2012年4月28日土曜日

表参道「よろにく」(高級感と緊張感漂う絶品焼肉)


GW初日は某件のお祝い。
美味しいお肉を食べよう!
ということで、知る人ぞ知る表参道の名店「よろしいお肉」こと「よろにく」へ。
http://r.tabelog.com/tokyo/A1306/A130602/13042979/

店構えは隠れが風。
ものすごく雰囲気の良いお店で、普段は「年配(壮年?)男性と着飾った女性」という関係不明な怪しい組み合わせが多いとの噂だが、休日だったのでファミリーがほとんど(残念…:笑)。

そしてなんと言ってもこのお店の一番の特徴は、
コース料理で色んなお肉を「店員さんが一枚一枚焼いてくれる」こと!
店員さんはこちらが若干引くくらい真剣に温度とタイミングを計って焼いてくれます。
そのせいか、仕上がりは最高なんですが、食卓にはなんとも言えない緊張感が(汗)。
いや、しつこいですが、仕上がりは最高なんですよ。

焼いてくれるのはアイドル並みの美人店員さんという噂もあったのですが、我々のテーブルにはチーフっぽいお兄さんがついてくれました。これも残念…。
注:他のアイドル店員さん達を指導していたので腕はピカ一だと思われます。また、お肉への情熱・語りも接客も一流でした。ただ一点!女性でもなければアイドル顔でもありませんでした(笑)。

注文したのは9000円のコース。
怒濤の肉攻めでした(法規制で生肉が食べられなかったのが残念…)。

まずはお通し・キムチ・ナムルに続き、「ヒレ」。
軽く炙った程度でものすごく柔らかい!なんですか、これは?
これからの期待が膨らみます。

次は、「イチボ」に「白センマイ」。
イチボはローストビーフ風に軽く(あくまで軽く)火を通した後、生卵&タレと絡めて「ユッケ風」に仕上げ。
蕩けそうに美味しかった…

そしてサラダを挟んで、「ハツ」、「タン」、「ハラミ」。
どれもサクっと噛み切れるほどの柔らかさ。
普段は内蔵系はあまり食べないのだけど、ハツにも感動。
店員さん曰く「火を通しすぎないのがコツ(もちろん新鮮なお肉に限る)。火を通しすぎると固く臭くなる」とのことでした。

続いては、「カタサンカク」と「シャトーブリアン」。
「シャトーブリアンはヒレ肉の一部なんですよ」という店員さんの蘊蓄に「へ〜」。
(店員さんともだいぶ打ち解けて緊張感も薄れてきました)

その後、お口直しのお吸い物を挟んで、いよいよ脂の乗った霜降りコース。
一番手は、「ミスジ」と「シルクロース」。
「ミスジって最近よく聞きますが、昔はなかったんですか?」と質問。
店員さんから「昔はロースと区別してなかったのですが、ジャンボという焼肉店が注目して広まったんですよ」という蘊蓄と「最高でも二口以内で食べて下さい(ちまちま食べるのはNG)」という不思議な要望をもらって、二口でぺろり。
(貧乏性なので一口はもったいないと思ってしまった…)
そして、一番人気らしい、シルクロース(ちなみに「シルク」の部分はよろにくの造語とのこと)。
甘めタレをじゃぶじゃぶつけた後、ご飯に包んで食べる。最高〜。


お肉の最後は「サーロイン(厚切りステーキ風)」と「ザブトン」。
サーロインは歯がなくても噛み切れるほどの柔らかさ。ほんま最高〜。
ザブトンは卵黄につけてすき焼き風にいただく。これまた柔らかくて有頂天〜。
これでお肉は終わり。

個人的には、後半の霜降りシリーズも良いですが、前半の「ヒレ・シリーズ」に痺れました!

締めは「素麺」に「デザート」。
デザートは「ほうじ茶かき氷」と「しろくま」をサービスしてもらって大満足。
さすがに有名高級店。
上質なお肉とサービスをこころゆくまで堪能しました。
また来たいです。
そのためには「先立つものが…」ですが、「奢ってあげたい」という人はぜひご連絡を!

2012年4月26日木曜日

When Are Two Heads Better than One and Why?


