美國(guó)研究人員16日說，大腦中一些基因會(huì)影響人們的策略性行為，包括賭博、投資等。
加州大學(xué)伯克利分校和伊利諾伊大學(xué)厄巴納-尚佩恩分校研究人員在美國(guó)《國(guó)家科學(xué)院學(xué)報(bào)》上報(bào)告說，這些基因通過大腦中的神經(jīng)遞質(zhì)多巴胺發(fā)揮作用。多巴胺是大腦獎(jiǎng)賞系統(tǒng)的關(guān)鍵組成部分，與人的快感有關(guān)，而他們的研究則首次把人們的策略性行為與多巴胺調(diào)控基因聯(lián)系起來。研究人員在新加坡招募了217名大學(xué)生，從其基因組中找到約70萬個(gè)基因突變，新研究主要針對(duì)其中12個(gè)多巴胺調(diào)控基因的143個(gè)突變。然后，這些受試者被安排通過電腦與一名匿名對(duì)手進(jìn)行賭博，研究人員在一旁利用磁共振成像技術(shù)監(jiān)控他們的大腦活動(dòng)。
研究表明，那些能更好地判斷對(duì)手想法并予以回應(yīng)的人，他們大腦內(nèi)側(cè)前額葉皮層中的3個(gè)多巴胺調(diào)控基因出現(xiàn)突變；那些在失敗后能更好地改變應(yīng)對(duì)策略的人，他們大腦紋狀體的2個(gè)多巴胺調(diào)控基因出現(xiàn)突變。
這項(xiàng)研究把賭博、投資等策略性決定與一系列基因聯(lián)系在一起。研究人員下一步計(jì)劃在老年人群中展開研究，分析事業(yè)成就與基因等因素之間是否存在關(guān)聯(lián)。
Neural representation of expected value in the adolescent brain
Previous work shows that the adolescent reward system is hyperactive, but this finding may be confounded by differences in how teens value money. To address this, we examined the neural ontogeny of objective value representation. Adolescent and adult participants performed a monetary gambling task in which they chose to accept or reject gambles of varying expected value. Increasing expected value had a stronger influence over gambling choices in adolescents relative to adults, an effect that was paralleled by greater activation in the ventral striatum in adolescents. This unique adolescent ventral striatum response remained even after matching groups on acceptance behavior. These behavioral and neural data suggest that the value of available options has a greater influence in adolescent versus adult choices, even when objective value and subjective choice are held constant. This research provides further evidence that hyperactivation of reward circuitry in adolescence may be a normative ontogenetic shift that is due to greater valuation in the adolescent brain.
