論文

本稿では，まず主観的な感覚である心理的な痛みの定義およびその原因となる要因について述べ，痛みの症状を生み出す認知神経メカニズムについて概説する．特に，島皮質および帯状皮質前部から構成されるセイリエンスネットワークを中心とした神経基盤の関与について，内受容感覚との関連性に着目しながら述べる．さらに，慢性的な痛みを解釈する認知神経科学の理論的枠組みを紹介し，内受容感覚のベースとなる自律神経活動の特殊性に焦点を当て，身体症状症をはじめとする臨床病態について考察する．

現在遂行中の行為とは無関係な事柄へと思考がさまよう現象をマインドワンダリング (mind wandering, 以下, MW)という。本研究では，契機が不明で無意図的なMWの生起に対して，内受容感覚が与える影響について検討した。参加者は，心拍検出課題（Schandry, 1981）とVigilance Taskの2つの課題をおこなった。心拍検出課題の成績によって，参加者を内受容感覚高群・低群に分けた。Vigilance Taskの後半ブロックにおいて，参加者の前腕部に振動刺激を閾下呈示することで，心拍変化を誘導した。その結果，内受容感覚高群は，低群と比較すると，振動が呈示されたブロックにおいて，発生したMWがその後の試行においても継続する確率が高かった。この結果は，内受容感覚が正確な人においては，振動の閾下呈示による断続的な内受容情報の変化が， MWの発生・継続を誘発する可能性を示唆している。

我々は日常的に様々なイベントを経験するが，その経験前から、経験後にかけて、イベントに対する主観的な時間的距離を知覚している。経験前の時点からイベントまでに感じる時間的距離は、経験後の時点からイベントまでに感じる時間的距離よりも過小評価されるという非対称性があり、これを時間的ドップラー効果という。本研究では、実際にストレスイベントを経験させ、イベント前後におけるイベントまでの時間的距離の主観的な感覚をイベント前後20分、前後14分、前後3分という時点で追跡した。加えて内受容感覚の正確さおよび敏感さをそれぞれ心拍検出課題とBPQによって測定した。その結果、イベント前後20分、14分においては、時間的ドップラー効果が生じていたほか、内受容感覚においては敏感さ（BPQ）がイベント経験後における、イベントまでの時間的距離の感覚に影響を及ぼしていた。 本発表では実際に経験させたイベントにおける時間的ドップラー効果の存在について、個人の内受容感覚の影響や同時に測定した生理学的指標変動という点を踏まえて、時間的ドップラー効果のメカニズムについて議論する。

近年，AIや仮想技術の進展が著しい。それらの技術により，身体拡張や知覚拡張，メタバースでの交流や様々なVR体験が可能になってきている。ここにきての，ChatGPTの出現で，物事の進み方や社会のあり方が大きく変わる可能性が指摘されている。便利になることへの期待もある一方で，ヒトにとって代わりAIができることが増えていくことへの不安も大きくなっている。既に，インターネットの普及で物事の進み方が加速化し，「自己」が振り回されている感は否めず，急速なこれらの技術の進展により，「自己」が機能不全に陥る可能性が懸念される。人知を超える速さで進展していく社会における「自己」のあり方は，新たな学術的枠組みから，追究していく必要があるのではないかと考え，研究を始めている。本シンポジウムでは，この新たな「自己」研究の可能性を広く議論するため企画した。話題提供では，小林氏が「自己の発達」，梅田氏が「自己の歪み」，杉浦氏が「自己の3側面と“新自己力”」をテーマにそれぞれの知見を紹介する。上原より，新たな「自己」に関する発達理論形成の可能性とその視点からのコメントを行い，その後，全体討論としたい。