Asher Koriat
Science 20 April 2012: Vol. 336 no. 6079 pp. 360-362

A recent study, using a perceptual task, indicated that two heads were better than one provided that the members could communicate freely, presumably sharing their confidence in their judgments. Capitalizing on recent work on subjective confidence, I replicated this effect in the absence of any dyadic interaction by selecting on each trial the decision of the more confident member of a virtual dyad. However, because subjective confidence monitors the consensuality rather than the accuracy of a decision, when most participants were in error, reliance on the more confident member yielded worse decisions than those of the better individual. Assuming that for each issue group decisions are dominated by the more confident member, these results help specify when groups will be more or less accurate than individuals.

Multiple dynamic representations in the motor cortex during sensorimotor learning


D. Huber , D. A. Gutnisky , S. Peron , D. H. O|[rsquo]|Connor , J. S. Wiegert , L. Tian , T. G. Oertner , L. L. Looger & K. Svoboda
Nature 484, 473–478 (26 April 2012)

The mechanisms linking sensation and action during learning are poorly understood. Layer 2/3 neurons in the motor cortex might participate in sensorimotor integration and learning; they receive input from sensory cortex and excite deep layer neurons, which control movement. Here we imaged activity in the same set of layer 2/3 neurons in the motor cortex over weeks, while mice learned to detect objects with their whiskers and report detection with licking. Spatially intermingled neurons represented sensory (touch) and motor behaviours (whisker movements and licking). With learning, the population-level representation of task-related licking strengthened. In trained mice, population-level representations were redundant and stable, despite dynamism of single-neuron representations. The activity of a subpopulation of neurons was consistent with touch driving licking behaviour. Our results suggest that ensembles of motor cortex neurons couple sensory input to multiple, related motor programs during learning.

2012年4月25日水曜日

Serotonin Selectively Modulates Reward Value in Human Decision-Making


Ben Seymour, Nathaniel D. Daw, Jonathan P. Roiser, Peter Dayan, and Ray Dolan
J. Neurosci. 2012;32 5833-5842
http://www.jneurosci.org/cgi/content/abstract/32/17/5833?etoc

Establishing a function for the neuromodulator serotonin in human decision-making has proved remarkably difficult because if its complex role in reward and punishment processing. In a novel choice task where actions led concurrently and independently to the stochastic delivery of both money and pain, we studied the impact of decreased brain serotonin induced by acute dietary tryptophan depletion. Depletion selectively impaired both behavioral and neural representations of reward outcome value, and hence the effective exchange rate by which rewards and punishments were compared. This effect was computationally and anatomically distinct from a separate effect on increasing outcome-independent choice perseveration. Our results provide evidence for a surprising role for serotonin in reward processing, while illustrating its complex and multifarious effects.

Social Interaction Enhances Motor Resonance for Observed Human Actions


Jeremy Hogeveen and Sukhvinder S. Obhi
J. Neurosci. 2012;32 5984-5989
http://www.jneurosci.org/cgi/content/abstract/32/17/5984?etoc

Understanding the neural basis of social behavior has become an important goal for cognitive neuroscience and a key aim is to link neural processes observed in the laboratory to more naturalistic social behaviors in real-world contexts. Although it is accepted that mirror mechanisms contribute to the occurrence of motor resonance (MR) and are common to action execution, observation, and imitation, questions remain about mirror (and MR) involvement in real social behavior and in processing nonhuman actions. To determine whether social interaction primes the MR system, groups of participants engaged or did not engage in a social interaction before observing human or robotic actions. During observation, MR was assessed via motor-evoked potentials elicited with transcranial magnetic stimulation. Compared with participants who did not engage in a prior social interaction, participants who engaged in the social interaction showed a significant increase in MR for human actions. In contrast, social interaction did not increase MR for robot actions. Thus, naturalistic social interaction and laboratory action observation tasks appear to involve common MR mechanisms, and recent experience tunes the system to particular agent types.

