研究者詳細 - 大平　英樹

Effects of emotional context during encoding: An advantage for negative context in immediate recognition and positive context in delayed recognition. 査読有り

Toyama,A., Katsuhara,M., Sakurai,Y., & Ohira,H.

Psychology 5 巻 ( 9 ) 頁： 994-1000 2014年7月

Effects of emotional context during encoding: An advantage for negative context in immediate recognition and positive context in delayed recognition. 査読有り

Toyama,A, Katsuhara,M, Sakurai,Y, Ohira,H

Psychology 5 巻 ( 9 ) 頁： 994-1000 2014年7月

感情的意思決定を支える脳と身体の機能的関連査読有り

大平英樹

心理学評論 57 巻頁： 94-119 2014年6月

感情的意思決定を支える脳と身体の機能的関連査読有り

大平英樹

心理学評論 57 巻頁： 94-119 2014年6月

Attenuated right ventricular energetics evaluated using <sup>11</sup>C-acetate PET in patients with pulmonary hypertension

Yoshinaga K., Ohira H., Tsujino I., Oyama-Manabe N., Mielniczuk L., Beanlands R.S.B., Katoh C., Kasai K., Manabe O., Sato T., Fujii S., Ito Y.M., Tomiyama Y., Nishimura M., Tamaki N.

European Journal of Nuclear Medicine and Molecular Imaging 41 巻 ( 6 ) 頁： 1240 - 1250 2014年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：European Journal of Nuclear Medicine and Molecular Imaging

Purpose: The right ventricle (RV) has a high capacity to adapt to pressure or volume overload before failing. However, the mechanisms of RV adaptation, in particular RV energetics, in patients with pulmonary hypertension (PH) are still not well understood. We aimed to evaluate RV energetics including RV oxidative metabolism, power and efficiency to adapt to increasing pressure overload in patients with PH using 11C-acetate PET. Methods: In this prospective study, 27 patients with WHO functional class II/III PH (mean pulmonary arterial pressure 39.8±13.5 mmHg) and 9 healthy individuals underwent 11C-acetate PET. 11C-acetate PET was used to simultaneously measure oxidative metabolism (k mono) for the left ventricle (LV) and RV. LV and RV efficiency were also calculated. Results: The RV ejection fraction in PH patients was lower than in controls (p=0.0054). There was no statistically significant difference in LV k mono (p=0.09). In contrast, PH patients showed higher RV k mono than did controls (0.050±0.009 min-1 vs. 0.030±0.006 min-1, p<0.0001). PH patients exhibited significantly increased RV power (p<0.001) and hence increased RV efficiency compared to controls (0.40±0.14 vs. 0.017±0.12 mmHg·mL·min/g, p=0.001). Conclusion: The RV oxidative metabolic rate was increased in patients with PH. Patients with WHO functional class II/III PH also had increased RV power and efficiency. These findings may indicate a myocardial energetics adaptation response to increasing pulmonary arterial pressure. © 2014 Springer-Verlag Berlin Heidelberg.

DOI： 10.1007/s00259-014-2736-4

Scopus

INFLUENCES OF SOCIOECONOMIC STATUS ON FUNCTIONAL BRAIN-BODY ASSOCIATION IN DECISION-MAKING

Ohira Hideki, Matsunaga Masahiro, Yamakawa Kaori, Toyama Asako

PSYCHOSOMATIC MEDICINE 76 巻 ( 3 ) 頁： A32 - A32 2014年4月

島の機能と自己感査読有り

大平英樹

Brain and Nerve 66 巻頁： 417-427 2014年

意思決定と島の機能査読有り

大平英樹

神経心理学 30 巻頁： 11-18 2014年

Dual learning processes underlying human decision-making in reversal learning tasks: functional significance and evidence from the model fit to human behavior.

Bai Y, Katahira K, Ohira H

Frontiers in psychology 5 巻 ( AUG ) 頁： 871 2014年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Frontiers in Psychology

Humans are capable of correcting their actions based on actions performed in the past, and this ability enables them to adapt to a changing environment. The computational field of reinforcement learning (RL) has provided a powerful explanation for understanding such processes. Recently, the dual learning system, modeled as a hybrid model that incorporates value update based on reward-prediction error and learning rate modulation based on the surprise signal, has gained attention as a model for explaining various neural signals. However, the functional significance of the hybrid model has not been established. In the present study, we used computer simulation in a reversal learning task to address functional significance in a probabilistic reversal learning task. The hybrid model was found to perform better than the standard RL model in a large parameter setting. These results suggest that the hybrid model is more robust against the mistuning of parameters compared with the standard RL model when decision-makers continue to learn stimulus-reward contingencies, which can create abrupt changes. The parameter fitting results also indicated that the hybrid model fit better than the standard RL model for more than 50% of the participants, which suggests that the hybrid model has more explanatory power for the behavioral data than the standard RL model. © 2014 Bai, Katahira and Ohira.

DOI： 10.3389/fpsyg.2014.00871

Web of Science

Scopus

PubMed

Neural and sympathetic activity associated with exploration in decision-making: further evidence for involvement of insula.

Ohira H, Ichikawa N, Kimura K, Fukuyama S, Shinoda J, Yamada J

Frontiers in behavioral neuroscience 8 巻 ( November ) 頁： 381 - 12 2014年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Frontiers in Behavioral Neuroscience

We previously reported that sympathetic activity was associated with exploration in decision-making indexed by entropy, which is a concept in information theory and indexes randomness of choices or the degree of deviation from sticking to recent experiences of gains and losses, and that activation of the anterior insula mediated this association. The current study aims to replicate and to expand these findings in a situation where contingency between options and outcomes is manipulated. Sixteen participants performed a stochastic decision-making task in which we manipulated a condition with low uncertainty of gain/loss (contingent-reward condition) and a condition with high uncertainty of gain/loss (random-reward condition). Regional cerebral blood flow was measured by 15O-water positron emission tomography (PET), and cardiovascular parameters and catecholamine in the peripheral blood were measured, during the task. In the contingent-reward condition, norepinephrine as an index of sympathetic activity was positively correlated with entropy indicating exploration in decision-making. Norepinephrine was negatively correlated with neural activity in the right posterior insula, rostral anterior cingulate cortex, and dorsal pons, suggesting neural bases for detecting changes of bodily states. Furthermore, right anterior insular activity was negatively correlated with entropy, suggesting influences on exploration in decision-making. By contrast, in the random-reward condition, entropy correlated with activity in the dorsolateral prefrontal and parietal cortices but not with sympathetic activity. These findings suggest that influences of sympathetic activity on exploration in decision-making and its underlying neural mechanisms might be dependent on the degree of uncertainty of situations.

DOI： 10.3389/fnbeh.2014.00381

<大平 英樹>

論文 - 大平 英樹

<大平　英樹>

論文 - 大平　英樹