一般口演
意思決定
Decision Making
座長：竹内 雄一（北海道大学薬学研究院薬理学研究室） |
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| 2022年6月30日 15:00～15:15 沖縄コンベンションセンター 会議場B2 第5会場
1O05a2-01
反復社会的敗北ストレスがマウスの報酬獲得意欲に与える影響
Effects of social defeat stress on effort-based decision making
*西 真弓(1)、遠藤 のぞみ(1)、杣山 奈実(1)
1. 奈良県立医科大学
*Mayumi Nishi(1), Nozomi Endo(1), Nami Somayama(1)
1. Nara Medical University
Keyword: social defeat stress, decision making, nucleus accumbens, dopamine receptor
Stress is a major risk factor for the development of psychiatric disorders such as depression, anxiety, and post-traumatic stress disorder. Repeated social defeat stress (RSDS) is commonly employed as an ethologically relevant stressor in rodents. Recently, many studies have shown that the RSDS affects depressive- and anxiety-like behaviors that strongly affect motivation. We examined motivation related to reward acquisition in RSDS mice by using our original effort-based decision-making test . RSDS mice that exhibited 40% or more social avoidance ratio were employed in subsequent behavioral tests. In the effort-based decision-making test, chocolate as a high-reward and food pellet as a low-reward were placed in each side of the experimental box. A high wall was set upped as a high-cost in front of the chocolate reward, while a low wall was set upped as a low-cost in front of the food pellet reward. Mice were allowed to freely select either high-reward/high-cost or low-reward/low-cost option. Control mice mostly selected high-reward/high-cost option. Contrary, RSDS mice were divided into two groups; RSDS mice that chose the comparable percent of high-reward/high-cost option as with control mice and RSDS mice that did not absolutely choose high-reward/high-cost option. Importantly, even RSDS mice that only chose low-reward/low-cost option remained ability to overcome the high wall. Then, we investigated the gene expression level in the reward-related brain regions by using RNA-Seq and found that the expression level of Drd1 gene was significantly reduced in the nucleus accumbens (NAc) of the group choosing low-reward/low-cost option as compared with high-reward/high-cost option group. These findings suggest that DRD1 expressing neurons in the NAc are involved in the “decline of motivation” due to RSDS. We are now analyzing the effects of DRD1 agonist and antagonist on effort-based decision-making behavior. | | 2022年6月30日 15:15～15:30 沖縄コンベンションセンター 会議場B2 第5会場
1O05a2-02
認知的な努力コストの予測の更新には実際に努力を行使する必要があり、認知的な努力コストの適応的な学習は時間差学習に従わない
Updates of the Expected Cost of Mental Effort Would Need Actual Effort Exertion and Adaptive Learning of Mental Effort Cost Would Not Follow Temporal-Difference Learning
*永瀬 麻子(1,2,3,4)、小野田 慶一(4,6)、森田 賢治(3,5)、川越 敏和(7)、山口 修平(4,8)、花島 律子(2)、赤石 れい(9)
1. 日本学術振興会特別研究員-PD、2. 鳥取大学医学部脳神経内科、3. 東京大学大学院教育学研究科身体教育学コース、4. 島根大学医学部内科学第三、5. 東京大学ニューロインテリジェンス国際研究機、6. 追手門学院大学心理学部心理学科、7. 東海大学文理融合学部、8. 島根県立中央病院、9. 理研CBS－トヨタ連携センター社会価値意思決定
*Asako Mitsuto Nagase(1,2,3,4), Keiichi Onoda(4,6), Kenji Morita(3,5), Toshikazu Kawagoe(7), Shuhei Yamaguchi(4,8), Ritsuko Hanajima(2), Rei Akaishi(9)
1. JSPS Research Fellow-PD, 2. Dept Brain and Neurosci, Tottori Univ, 3. Dept of Physical and Health Education, Grad Sch of Education, Univ of Tokyo, 4. Dept Neurol, Shimane Univ, 5. WPI-IRCN, Univ of Tokyo, 6. Faculty of Psychology, Otemon Gakuin Univ, 7. Liberal Arts Edu Center, Tokai Univ, 8. Shimane Hospital Bureau, 9. Center for Brain Science, RIKEN
Keyword: mental effort, frontal cortex, striatum, decision making and learning
