4月6日,，國(guó)際著名雜志Science在線刊登了國(guó)外研究人員的最新研究成果“Neural Mechanisms of Foraging”,，文章中,，研究人員發(fā)現(xiàn)了支持覓食行為的一種大腦活動(dòng)形式。
覓食中的動(dòng)物必須決定是在遇到食物時(shí)就選擇該食物選項(xiàng),，還是繼續(xù)尋找以期更好的食物會(huì)出現(xiàn),。這與在所有選項(xiàng)同時(shí)存在時(shí)從中進(jìn)行挑選不同，而這卻是在大多數(shù)有關(guān)人類決策的研究中要求受試者去做的,。
Nils Kolling及其在英國(guó)的同事們?cè)O(shè)計(jì)了一項(xiàng)實(shí)驗(yàn),，在該實(shí)驗(yàn)中，人類志愿者在作出覓食類型的決定的同時(shí)他們的大腦活動(dòng)也受到監(jiān)測(cè),。他們發(fā)現(xiàn),，一個(gè)叫做背側(cè)前扣帶回皮層的區(qū)域會(huì)提供持續(xù)性的環(huán)境豐富信號(hào)——換言之，它會(huì)追蹤“林中有什么”與“手中有什么”的相對(duì)價(jià)值,。這種類型的腦信號(hào)是由覓食理論所預(yù)計(jì)的,，但不是由神經(jīng)經(jīng)濟(jì)學(xué)或反應(yīng)沖突理論所預(yù)計(jì)的。研究人員還分析了另一區(qū)域——即腹內(nèi)側(cè)前額葉皮層的腦活動(dòng),，人們認(rèn)為該區(qū)域也促成了決策過(guò)程,。他們發(fā)現(xiàn)，這一區(qū)域缺乏任何與覓食有關(guān)的信號(hào),，相反其反映的是個(gè)體的定義明確的選擇價(jià)值,。（生物谷Bioon.com）
doi:10.1126/science.1216930
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Neural Mechanisms of Foraging
Nils Kolling1,*, Timothy E. J. Behrens1,2, Rogier B. Mars1,2, Matthew F. S. Rushworth1,2
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.
