预期情绪对跨期选择调控的认知神经机制

发布时间：2018-04-17 18:55

本文选题：跨期选择 + 延迟折扣　；参考：《西南大学》2014年硕士论文

【摘要】：跨期选择(intertemporal choice)是指个体对发生在不同时间的成本与收益进行权衡,进而做出的各种判断和选择(Loewenstein,1988; Frederick, Loewenstein,O'Donoghue,2002).亚当·斯密指出跨期选择不仅影响一个人的健康、财富与整体幸福感,也决定一个国家的经济繁荣的程度(Frederick, Loewenstein,O'Donoghue,2002)。因此,对跨期选择的认知与神经机制进行深入研究,既具有重要的科学价值,也能帮助个体、企业乃至政府做出更加科学、理性的决策。最近有研究发现,未来情境预期能够显著降低个体的延迟折扣率(Peters,Biichel,2010),做出对未来更加有利的决策(Benoit,et al.,2011)。然而,未来情境预期如何作用跨期选择的认知与神经机制并不清楚。为此,我们提出了一个“情境预期-情绪假设”(the emotion-of-episodic-prospection hypothesis)模型来解释其影响的认知与神经机制(LiuFeng,2013).因此,本研究利用行为实验和功能磁共振成像技术(fMRI),采用跨期选择任务范式,主要研究两个问题：(1)预期情绪对跨期选择调控的认知机制(研究一)；(2)预期情绪对跨期选择调控的神经基础与机制(研究二)。研究一分为三个实验,系统操纵预期想象的情绪效价(实验1-积极预期情绪；实验2-消极预期情绪；实验3-中性预期情绪),考察了预期情绪对跨期选择调控的认知机制。研究采用双曲线模型拟合延迟折扣率,在控制了被试即时情绪后,结果发现：(1)对未来积极事件的预期想象引发的积极情绪导致了延迟折扣率的降低(实验1)；(2)对未来消极事件的预期想象引发的消极情绪导致了延迟折扣率的增加(实验2)：(3)对未来中性事件的预期想象则没有改变个体的延迟折扣率(实验3)。这些结果支持了“情境预期-情绪假设”模型,预期想象本身不影响延迟折扣,而是通过预期情绪(不同效价)调节了延迟折扣变化的方向。研究二利用功能磁共振成像技术(fMRI),采用带预期想象标签(实验1-积极预期情绪；实验2-消极预期情绪；实验3-中性预期情绪)的跨期选择任务,考察预期情绪对跨期选择调控的神经基础与运行机制；重点探究预期情绪影响跨期选择的价值评估阶段还是选择阶段。行为结果进一步验证了研究一的结论：预期积极的情境事件能够降低个体的延迟折扣率,预期消极的情境事件会提高延迟折扣率,而预期中性的情境事件则不会改变延迟折扣率。磁共振结果表明：(1)预期想象积极事件,在评估阶段,“想象”与“不想象”对比,腹内侧前额叶(VMPFC)、前扣带(ACC)、后扣带(PCC)、脑岛(Insula)等脑区活性显著增强,也激活了海马(Hippocampus)、海马旁回(Parahippocampa Gyrus)等前瞻性记忆脑区；在选择阶段,“自主选择”与“跟随选择”相比,背侧扣带前回(dACC)、背外侧前额叶(DLPFC)、额下回(IFG)等脑区激活更强；海马旁回(Parahippocampa Gyrus)的激活程度能预测被试折扣率的变化程度(实验1)。(2)预期想象消极事件,在评估阶段,“想象”与“不想象”对比,腹内侧前额叶(VMPFC)、、脑岛(Insula)、扣带后回(PCc)等脑区活性显著增加；在选择阶段,同样“自主选择”与“跟随选择”相比,背侧扣带前回(dACC)、背外侧前额叶(DLPFC)等脑区活性更强；扣带后回(PCC)的激活程度能预测被试折扣率变化的程度(实验2)；(3)预期想象中性事件,在评估阶段,“想象”与“不想象”对比,无明显激活的脑区；在选择阶段,“自主选择”与“跟随选择”相比,额下回(IFG)等脑区活性更强。这些结果说明,预期情绪(或预期想象)可能通过对未来结果价值评估的影响,进而改变个体的选择偏好。综合而言,研究发现：(1)预期想象通过预期情绪调节了延迟折扣变化的方向：积极情绪预期会导致延迟折扣率的下降,消极的情绪预期则会导致延迟折扣率的上升,而中性情绪的预期想象则不会改变延迟折扣率。(2)预期想象通过影响被试对未来结果的价值评估来改变被试的选择偏好：预期积极事件会使个体赋予未来结果更大的价值,预期消极事件会使个体赋予未来结果更小的价值,而中性事件的预期并不会影响未来结果的价值评估。本研究较系统地探明了未来情境预期影响跨期选择的认知与神经机制,具有较高的科学价值；同时,也为延迟折扣的可塑性开辟了一条新的思路,对于改善和治疗特殊人群(如成瘾、暴饮暴食、病理性赌博)的跨期选择缺陷具有重要的实践意义。
[Abstract]:Intertemporal choice refers to the individual ' s trade - offs between costs and benefits that take place at different times , and the various judgments and choices ( Loewenstein , 1988 ; Frederick , Loewenstein , O ' Donghue , 2002 ) . Adam Smith points out that the cross - term choice not only affects one ' s health , wealth and overall well - being , but also determines the degree of economic prosperity of a country ( Frederick , Loewenstein , O ' Donghue , 2002 ) . Therefore , in - depth study on cognitive and neural mechanisms of cross - period selection has both important scientific value and more scientific and rational decision - making for individuals , enterprises and even government . Recently , it has been found that the future situation is expected to significantly reduce the individual ' s delay discount rate ( Peter , Biichel , 2010 ) and make more favorable decisions for the future ( Benoit , et al . , 2011 ) . However , it is not clear how the cognitive and neural mechanisms are expected to function in the future scenarios . To this end , we propose a " scenario - of - emotion hypothesis " model to explain the cognitive and neurological mechanism of its effects ( LiuFeng , 2013 ) . Therefore , this study uses behavioral experiment and functional magnetic resonance imaging technique to study two problems : ( 1 ) the cognitive mechanism of expected emotion to cross - stage selection and control ( research one ) ;
( 2 ) The neural basis and mechanism of expected emotion to regulate the cross - stage selection ( Study II ) .