Humans make a choice by balancing effort-cost and benefit in an uncertain world, but little is known of where the cost-benefit information comes from. The reward-learning mechanisms are thought to follow temporal-difference (TD) learning, which uses two predictions temporally different. While the cost-learning mechanisms of mental effort are unclear. Previous studies suggested that most humans avoid mental effort, representing the expected cost of mental effort and cost prediction error (CPE) in dorsomedial frontal cortex/dorsal anterior cingulate cortex (dmFC/dACC) and other regions. We initially hypothesized that the cost learning of mental effort follows TD learning and that the cue information of upcoming effort levels would update the expected cost. We predicted that at informative-cue timing, CPE would be correlated with the activity in dmFC/dACC positively and in striatum negatively. We conducted two fMRI experiments of demand-selection tasks with the informative cues for healthy subjects, using mental division and cube-folding problems (Exp. 1: n=30, Exp. 2: n=28). In a trial, subjects chose an option from two and solved a problem. The upcoming effort levels of each option were high or low and changed over time. We presented the informative cues which were 100% associated with upcoming effort levels between choice options and problems. We conducted the model-based fMRI analysis with a reinforcement learning model based on effort levels and the conjunction analysis among Exp. 1 and 2 for subjects who avoided higher effort, answered correctly over a criterion, and moved heads under a criterion (Exp. 1, n=25; Exp. 2, n=. 23). However, at informative-cue timing, we did not find the activity in the dmFC/dACC and striatum which was correlated with CPE. This result did not support the initial hypothesis. Therefore, we formulated two alternative hypotheses that either effort initiation or completion updates the expected cost. At effort-initiation timing, the activity of the orbitofrontal cortex/ventromedial prefrontal cortex/ventral ACC was positively correlated with CPE. At effort-completion timing, CPE was correlated with the activity in the dmFC/dACC positively and the bilateral caudate negatively. Our results suggest that human brains represent CPE during effort exertion, not at informative-cue timing. We propose that the adaptive learning of mental effort cost does not follow TD learning and that update of the expected cost needs effort exertion. | | 2022年6月30日 15:30～15:45 沖縄コンベンションセンター 会議場B2 第5会場
1O05a2-03
前部帯状回‐運動皮質回路は多段階の意思決定において動的にルール表現を符号化する
Dynamical encoding of rule representations in cingulate-motor circuits for sequential choice decisions
*竹内 大吾(1,4,5)、Dheeraj Roy(2,5)、Shruti Muralidhar(1,5)、Takashi Kawai(1,5)、Andrea Bari(1,5)、Chanel Lovett(4)、Heather A Sullivan(3)、Ian R Wickersham(3)、Susumu Tonegawa(1,4,5)
1. マサチューセッツ工科大学、2. ブロード研究所、3. マクガヴァン研究所、4. ハワードヒューズ医学研究所、5. 理研MIT神経回路遺伝学センター
*Daigo Takeuchi(1,4,5), Dheeraj Roy(2,5), Shruti Muralidhar(1,5), Takashi Kawai(1,5), Andrea Bari(1,5), Chanel Lovett(4), Heather A Sullivan(3), Ian R Wickersham(3), Susumu Tonegawa(1,4,5)
1. Massachusetts Institute of Technology, 2. Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, 3. McGovern Institute for Brain Research at MIT, 4. Howard Hughes Medical Institute at MIT, 5. RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory
Keyword: SEQUENTIAL DECISION MAKING, ANTERIOR CINGULATE CORTEX, MOTOR CORTEX , OUTCOME
Anterior cingulate cortex mediates the flexible updating of an animal’s choice responses upon rule changes in the environment. However, how anterior cingulate cortex entrains motor cortex to reorganize rule representations and generate required motor outputs remains unclear. Here, we demonstrate that chemogenetic silencing of the terminal projections of cingulate cortical neurons in secondary motor cortex disrupted sequential choice performance in trials immediately following rule switches, suggesting that these inputs are necessary to update rule representations for choice decisions stored in the motor cortex. Indeed, the silencing of cingulate cortex decreased rule selectivity of secondary motor cortical neurons. Furthermore, optogenetic silencing of cingulate cortical neurons that was temporally targeted to error trials immediately after rule switches exacerbated errors in the following trials. These results suggest that cingulate cortex monitors behavioral errors and update rule representations in motor cortex, revealing a critical role for cingulate-motor circuits in adaptive choice behaviors. | | | |
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