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Background: Previous epidemiological and clinical studies have shown that dairy products have beneficial effects on cognitive decline and dementia. Enzymatic digestion of whey protein produces a whey peptide rich in tryptophan-tyrosine-related peptides which improve cognitive performance in mice. We evaluated the effects of whey peptides on cognitive functions in healthy adults in a randomized, double-blind, placebo-controlled design. Methods: 101 healthy adults (45 to 64 years), with a self-awareness of cognitive decline received either whey peptide or placebo supplements for 12 weeks. Changes in cognitive function were assessed using neuropsychological tests at 6 and 12 weeks after the start of supplementation. Results: Verbal fluency test (VFT) score changes tended to be higher in the whey peptide group compared with the placebo at 12 weeks. Subgroup analysis classified by the degree of subjective fatigue showed that changes in the VFT as well as the Stroop and subjective memory function tests between baseline and 6 weeks of intervention were significantly better in subjects with high-level fatigue from the whey peptide group as compared to the placebo group. Conclusions: Intake of whey peptide might improve cognitive function in healthy middle- and older-aged adults with high subjective fatigue levels. Further studies will elucidate the relationship among cognitive improvement, whey peptides, and psychological fatigue.

© 2017 Society of Biological Psychiatry Interoception refers to the process by which the nervous system senses, interprets, and integrates signals originating from within the body, providing a moment-by-moment mapping of the body's internal landscape across conscious and unconscious levels. Interoceptive signaling has been considered a component process of reflexes, urges, feelings, drives, adaptive responses, and cognitive and emotional experiences, highlighting its contributions to the maintenance of homeostatic functioning, body regulation, and survival. Dysfunction of interoception is increasingly recognized as an important component of different mental health conditions, including anxiety disorders, mood disorders, eating disorders, addictive disorders, and somatic symptom disorders. However, a number of conceptual and methodological challenges have made it difficult for interoceptive constructs to be broadly applied in mental health research and treatment settings. In November 2016, the Laureate Institute for Brain Research organized the first Interoception Summit, a gathering of interoception experts from around the world, with the goal of accelerating progress in understanding the role of interoception in mental health. The discussions at the meeting were organized around four themes: interoceptive assessment, interoceptive integration, interoceptive psychopathology, and the generation of a roadmap that could serve as a guide for future endeavors. This review article presents an overview of the emerging consensus generated by the meeting.

Background: Previous epidemiological and clinical studies have shown that dairy products have beneficial effects on cognitive decline and dementia. Enzymatic digestion of whey protein produces a whey peptide rich in tryptophan-tyrosine-related peptides which improve cognitive performance in mice. We evaluated the effects of whey peptides on cognitive functions in healthy adults in a randomized, double-blind, placebo-controlled design. Methods: 101 healthy adults (45 to 64 years), with a self-awareness of cognitive decline received either whey peptide or placebo supplements for 12 weeks. Changes in cognitive function were assessed using neuropsychological tests at 6 and 12 weeks after the start of supplementation. Results: Verbal fluency test (VFT) score changes tended to be higher in the whey peptide group compared with the placebo at 12 weeks. Subgroup analysis classified by the degree of subjective fatigue showed that changes in the VFT as well as the Stroop and subjective memory function tests between baseline and 6 weeks of intervention were significantly better in subjects with high-level fatigue from the whey peptide group as compared to the placebo group. Conclusions: Intake of whey peptide might improve cognitive function in healthy middle- and older-aged adults with high subjective fatigue levels. Further studies will elucidate the relationship among cognitive improvement, whey peptides, and psychological fatigue.

Interoception refers to the process by which the nervous system senses, interprets, and integrates signals originating from within the body, providing a moment-by-moment mapping of the body's internal landscape across conscious and unconscious levels. Interoceptive signaling has been considered a component process of reflexes, urges, feelings, drives, adaptive responses, and cognitive and emotional experiences, highlighting its contributions to the maintenance of homeostatic functioning, body regulation, and survival. Dysfunction of interoception is increasingly recognized as an important component of different mental health conditions, including anxiety disorders, mood disorders, eating disorders, addictive disorders, and somatic symptom disorders. However, a number of conceptual and methodological challenges have made it difficult for interoceptive constructs to be broadly applied in mental health research and treatment settings. In November 2016, the Laureate Institute for Brain Research organized the first Interoception Summit, a gathering of interoception experts from around the world, with the goal of accelerating progress in understanding the role of interoception in mental health. The discussions at the meeting were organized around four themes: interoceptive assessment, interoceptive integration, interoceptive psychopathology, and the generation of a roadmap that could serve as a guide for future endeavors. This review article presents an overview of the emerging consensus generated by the meeting.