Localized microstimulation of primate pregenual cingulate cortex induces negative decision-making


Ken-ichi Amemori & Ann M Graybiel
Nature Neuroscience 15, 776–785 (2012)

The pregenual anterior cingulate cortex (pACC) has been implicated in human anxiety disorders and depression, but the circuit-level mechanisms underlying these disorders are unclear. In healthy individuals, the pACC is involved in cost-benefit evaluation. We developed a macaque version of an approach-avoidance decision task used to evaluate anxiety and depression in humans and, with multi-electrode recording and cortical microstimulation, we probed pACC function as monkeys performed this task. We found that the macaque pACC has an opponent process-like organization of neurons representing motivationally positive and negative subjective value. Spatial distribution of these two neuronal populations overlapped in the pACC, except in one subzone, where neurons with negative coding were more numerous. Notably, microstimulation in this subzone, but not elsewhere in the pACC, increased negative decision-making, and this negative biasing was blocked by anti-anxiety drug treatment. This cortical zone could be critical for regulating negative emotional valence and anxiety in decision-making.

Mapping value based planning and extensively trained choice in the human brain


Klaus Wunderlich, Peter Dayan & Raymond J Dolan
Nature Neuroscience 15, 786–791 (2012)

Investigations of the underlying mechanisms of choice in humans have focused on learning from prediction errors, leaving the computational structure of value based planning comparatively underexplored. Using behavioral and neuroimaging analyses of a minimax decision task, we found that the computational processes underlying forward planning are expressed in the anterior caudate nucleus as values of individual branching steps in a decision tree. In contrast, values represented in the putamen pertain solely to values learned during extensive training. During actual choice, both striatal areas showed a functional coupling to ventromedial prefrontal cortex, consistent with this region acting as a value comparator. Our findings point toward an architecture of choice in which segregated value systems operate in parallel in the striatum for planning and extensively trained choices, with medial prefrontal cortex integrating their outputs.

2012年4月24日火曜日

Neural basis of egalitarian behavior


Christopher T. Dawes, Peter John Loewen, Darren Schreiber, Alan N. Simmons, Taru Flagan, Richard McElreath, Scott E. Bokemper, James H. Fowler, and Martin P. Paulus
PNAS April 24, 2012 vol. 109 no. 17 6479-6483

fMRI研究。「平等指向」と「Insulaの活動」は正の(被験者間)相関がある。Insulaの活動は「ランダム所得ゲームでの行動」、「自己申告」、「独裁者ゲームでの行動」、全てと相関する。 http://www.pnas.org/content/early/2012/04/05/1118653109

Individuals are willing to sacrifice their own resources to promote equality in groups. These costly choices promote equality and are associated with behavior that supports cooperation in humans, but little is known about the brain processes involved. We use functional MRI to study egalitarian preferences based on behavior observed in the “random income game.” In this game, subjects decide whether to pay a cost to alter group members’ randomly allocated incomes. We specifically examine whether egalitarian behavior is associated with neural activity in the ventromedial prefrontal cortex and the insular cortex, two regions that have been shown to be related to social preferences. Consistent with previous studies, we find significant activation in both regions; however, only the insular cortex activations are significantly associated with measures of revealed and expressed egalitarian preferences elicited outside the scanner. These results are consistent with the notion that brain mechanisms involved in experiencing the emotional states of others underlie egalitarian behavior in humans.

Activation of VTA GABA Neurons Disrupts Reward Consumption.


van Zessen R, Phillips JL, Budygin EA, Stuber GD.
Neuron. 2012 Mar 22;73(6):1184-94. Epub 2012 Mar 21.

古典的条件づけとオプトジェネティクス。VTA・GABAニューロンを活性化させると、「報酬手掛かりへの反応(licking頻度)」は変わらないが、報酬そのものへの反応は変わる(頻度減少)。また、VTA・側座核のドーパミン放出が抑制される。 http://www.ncbi.nlm.nih.gov/pubmed/22445345

The activity of ventral tegmental area (VTA) dopamine (DA) neurons promotes behavioral responses to rewards and environmental stimuli that predict them. VTA GABA inputs synapse directly onto DA neurons and may regulate DA neuronal activity to alter reward-related behaviors; however, the functional consequences of selective activation of VTA GABA neurons remains unknown. Here, we show that in vivo optogenetic activation of VTA GABA neurons disrupts reward consummatory behavior but not conditioned anticipatory behavior in response to reward-predictive cues. In addition, direct activation of VTA GABA projections to the nucleus accumbens (NAc) resulted in detectable GABA release but did not alter reward consumption. Furthermore, optogenetic stimulation of VTA GABA neurons directly suppressed the activity and excitability of neighboring DA neurons as well as the release of DA in the NAc, suggesting that the dynamic interplay between VTA DA and GABA neurons can control the initiation and termination of reward-related behaviors.

