最近一段時(shí)間，全球金融市場發(fā)生多年未遇的“動蕩”,，金融專家對其原因眾說紛紜,。值得一提的是，腦科專家也介入其中,，企圖叢神經(jīng)學(xué)的角度闡釋其原因,。
近日，美國和瑞士的科研人員宣布了一項(xiàng)探索人對風(fēng)險(xiǎn)的預(yù)測和反應(yīng)的神經(jīng)學(xué)新發(fā)現(xiàn),。這項(xiàng)得到美國和瑞士兩國國家科學(xué)基金支持的研究發(fā)現(xiàn),，在很大程度上，人腦和電腦對風(fēng)險(xiǎn)計(jì)算的差別可能是近期市場風(fēng)波背后的罪魁禍?zhǔn)?，這樣的風(fēng)波每隔10到20年就會出現(xiàn)一次,，讓金融市場和股民備受折磨,。
研究人員還表示，這項(xiàng)發(fā)表在《神經(jīng)科學(xué)雜志》(Journal of Neuroscience)上的研究成果將最終幫助金融界開發(fā)更可靠的市場活動預(yù)測模型,。
項(xiàng)目負(fù)責(zé)人,、洛桑聯(lián)邦理工學(xué)院(Federal Institute of Technology in Lausanne)教授Peter Bossaerts介紹，人腦與金融市場對風(fēng)險(xiǎn)的計(jì)算存在很大差異,。Bossaerts和他的同事深入研究了情緒因素在此過程中所起的作用,。
研究發(fā)現(xiàn)，人腦在計(jì)算風(fēng)險(xiǎn)時(shí)不僅考慮過去的判斷失誤,，它的內(nèi)在算式還對許多財(cái)務(wù)模型不能預(yù)測的稀有事項(xiàng)更敏感,。研究人員還注意到人的情緒在精細(xì)設(shè)計(jì)的財(cái)務(wù)模型出錯時(shí)所起的作用。
Bossaerts表示：“如果建有合適的模型,，被金融領(lǐng)域某些人標(biāo)為‘無法預(yù)測’的事件都會在可控范圍內(nèi),。目前的次貸危機(jī)，實(shí)際上也是可以預(yù)測的,。但通常的情況是：一旦市場出現(xiàn)狀況,，人們就關(guān)掉電腦，把這些模型扔出窗外,。”
Bossaerts指出,，問題的癥結(jié)在于發(fā)現(xiàn)人腦用于評估風(fēng)險(xiǎn)的算法?？蒲腥藛T將能以此為基礎(chǔ)對現(xiàn)有工具進(jìn)行改造,，來彌補(bǔ)缺陷。
研究人腦對風(fēng)險(xiǎn)的處理方法并不復(fù)雜,，近10年,，英、美和日本領(lǐng)尖學(xué)府中像Bossaerts這樣的科研人員已在神經(jīng)科學(xué),、風(fēng)險(xiǎn)和金融市場之間建立了重要的跨學(xué)科橋梁,。經(jīng)過5年研究，Bossaerts等人在構(gòu)建對情緒來源的研究時(shí)發(fā)現(xiàn),，人對風(fēng)險(xiǎn)的反應(yīng)在很大程度上由島葉皮質(zhì)(insula cortex)的活動決定,，而過去很少有針對該領(lǐng)域的研究。
引起科學(xué)家們特殊興趣的是島葉皮質(zhì)前端的初期活化作用,，他們通過利用功能映射,，發(fā)現(xiàn)了大腦中被稱為前扣帶皮質(zhì)(anterior cortex)的這一部分。
研究人員相信,，就像在世界主要證券交易所不斷上演的那種類似幸福感的情緒是與風(fēng)險(xiǎn)的不合理評估相連一樣,，那些預(yù)測情況的風(fēng)險(xiǎn)性比實(shí)際要大的人則會對焦慮等情緒更加敏感。
Bossaerts所在的不確定情況下決策實(shí)驗(yàn)室(Laboratory for Decision Making under Uncertainty)發(fā)表的一項(xiàng)聲明稱，在此以前,，對島葉皮質(zhì)如何影響錯誤決策的研究是一項(xiàng)空白,。他指出，在認(rèn)識個體對待風(fēng)險(xiǎn)的方式時(shí),，科學(xué)家和金融界專業(yè)人士將能對人腦無法自主完成的部分加以補(bǔ)充,。
Bossaerts解釋說：“并補(bǔ)充說盡管‘精細(xì)設(shè)計(jì)’的財(cái)務(wù)模型可能很好，它們卻不能給出沒有風(fēng)險(xiǎn)的預(yù)測,。”在Bossaerts看來,，傳統(tǒng)模型失誤系數(shù)有可能非常大，他提醒那些自稱為人才的金融界人士,，在計(jì)算時(shí)要多復(fù)查一遍,。（生物谷Bioon.com）
生物谷推薦原始出處：
Journal of Neuroscience，2008, 28(11):2745-2752,，Kerstin Preuschoff, Steven R. Quartz, and Peter Bossaerts
Human Insula Activation Reflects Risk Prediction Errors As Well As Risk
Kerstin Preuschoff,1,4 Steven R. Quartz,1,2 and Peter Bossaerts1,2,3
1Computation and Neural Systems Program and 2Division of Humanities and Social Sciences, Caltech, Pasadena, California 91125, 3Ecole Polytechnique Fédérale Lausanne, CH-1015 Lausanne, Switzerland, and 4Institute for Empirical Research in Economics, University of Zurich, CH-8006 Zurich, Switzerland
Understanding how organisms deal with probabilistic stimulus-reward associations has been advanced by a convergence between reinforcement learning models and primate physiology, which demonstrated that the brain encodes a reward prediction error signal. However, organisms must also predict the level of risk associated with reward forecasts, monitor the errors in those risk predictions, and update these in light of new information. Risk prediction serves a dual purpose: (1) to guide choice in risk-sensitive organisms and (2) to modulate learning of uncertain rewards. To date, it is not known whether or how the brain accomplishes risk prediction. Using functional imaging during a simple gambling task in which we constantly changed risk, we show that an early-onset activation in the human insula correlates significantly with risk prediction error and that its time course is consistent with a role in rapid updating. Additionally, we show that activation previously associated with general uncertainty emerges with a delay consistent with a role in risk prediction. The activations correlating with risk prediction and risk prediction errors are the analogy for risk of activations correlating with reward prediction and reward prediction errors for reward expectation. As such, our findings indicate that our understanding of the neural basis of reward anticipation under uncertainty needs to be expanded to include risk prediction.