This paper reviews the structural specificities and functional roles in Brodmann areas 10 and 38. A number of studies have focused on both areas through various approaches including neuropsychology, neuroimaging, psychiatry, neurology, and neurosurgery. Both areas 10 and 38 may have a substantially very complex higher-order cognitive functions, which are quite hard to disentangle. Here, I picked up some fundamental perspectives for reviewing previous studies, to provide efficient research orientations for the elucidation of functions in both areas.

Although a number of studies have investigated the incongruity-detection and resolution process in humor comprehension, it is difficult to functionally and anatomically dissociate these processes. We used event-related potentials (ERP) and standardized low resolution brain electromagnetic tomography analysis (sLORETA) to examine the time course and localization of brain activity during incongruity detection and resolution. We used the same materials as in our previous fMRI study. Eighteen participants read funny and unfunny scenarios and judged whether the target sentence was funny or not. Results indicated that ERPs elicited by a funny punch line showed a P2 component followed by a P600 component over the centro-parietal electrode sites. Our sLORETA analysis of the P2 ERPs revealed a stronger activation for the funny vs. unfunny condition in the superior frontal gyrus (SFG) and medial prefrontal cortex (mPFC). For the P600 ERPs, the funny punch line elicited greater activation in the temporal-parietal regions. These results indicate that incongruity-detection processes activate the SFG and mPFC in the P2 time window, while incongruity-resolution processes generate activation at the temporal-parietal regions in the P600 time window. These results provide the evidence that verbal humor comprehension is processed in steps which start with the incongruity detection in the early P2 time window and followed by a P600 component reflecting incongruity resolution.

Previous studies on prospective memory (PM), defined as memory for future intentions, suggest that psychological stress enhances successful PM retrieval. However, the mechanisms underlying this notion remain poorly understood. We hypothesized that PM retrieval is achieved through interaction with autonomic nervous activity, which is mediated by the individual accuracy of interoceptive awareness, as measured by the heartbeat detection task. In this study, the relationship between cardiac reactivity and retrieval of delayed intentions was evaluated using the event-based PM task. Participants were required to detect PM target letters while engaged in an ongoing 2-back working memory task. The results demonstrated that individuals with higher PM task performance had a greater increase in heart rate on PM target presentation. Also, higher interoceptive perceivers showed better PM task performance. This pattern was not observed for working memory task performance. These findings suggest that cardiac afferent signals enhance PM retrieval, which is mediated by individual levels of interoceptive accuracy. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’.

Postural tachycardia syndrome (PoTS), a form of dysautonomia, is characterized by orthostatic intolerance, and is frequently accompanied by a range of symptoms including palpitations, lightheadedness, clouding of thought, blurred vision, fatigue, anxiety, and depression. Although the estimated prevalence of PoTS is approximately 5-10 times as common as the better-known condition orthostatic hypotension, the neural substrates of the syndrome are poorly characterized. In the present study, we used magnetic resonance imaging (MRI) with voxel-based morphometry (VBM) applying the diffeomorphic anatomical registration through exponentiated lie algebra (DARTEL) procedure to examine variation in regional brain structure associated with PoTS. We recruited 11 patients with established PoTS and 23 age-matched normal controls. Group comparison of gray matter volume revealed diminished gray matter volume within the left anterior insula, right middle frontal gyrus and right cingulate gyrus in the PoTS group. We also observed lower white matter volume beneath the precentral gyrus and paracentral lobule, right pre- and post-central gyrus, paracentral lobule and superior frontal gyrus in PoTS patients. Subsequent ROI analyses revealed significant negative correlations between left insula volume and trait anxiety and depression scores. Together, these findings of structural differences, particularly within insular and cingulate components of the salience network, suggest a link between dysregulated physiological reactions arising from compromised central autonomic control (and interoceptive representation) and increased vulnerability to psychiatric symptoms in PoTS patients.

