一個(gè)國際小組最新研究發(fā)現(xiàn)，人們在深思熟慮或不假思索這兩種決策模式中的轉(zhuǎn)換能力,，取決于大腦中兩個(gè)區(qū)域的神經(jīng)連接強(qiáng)度,。
研究人員在美國《國家科學(xué)院學(xué)報(bào)》上報(bào)告說，在需要作出決定時(shí),，有人可以在不假思索和深思熟慮兩種決策模式中依據(jù)不同條件快速轉(zhuǎn)換,，而有的人卻總是感到左右為難?？茖W(xué)家們此前并不清楚究竟是什么原因造成這種個(gè)體差異,。
來自阿姆斯特丹大學(xué)的比特·福特斯曼和英國、德國及澳大利亞等國同行設(shè)計(jì)了兩個(gè)試驗(yàn),，分別要求受試者對(duì)一些簡單問題進(jìn)行判斷,。兩個(gè)試驗(yàn)中，前者要求力求準(zhǔn)確率而沒有時(shí)間限制,，后者則要求盡快做出決定不需考慮正確率,。
試驗(yàn)過程中對(duì)受試者大腦不同部位進(jìn)行掃描結(jié)果顯示，大腦皮層的某一特殊區(qū)域和大腦深處的另一特殊區(qū)域的神經(jīng)連接強(qiáng)度,，對(duì)受試者在兩種決策模式中切換的能力具有決定性影響,。研究人員打比方說，具有較強(qiáng)的連接強(qiáng)度好比是具有更多車道的高速公路,，更容易實(shí)現(xiàn)超車,，即思維模式的切換。
研究人員說：“這一研究結(jié)果顯示,，大腦內(nèi)部構(gòu)造的不同會(huì)對(duì)人們的決策能力造成影響,。”（生物谷Bioon.com）
Nature：酵母細(xì)胞交配前的決策
Nature：鴿子協(xié)調(diào)群體行為來自“民主”決策
羅中泉博士：決策過程的神經(jīng)網(wǎng)絡(luò)模型
生物谷推薦英文摘要：
PNAS doi: 10.1073/pnas.1004932107
Cortico-striatal connections predict control over speed and accuracy in perceptual decision making
Birte U. Forstmanna,1, Alfred Anwanderb, Andreas Sch?ferb, Jane Neumannb, Scott Brownc, Eric-Jan Wagenmakersa, Rafal Bogaczd, and Robert Turnerb
aDepartment of Psychology, University of Amsterdam, 1018 TV Amsterdam, The Netherlands;
bMax Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany;
cSchool of Psychology, University of Newcastle, 2308 Newcastle, Australia; and
dDepartment of Computer Science, University of Bristol, Bristol BS8 1UB, United Kingdom
When people make decisions they often face opposing demands for response speed and response accuracy, a process likely mediated by response thresholds. According to the striatal hypothesis, people decrease response thresholds by increasing activation from cortex to striatum, releasing the brain from inhibition. According to the STN hypothesis, people decrease response thresholds by decreasing activation from cortex to subthalamic nucleus (STN); a decrease in STN activity is likewise thought to release the brain from inhibition and result in responses that are fast but error-prone. To test these hypotheses—both of which may be true—we conducted two experiments on perceptual decision making in which we used cues to vary the demands for speed vs. accuracy. In both experiments, behavioral data and mathematical model analyses confirmed that instruction from the cue selectively affected the setting of response thresholds. In the first experiment we used ultra-high-resolution 7T structural MRI to locate the STN precisely. We then used 3T structural MRI and probabilistic tractography to quantify the connectivity between the relevant brain areas. The results showed that participants who flexibly change response thresholds (as quantified by the mathematical model) have strong structural connections between presupplementary motor area and striatum. This result was confirmed in an independent second experiment. In general, these findings show that individual differences in elementary cognitive tasks are partly driven by structural differences in brain connectivity. Specifically, these findings support a cortico-striatal control account of how the brain implements adaptive switches between cautious and risky behavior.