2012年4月22日日曜日

ミスチル・ライブ@西武ドーム MR.CHILDREN TOUR POPSAURUS 2012


行ってきました!
ミスチル・ライブ@西武ドーム。
(セット・リストとか有益な情報はありません。というか覚えてない…)

前々日に主催者から、
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西武ドームはオープンエアーの会場となり、ドーム内の気温は野外と同じです。
特に夜間は冷え込みますので、防寒具を必ずお持ちください。
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とメール。
当日昼には「だめ押し」で、
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昨日も公演が開催されましたが、来場されたお客様も想像以上の寒さに驚いておりました。
冬物のダウンジャケット等でも問題ないくらいの寒さなので、万全の対策でライブをお楽しみください。
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とメール。

「しつこいねん(笑)!」と思いつつ超厚着で出陣。
内訳は下から:
・靴下二枚重ね
・ヒートテックパッチ(タイツ)
・ジーンズ
・ヒートテックTシャツ二枚重ね
・タートルネックセーター
・シャツ
・ウインドウブレーカー
・コート
・マフラー
・軍手
・腰、靴下にカイロ
一月の北海道出張を完全に超えた…そして、着膨れのせいで腕が肩より上には上がらず…
でも本当に寒かったので、このアナウンスには感謝!!

駅を出てすぐの会場前には「宣伝カー?」や「歴代アルバムジャケットのパネル」が飾ってあり、盛り上がってきました。

そして忘れてはいけないのが、会場待ちの間に食べた「築地・銀だこ」。
寒い中食べて、めっちゃ美味しかった。最高でした。
これだけで行った甲斐がありました(ウソです:笑)。

そして肝心のライブ本番。
同行者がトイレ待ちで「開演直前」に到着というハプニング(もうオープニング映像始まってた:汗)もありつつ、無事に開始!

座席はアリーナ41列目とグッド・ポジション。
(途中の数曲の間、メンバー全員が花道で演奏してて、その間はかなり近かったです)
ノリノリのお姉さん(と言いつつたぶん年下)や「桜井さ〜ん!」と絶叫する女の子も居て、なかなかカオスでした。

印象に残ったのは一曲目の「エソラ」。
正直言って、2000年代後半の曲はあまり馴染みがないのだけど、すごい良くて盛り上がりました(オープニングにぴったり)!
そして、鉄板は「innocent world」。
ライブでは盛り上がる曲ですし、90年代に中高時代を過ごした30代にはこたえられません。
「受験勉強しながら聞いてたなあ」とか、少しだけ(あくまで少しだけ)、当時を思い出しました。
あと、「ニシエヒガシエ」の桜井さんのダンスはキュートで印象に残りましたね(笑)。

とっても楽しく、ミスチル・ワールド堪能しました!
とはいえ、寒い中で立ちっぱなし、西武ドームのアクセスの悪さ(自宅から近いけど、付近の駅が一つだけ、かつ、電車本数も少ないorz)で、おっさんは疲れました。
でも、また行きたい(できれば暖かい時期に:笑)!

2012年4月19日木曜日

Learning and Generalization under Ambiguity: An fMRI Study


J R Chumbley, G Flandin, D R Bach, J Daunizeau, E Fehr, R J Dolan, and K J Friston
PLoS Comput Biol, 2012 vol. 8 (1) p. e1002346

「般化(過去の学習結果を新しい状況に応用する)」のfMRI研究。実験では「般化可能な状況」と「不可能な状況」が交互に出てくる。被験者は「(どの程度)般化できるのか否か」をベイズ的に学習。また、その「程度」は海馬に保持されている。 http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1002346

Adaptive behavior often exploits generalizations from past experience by applying them judiciously in new situations. This requires a means of quantifying the relative importance of prior experience and current information, so they can be balanced optimally. In this study, we ask whether the brain generalizes in an optimal way. Specifically, we used Bayesian learning theory and fMRI to test whether neuronal responses reflect context-sensitive changes in ambiguity or uncertainty about experience-dependent beliefs. We found that the hippocampus expresses clear ambiguity-dependent responses that are associated with an augmented rate of learning. These findings suggest candidate neuronal systems that may be involved in aberrations of generalization, such as over-confidence.