This review explores the proposal that vulnerability to psychological symptoms, particularly anxiety, originates in constitutional differences in the control of bodily state, exemplified by a set of conditions that include Joint Hypermobility, Postural Tachycardia Syndrome and Vasovagal Syncope. Research is revealing how brain-body mechanisms underlie individual differences in psychophysiological reactivity that can be important for predicting, stratifying and treating individuals with anxiety disorders and related conditions. One common constitutional difference is Joint Hypermobility, in which there is an increased range of joint movement as a result of a variant of collagen. Joint hypermobility is over-represented in people with anxiety, mood and neurodevelopmental disorders. It is also linked to stress-sensitive medical conditions such as irritable bowel syndrome, chronic fatigue syndrome and fibromyalgia. Structural differences in "emotional" brain regions are reported in hypermobile individuals, and many people with joint hypermobility manifest autonomic abnormalities, typically Postural Tachycardia Syndrome. Enhanced heart rate reactivity during postural change and as recently recognized factors causing vasodilatation (as noted post-prandially, post-exertion and with heat) is characteristic of Postural Tachycardia Syndrome, and there is a phenomenological overlap with anxiety disorders, which may be partially accounted for by exaggerated neural reactivity within ventromedial prefrontal cortex. People who experience Vasovagal Syncope, a heritable tendency to fainting induced by emotional challenges (and needle/blood phobia), are also more vulnerable to anxiety disorders. Neuroimaging implicates brainstem differences in vulnerability to faints, yet the structural integrity of the caudate nucleus appears important for the control of fainting frequency in relation to parasympathetic tone and anxiety. Together there is clinical and neuroanatomical evidence to show that common constitutional differences affecting autonomic responsivity are linked to psychiatric symptoms, notably anxiety.

This review explores the proposal that vulnerability to psychological symptoms, particularly anxiety, originates in constitutional differences in the control of bodily state, exemplified by a set of conditions that include Joint Hypermobility, Postural Tachycardia Syndrome and Vasovagal Syncope. Research is revealing how brainbody mechanisms underlie individual differences in psychophysiological reactivity that can be important for predicting, stratifying and treating individuals with anxiety disorders and related conditions. One common constitutional difference is Joint Hypermobility, in which there is an increased range of joint movement as a result of a variant of collagen. Joint hypermobility is over-represented in people with anxiety, mood and neurodevelopmental disorders. It is also linked to stress-sensitive medical conditions such as irritable bowel syndrome, chronic fatigue syndrome and fibromyalgia. Structural differences in 'emotional' brain regions are reported in hypermobile individuals, and many people with joint hypermobility manifest autonomic abnormalities, typically Postural Tachycardia Syndrome. Enhanced heart rate reactivity during postural change and as recently recognised factors causing vasodilatation (as noted post prandially, post exertion and with heat) is characteristic of Postural Tachycardia Syndrome, and there is a phenomenological overlap with anxiety disorders, which may be partially accounted for by exaggerated neural reactivity within ventromedial prefrontal cortex. People who experience Vasovagal Syncope, a heritable tendency to fainting induced by emotional challenges (and needle/blood phobia), are also more vulnerable to anxiety disorders. Neuroimaging implicates brainstem differences in vulnerability to faints, yet the structural integrity of the caudate nucleus appears important for the control of fainting frequency in relation to parasympathetic tone and anxiety. Together there is clinical and neuroanatomical evidence to show that common constitutional differences affecting autonomic responsivity are linked to psychiatric symptoms, notably anxiety.