2018/02/23 春野

Shared neural coding for social hierarchy and reward value in primate amygdala

Jérôme Munuera, Mattia Rigotti & C. Daniel Salzman
Nat Neurosci. 2018 Mar;21(3):415-423. doi: 10.1038/s41593-018-0082-8.

Abstract

The social brain hypothesis posits that dedicated neural systems process social information. In support of this, neurophysiological data have shown that some brain regions are specialized for representing faces. It remains unknown, however, whether distinct anatomical substrates also represent more complex social variables, such as the hierarchical rank of individuals within a social group. Here we show that the primate amygdala encodes the hierarchical rank of individuals in the same neuronal ensembles that encode the rewards associated with nonsocial stimuli. By contrast, orbitofrontal and anterior cingulate cortices lack strong representations of hierarchical rank while still representing reward values. These results challenge the conventional view that dedicated neural systems process social information. Instead, information about hierarchical rank—which contributes to the assessment of the social value of individuals within a group—is linked in the amygdala to representations of rewards associated with nonsocial stimuli.

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2015/10/14 鮫島

Signatures of Value Comparison in Ventral Striatum Neurons

Caleb E. Strait, Brianna J. Sleezer, Benjamin Y. Hayden
PLoS Biol. 2015 Jun; 13(6): e1002173.

明日は、ちょっと古いですけどHaydenのPlos biologyの論文を中心に、 「価値に基づく意思決定がどこでどのようにおきるか？」について、 またそれを検証する方法について考えたいと思います。

 よろしくお願いします。

Abstract
The ventral striatum (VS), like its cortical afferents, is closely associated with processing of rewards, but the relative contributions of striatal and cortical reward systems remains unclear. Most theories posit distinct roles for these structures, despite their similarities. We compared responses of VS neurons to those of ventromedial prefrontal cortex (vmPFC) Area 14 neurons, recorded in a risky choice task. Five major response patterns observed in vmPFC were also observed in VS: (1) offer value encoding, (2) value difference encoding, (3) preferential encoding of chosen relative to unchosen value, (4) a correlation between residual variance in responses and choices, and (5) prominent encoding of outcomes. We did observe some differences as well; in particular, preferential encoding of the chosen option was stronger and started earlier in VS than in vmPFC. Nonetheless, the close match between vmPFC and VS suggests that cortex and its striatal targets make overlapping contributions to economic choice.

じっさいの実験データも公開されています。

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2014/09/16 菊池

Differential reward coding in the subdivisions of the primate caudate during an oculomotor task
Nakamura K, Santos GS, Matsuzaki R, Nakahara H.
J Neurosci. 2012 Nov 7;32(45):15963-82. 

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2014/06/03 菊池

Dopamine prediction error responses integrate subjective value from different reward dimensions
Armin Lak, William R. Stauffer, and Wolfram Schultz
vol. 111 no. 6 2343–2348 2013

Significance

Most real-world rewards have multiple dimensions, such as amount, risk, and type. Here we show that within a bounded set of such multidimensional rewards monkeys’ choice behavior fulfilled several core tenets of rational choice theory; namely, their choices were stochastically complete and transitive. As such, in selecting between rewards, the monkeys behaved as if they maximized value on a common scale. Dopamine neurons encoded prediction errors that reflected that scale. A particular reward dimension influenced dopamine activity only to the extent that it influenced choice. Thus, vastly different reward types such as juice and food activated dopamine neurons in accordance with subjective value derived from the different rewards. This neuronal signal could serve to update value signals for economic choice.

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2014/05/13 鮫島

Effects of amygdala lesions on reward-value coding in orbital and medial prefrontal cortex
Rudebeck PH, Mitz AR, Chacko RV, Murray EA.
Neuron. 2013 Dec 18;80(6):1519-31. doi: 10.1016/j.neuron.2013.09.036.

[Highlights]
•Neurons in OFC and MFC differentially encode the reward value of stimuli
•Lesions of the amygdala reduce reward coding in OFC but not in MFC
•Amygdala lesions abolish differences between OFC and MFC in reward coding
•Amygdala input is not necessary for reward coding in either OFC or MFC

扁桃体を壊して MFCとOFCの単一細胞記録を解析してわかるvalue codingが変化するかどうか、領域毎に比較している仕事です。
手法的には古いですが、皮質ー皮質下のネットワークがvalue-based decisionさせたときにどう働くのか、考えさせられる仕事だと思います。


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2014/03/14 鮫島

Changing value through cued approach: an automatic mechanism of behavior change
Tom Schonberg, Akram Bakkour, Ashleigh M Hover, Jeanette A Mumford, Lakshya Nagar, Jacob Perez & Russell A Poldrack
Nat Neurosci. 2014 Mar 9. doi: 10.1038/nn.3673.

単純なcue-approachingで value updateがおきちゃいます。という非常にシンプルな話の論文を紹介します。価値の更新はreinforcerやfeedbackによって起きるというのがこれまでの心理・強化学習・経済学での理論で使われていますが、実は他のシンプルな要因によっても価値のupdateが起きてしまうということを新しく示した論文です。過去の経験から対象の価値がどのような変化するのかを考えるのに重要そうな論文ですので紹介させていただきます。

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2013/10/04 鮫島

Distinct Basal Ganglia Circuits Controlling Behaviors Guided by Flexible and Stable Values

Hyoung F Kim & Okihide Hikosaka
Neuron, Volume 79, Issue 5, 1001-1010, 2013

Highlights
► Neurons in the primate caudate nucleus encode reward values of visual objects
► Flexible and stable values are encoded in the caudate head and tail, respectively
► Inactivation of caudate head disrupts gaze choice guided solely by flexible values
► Inactivation of caudate tail disrupts gaze choice guided solely by stable values

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大脳皮質ー基底核ループの並列機能仮説のうち、尾状核の様々ところから記録し、機能としてはcontrolled action と automatic actionという切り口でまとめた論文です。直接choiceの際の活動の詳細な解析はありませんが、object valueや変化の早さという新しい並列性を持ち込んでいます。


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2013/04/26 野々村

The dorsomedial striatum encodes net expected return, critical for energizing performance vigor.
Wang AY, Miura K, Uchida N.
Nat Neurosci. 2013 Apr 14.

