Schizophrenia has been associated with a deficit of the prefrontal cortex, which is involved in attention, executive processes, and working memory. The Trail Making Test (TMT) is administered in two parts, TMT-A and TMT-B. It is suggested that the difference in performance between part A and part B reflects executive processes. In this study, we compared the characteristics of hemodynamic changes during TMT tasks between 14 outpatients with schizophrenia and 14 age- and gender-matched healthy control subjects. Using multichannel near-infrared spectroscopy, we measured relative changes in oxygenated hemoglobin concentration, which reflects brain activity of the prefrontal cortex during this task. In both tasks, patients showed significantly smaller activation than controls and, in an assessment of executive functions, a subtraction of oxygenated hemoglobin (oxy-Hb) changes during TMT-A from those of TMT-B showed a decrease in cerebral lateralization and hypoactivity in patients. There was a significant negative correlation between oxy-Hb changes and the severity of psychiatric symptoms. These findings may characterize disease-related features, suggesting the usefulness of oxy-Hb change measurement during TMT tasks for assessing functional outcomes in schizophrenic patients.

Summary:Shiritori is a popular Japanese word chain game that resembles verbal fluency tasks used in Western countries. Recently, shiritori has been used to determine the dominant hemisphere for language and as a rehabilitation tool. However, there are few reports of neuroimaging during shiritori. We used functional magnetic resonance imaging (fMRI) to conduct a detailed study of brain activities during shiritori and observed activation not only of the left inferior frontal gyrus (including the pars opecularis, the pars triangularis and the pars orbitalis), which is a language-related area, but also of the left superior and middle frontal gyri, the right pars orbitalis (inferior frontal gyrus), and the right cerebellar hemisphere. Shiritori is a useful tool for psychological study and rehabilitation. Key words

Aim:  In the present study, we investigated the changes in P3 component in the emotionally charged visual event‐related potentials (ERP) in 30 drug‐naïve schizophrenic patients for up to 1 year. Methods:  Visual oddball event‐related potential was recorded from six recording sites for crying baby or smiling baby photographs. ERP were recorded before the treatment (session 1 [S1]), after 3 months (session 2 [S2]), and after 12 months (session 3 [S3]), as well as in 30 healthy subjects. Results:  Before taking medicine, there were no significant differences in the P300 amplitude between viewing photographs of a crying and a smiling baby. The P300 amplitude was significantly larger at S2 and S3 than at S1 for a crying baby, while there was no significant difference among sessions for a smiling baby after medication. A significant difference of the P300 amplitude was only observed between S3 and healthy subjects for a smiling baby. The P300 latency only when viewing a smiling face became significantly longer at S3 than those at S1 and S2. A significant negative correlation was obtained between the P300 amplitude changes upon viewing crying faces and negative syndrome score changes at the Pz site. Conclusion:  The P300 amplitude induced by crying‐face stimuli may be a state marker and the P300 amplitude caused by smiling‐face stimuli may be a trait marker during recovery in schizophrenic patients. Atypical antipsychotic medications may be useful and may recover cognitive function reflected by the emotionally charged visual P300 components in schizophrenic patients.

Neuroimaging studies have been conducted using word generation tasks and have shown greater hypofrontality in patients with schizophrenia compared with healthy subjects. In this study, we compared the characteristics of oxygenated hemoglobin changes involved in both phonological and categorical verbal fluency between 35 outpatients with schizophrenia and 35 healthy subjects during a Japanese “shiritori” task using single-event-related near-infrared spectroscopy. During this task, the schizophrenic patients showed significantly smaller activation in the prefrontal cortex area than the controls. In addition, a significant positive correlation was obtained between oxygenated hemoglobin changes (prefrontal cortex area, inferior parietal area) and the severity of positive psychiatric symptoms. It is possible that hypofrontality of patients may be a diagnostic assistance tool for schizophrenia, and that the relationship between activation and positive syndrome scores may be of help in predicting functional outcome in patients.

Summary:Various functional imaging studies have demonstrated reduced lateralization of cortical activation during neurocognitive tasks in schizophrenia. -A well-known card game, "concentration", reflects working memory (WM). We compared characteristics of hemodynamic changes in the prefrontal to temporo-parietal areas of the brain during this card game between 24 outpatients with schizophrenia and 24 age-and gendermatched healthy control subjects. Using multi-channel near-infrared spectroscopy, we measured relative changes in oxygenated hemoglobin concentration (oxy-Hb changes), which reflects brain activity during this task. Patients showed reduced lateralization in the midfrontal area, which is involved in executive functions, and in the inferior parietal area, involved in WM subcomponents. We also found a significant negative correlation between left midfrontal region oxy-Hb changes and severity of negative symptoms of schizophrenia. Our results characterized disease-related features, suggesting the usefulness of oxy-Hb change measurement during this card game for assessing functional outcome in schizophrenic patients.