Published papers

In the present study, we used the typical false recognition paradigm to test a hypothesis that the ventromedial prefrontal cortex (VMPFC) mediates context judgment and retrieving past events. Eight VMPFC patients and ten normal control subjects were first requested to learn 18 sets of 14 semantic associates. In the test phase, the participants were asked to recognize for pairedwords including true words, related lures, and unrelated lures. The VMPFC patients showed significantly higher false alarm rate than the normal subjects for lure words. A further analysis suggests that the VMPFC patients were more likely to fail to judge contexts and to retrieve past events.

We report a case with prosopagnosia for familiar faces due to a fresh cerebral infarction in the lateral region of the right occipital lobe in addition to an extensive old infarction of the left occipital lobe. The patient was a right-handed man in his 70s. Prosopagnosia and difficulties in recognizing facial expressions were observed, and attention function and processing speed were reduced in the present case. General cognitive function and visuospatial function remained normal except for facial cognition. Prosopagnosia was caused by the brain network dysfunction between the occipital face area, the fusiform face area and the anterior temporal lobe of the left and right hemispheres. Facial cognition, including age and gender judgments, was preserved. Diffusion tensor tractography suggested that this was due to the preservation of white matter fibres in the inferior fronto-occipital fasciculus and inferior longitudinal fasciculus of the right hemisphere. It is thought that cognitive rehabilitation to increase attention and processing speed is important for improving recognition of facial expressions.

The conventional analysis assumes a constant mental state during scanning and assesses the strength of functional connectivity as the average of the entire fMRI data. However, it is suggested that even at rest, functional connectivity may change with time, and the conventional analysis has not been able to fully evaluate its properties. To overcome this limitation, many studies propose an index called dynamic functional connectivity (dFC) or time-varying functional connectivity (TVFC) or the chronnectome. This article reviews the significance and methods of dFC, examples of its application in clinical studies, and its limitations. Finally, we discuss its potential for clinical application.

type:text This paper reviews memory functions in the frontal pole and the medial parietal areas. Many studies have focused on both areas through various approaches, including neuropsychology, neuroimaging, psychiatry, neurology, and neurosurgery. In addition to the memory-related functions, both areas have substantially quite complex higher-order cognitive functions, including executive functions, multi-task processing, future-oriented cognition, self-related cognition, and spatial cognition. Here, I picked up some fundamental perspectives in each area by reviewing previous studies to elucidate how the areas relate memory processing and provide some facets for delineating the whole aspect of memory mechanisms. 特集 : 伊東裕司教授 退職記念号 寄稿論文

This article first reviews some methods for measuring psychological pain, as a subjective sensation, and outlines its neural mechanisms. Particularly, the involvement of the neural basis of the salience network, which consists of the insula and cingulate cortex, is described focusing on its relation to interoception. Next, we focus on the disease concept of psychological pain as a pathological condition, review some studies on somatic symptom disorder and related disorders, and discuss some possible methods of pain and future research directions.

嫌悪，恐怖，喜びといった情動の生起には，自律神経反応が伴っている。情動によって生じる自律神経反応は意識的に感じられることがあり，自律神経反応を含めた身体内部の状態の知覚は内受容感覚と呼ばれている。本研究では，内受容感覚の意識的な感じやすさが，情動の種類あるいは性格傾向の違いによって異なるのかを検討した。参加者は嫌悪，恐怖，喜びを喚起させる画像を見たときに，自身の身体に変化が生じたかを答えた。内受容感覚を知覚できた刺激の数は嫌悪の情動が最も多く，次いで恐怖，喜びの順番であった。また，アレキシサイミア傾向が高い人は，恐怖の情動に対して身体の変化を感じにくく，状態不安の高い人は，喜びの情動に対し，身体の変化を意識的に知覚しやすかった。これらの結果は，意識的な内受容感覚は情動の種類によって感じやすさが異なっていること，それは性格傾向の影響も受けていることを示唆している。

Individuals with high anxiety have a specific tendency to update beliefs based on the given information in ambiguous situations. However, it is unclear what aspect of information evaluation is specific in individuals with high anxiety. We explored the factor of these changes by applying the Bayesian update to the bead task. In the task, we presented two bins containing beads of two different colors in different proportions. Each time a bead was presented, they reported a subjective belief about the bin from which the beads were extracted. In the analysis, we assumed that the current confidence was obtained by adding the information of the current bead to the confidence at the previous time point. We then estimated whether individuals were more evaluated on the previous confidence or the current information. The results showed that individuals with high anxiety underestimated the information obtained from the current bead.