ラットのDorsomedial Striatumがresponse vigorを調整すること（action selectionではなく）に重要な役割を果たしていることを主張した論文です．

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2013/03/26 鮫島

Prefrontal and striatal activity related to values of objects and locations.
Kim S, Cai X, Hwang J, Lee D.
Front Neurosci. 2012;6:108.

私の方は、ちょっと古いですが昨年出ているDeayeol Leeラボの論文を紹介します。object value の比較codingがDLPFCとstriatumに少ないけどちゃんとある、という論文です。

よろしくお願いします。

2013/03/18 木村

The primate amygdala combines information about space and value.
Peck CJ, Lau B, Salzman CD.
Nat Neurosci. 2013 Mar;16(3):340-8.

A stimulus predicting reinforcement can trigger emotional responses, such as arousal, and cognitive ones, such as increased attention toward the stimulus. Neuroscientists have long appreciated that the amygdala mediates spatially nonspecific emotional responses, but it remains unclear whether the amygdala links motivational and spatial representations. To test whether amygdala neurons encode spatial and motivational information, we presented reward-predictive cues in different spatial configurations to monkeys and assessed how these cues influenced spatial attention. Cue configuration and predicted reward magnitude modulated amygdala neural activity in a coordinated fashion. Moreover, fluctuations in activity were correlated with trial-to-trial variability in spatial attention. Thus, the amygdala integrates spatial and motivational information, which may influence the spatial allocation of cognitive resources. These results suggest that amygdala dysfunction may contribute to deficits in cognitive processes normally coordinated with emotional responses, such as the directing of attention toward the location of emotionally relevant stimuli.

2013/01/15 春野

How the opinion of others affects our valuation of objects.
Campbell-Meiklejohn DK, Bach DR, Roepstorff A, Dolan RJ, Frith CD.
Curr Biol. 2010 Jul 13;20(13):1165-70.

2012/12/04 山中

Robust representation of stable object values in the oculomotor Basal Ganglia.
Yasuda M, Yamamoto S, Hikosaka O.
J Neurosci. 2012 Nov 21;32(47):16917-32.

大脳基底核の黒質網様部(SNr)が
文脈によって変化するflexibleな価値表現というよりも、
ある程度stableな価値(お金のような?)に基づいた
行動制御により強く関与していることを示しています。

大脳基底核のCaudate tail-SNr-SCという経路が
長期的な価値の計算に重要であることを示唆しています。

関連論文
What and where information in the caudate tail guides saccades to visual objects.
Yamamoto S, Monosov IE, Yasuda M, Hikosaka O.
J Neurosci. 2012 Aug 8;32(32):11005-16.

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Flexible valueのコーディングに
SNr->SCはあまり関与していないのでしょうか？
Sato and Hikosaka(2002)のときに記録したSNｒニューロンと
記録した部位が違う？

あとFig.13Bのchoice rateのプロットは
free-choiceのときのchoice rateを示しているのだとすれば、
(1ブロック30trialでforced trial=24trial,choice trial=6trial)
6trialしかないはずなんですが20~30点くらいあるのはなぜでしょうか？

2012/11/19 鮫島

Transient stimulation of distinct subpopulations of striatal neurons mimics changes in action value.
Tai LH, Lee AM, Benavidez N, Bonci A, Wilbrecht L.
Nat Neurosci. 2012 Sep;15(9):1281-9.


既に皆様読まれているかもしれませんが、光遺伝で一過的にaction valueの増減をmimic したという下記の論文を読んでみたいと思います。

2012/10/09

木村先生

An agent independent axis for executed and modeled choice in medial prefrontal cortex.
Nicolle A, Klein-Flügge MC, Hunt LT, Vlaev I, Dolan RJ, Behrens TE.
Neuron. 2012 Sep 20;75(6):1114-21.

　＊

渡邊さん

Subcortical connections to human amygdala and changes following destruction of the visual cortex.
Tamietto M, Pullens P, de Gelder B, Weiskrantz L, Goebel R.
Curr Biol. 2012 Aug 7;22(15):1449-55.

Emotion processing and the amygdala: from a 'low road' to 'many roads' of evaluating biological significance.
Pessoa L, Adolphs R.
Nat Rev Neurosci. 2010 Nov;11(11):773-83.

2012/07/02 榎本

Learning to simulate others' decisions.
Suzuki S, Harasawa N, Ueno K, Gardner JL, Ichinohe N, Haruno M, Cheng K, Nakahara H.
Neuron. 2012 Jun 21;74(6):1125-37.

プレスリリース

おめでとうございます。

2012/03/05 榎本

榎本

Modulation of value representation by social context in the primate orbitofrontal cortex.
Azzi JC, Sirigu A, Duhamel JR.
Proc Natl Acad Sci U S A. 2012 Feb 7;109(6):2126-31.

さる三頭！