2012年4月18日水曜日

The Known Unknowns: Neural Representation of Second-Order Uncertainty, and Ambiguity


リスクと不確実性下の意思決定。不確実性は後部帯状皮質で保持されている。報酬確率(リスク)と不確実性(リスクについてのリスク)を独立に変動させられるタスクを開発したのがポイント。 http://www.jneurosci.org/content/31/13/4811

Dominik R Bach, Oliver Hulme, William D Penny, and Raymond J Dolan
Journal of Neuroscience
2011 vol. 31 (13) pp. 4811-4820

Predictions provided by action-outcome probabilities entail a degree of (first-order) uncertainty. However, these probabilities themselves can be imprecise and embody second-order uncertainty. Tracking second-order uncertainty is important for optimal decision making and reinforcement learning. Previous functional magnetic resonance imaging investigations of second-order uncertainty in humans have drawn on an economic concept of ambiguity, where action-outcome associations in a gamble are either known (unambiguous) or completely unknown (ambiguous). Here, we relaxed the constraints associated with a purely categorical concept of ambiguity and varied the second-order uncertainty of gambles continuously, quantified as entropy over second-order probabilities. We show that second-order uncertainty influences decisions in a pessimistic way by biasing second-order probabilities, and that second-order uncertainty is negatively correlated with posterior cingulate cortex activity. The category of ambiguous (compared with nonambiguous) gambles also biased choice in a similar direction, but was associated with distinct activation of a posterior parietal cortical area; an activation that we show reflects a different computational mechanism. Our findings indicate that behavioral and neural responses to second-order uncertainty are distinct from those associated with ambiguity and may call for a reappraisal of previous data.

Controlling Human Striatal Cognitive Function via the Frontal Cortex


Martine R. van Schouwenburg, Jacinta O'Shea, Rogier B. Mars, Matthew F. S. Rushworth, and Roshan Cools
J. Neurosci. 2012;32 5631-5637
http://www.jneurosci.org/cgi/content/abstract/32/16/5631?etoc

Cognitive flexibility is known to depend on the striatum. However, the striatum does not act in isolation to bias cognitive flexibility. In particular, cognitive flexibility also implicates the frontal cortex. Here we tested the hypothesis that the human frontal cortex controls cognitive flexibility by regulating striatal function via topographically specific frontostriatal connections. To this end, we exploited a repetitive transcranial magnetic stimulation (TMS) protocol over frontal cortex that is known to increase dopamine release in the striatum. This intervention was combined with functional magnetic resonance imaging to determine the functional and topographic specificity of its consequences at the whole brain level. Participants were scanned both before and after off-line TMS while performing a cognitive switching task that is known to depend on a specific striatal substructure, the putamen. Frontal stimulation perturbed task-specific functional signals in the putamen, while reducing fronto-striatal functional connectivity. There were no such effects of TMS over the medial parietal cortex. These data strengthen the hypothesis that cognitive flexibility involves topographic frontal control of striatal function.

Social-Cognitive Deficits in Normal Aging


Joseph M. Moran, Eshin Jolly, and Jason P. Mitchell
J. Neurosci. 2012;32 5553-5561
http://www.jneurosci.org/cgi/content/abstract/32/16/5553?etoc

A sizeable number of studies have implicated the default network (e.g., medial prefrontal and parietal cortices) in tasks that require participants to infer the mental states of others (i.e., to mentalize). Parallel research has demonstrated that default network function declines over the lifespan, suggesting that older adults may show impairments in social-cognitive tasks that require mentalizing. Older and younger human adults were scanned using functional magnetic resonance imaging while performing three different social-cognitive tasks. Across three mentalizing paradigms, younger and older adults viewed animated shapes in brief social vignettes, stories about a person's moral actions, and false belief stories. Consistent with predictions, older adults responded less accurately to stories about others' false beliefs and made less use of actors' intentions to judge the moral permissibility of behavior. These impairments in performance during social-cognitive tasks were accompanied by age-related decreases across all three paradigms in the BOLD response of a single brain region, the dorsomedial prefrontal cortex. These findings suggest specific task-independent age-related deficits in mentalizing that are localizable to changes in circumscribed subregions of the default network.

