesting that the pattern of impairment in verbal fluency in schizophrenia is dependent on the specific language system., (© 2011 The Authors. Psychiatry and Clinical Neurosciences © 2011 Japanese Society of Psychiatry and Neurology.)