Decoding the formation of reward predictions across learning.


Thorsten Kahnt, Jakob Heinzle, Soyoung Q Park, and John-Dylan Haynes
Journal of Neuroscience
2011 vol. 31 (41) pp. 14624-14630


学習(古典的条件付け)が進むにつれて、「期待報酬」と「実際に届いた報酬」のfMRI活動(眼窩前頭皮質、外背側前頭皮質、線条体)が徐々に似てくる。つまり、後者のfMRI活動を用いて訓練したサポート・ベクター・マシンが前者の活動をデコードできるようになる。

The predicted reward of different behavioral options plays an important role in guiding decisions. Previous research has identified reward predictions in prefrontal and striatal brain regions. Moreover, it has been shown that the neural representation of a predicted reward is similar to the neural representation of the actual reward outcome. However, it has remained unknown how these representations emerge over the course of learning and how they relate to decision making. Here, we sought to investigate learning of predicted reward representations using functional magnetic resonance imaging and multivariate pattern classification. Using a pavlovian conditioning procedure, human subjects learned multiple novel cue-outcome associations in each scanning run. We demonstrate that across learning activity patterns in the orbitofrontal cortex, the dorsolateral prefrontal cortex (DLPFC), and the dorsal striatum, coding the value of predicted rewards become similar to the patterns coding the value of actual reward outcomes. Furthermore, we provide evidence that predicted reward representations in the striatum precede those in prefrontal regions and that representations in the DLPFC are linked to subsequent value-based choices. Our results show that different brain regions represent outcome predictions by eliciting the neural representation of the actual outcome. Furthermore, they suggest that reward predictions in the DLPFC are directly related to value-based choices.

The neural code of reward anticipation in human orbitofrontal cortex.


Thorsten Kahnt, Jakob Heinzle, Soyoung Q Park, and John-Dylan Haynes
Proceedings of the National Academy of Sciences
2010 vol. 107 (13) pp. 6010-6015

「期待報酬」と「実際に届いた報酬」は眼窩前頭皮質に同じ様式で保持されている。前者(後者)のfMRI活動を用いて訓練したサポート・ベクター・マシンが後者(前者)の活動をデコードできる

An optimal choice among alternative behavioral options requires precise anticipatory representations of their possible outcomes. A fundamental question is how such anticipated outcomes are represented in the brain. Reward coding at the level of single cells in the orbitofrontal cortex (OFC) follows a more heterogeneous coding scheme than suggested by studies using functional MRI (fMRI) in humans. Using a combination of multivariate pattern classification and fMRI we show that the reward value of sensory cues can be decoded from distributed fMRI patterns in the OFC. This distributed representation is compatible with previous reports from animal electrophysiology that show that reward is encoded by different neural populations with opposing coding schemes. Importantly, the fMRI patterns representing specific values during anticipation are similar to those that emerge during the receipt of reward. Furthermore, we show that the degree of this coding similarity is related to subjects' ability to use value information to guide behavior. These findings narrow the gap between reward coding in humans and animals and corroborate the notion that value representations in OFC are independent of whether reward is anticipated or actually received.

2012年4月12日木曜日

Neural mechanisms of foraging


Nils Kolling, Timothy E J Behrens, Rogier B Mars, and Matthew F S Rushworth
Science 2012 vol. 336 (6077) pp. 95-98

Behavioral economic studies involving limited numbers of choices have provided key insights into neural decision-making mechanisms. By contrast, animals' foraging choices arise in the context of sequences of encounters with prey or food. On each encounter, the animal chooses whether to engage or, if the environment is sufficiently rich, to search elsewhere. The cost of foraging is also critical. We demonstrate that humans can alternate between two modes of choice, comparative decision-making and foraging, depending on distinct neural mechanisms in ventromedial prefrontal cortex (vmPFC) and anterior cingulate cortex (ACC) using distinct reference frames; in ACC, choice variables are represented in invariant reference to foraging or searching for alternatives. Whereas vmPFC encodes values of specific well-defined options, ACC encodes the average value of the foraging environment and cost of foraging.