The study was divided into three experiments , the system manipulated the expected perceived emotional potency ( experiment 1 - positive expected emotion ;
Lab 2 - Negative expected emotion ;
Experiment 3 - Neutral expected emotion ) , the cognitive mechanism of expected emotion to cross - stage selection control was investigated . The study used a hyperbolic model to fit the delay discount rate . After controlling the instant emotion , the results showed that : ( 1 ) the positive emotion caused by the expected imagination of positive events in the future led to a decrease in the delay discount rate ( experiment 1 ) ;
( 2 ) The expected imagination of the negative events in the future leads to an increase in the discount rate ( Experiment 2 ) : ( 3 ) The expected imagination of future neutral events does not alter the individual ' s delay discount rate ( Experiment 3 ) . These results support the context - expected - emotional hypothesis model , which is expected to do not affect the delayed discount itself , but rather adjusts the direction of the delayed discount change through the expected mood ( different potency ) .

To study the use of functional magnetic resonance imaging ( MRI ) , the expected imagination label was used ( experiment 1 - positive expected emotion ) ;
Lab 2 - Negative expected emotion ;
Experiment 3 - neutral expected emotion ) cross - stage selection task , investigating the expected emotion to the cross - stage selection and regulation of the neural basis and operation mechanism ;
The results of this study further validate the conclusion that positive contextual events can reduce the individual delay discount rate , expect negative contextual events to improve the discount rate , while the expected neutral contextual events will not change the discount rate .
In the selection phase , " autonomous selection " and " follow - up selection " , the brain areas such as the back - side buckle front - back ( dACC ) , the back - lateral frontal frontal lobe ( DLPFC ) , and the frontal - low - return - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - back - to - frontal gyrus are more active ;
( 2 ) Negative events are expected . In the assessment phase , " imagination " is compared with " imagining " , and the activity of brain regions such as the ventral medial frontal lobe ( VMPFC ) , the brain island ( PCc ) and the back ( PCc ) is significantly increased .
In the selection stage , the brain areas such as dACC , DLPFC , and DLPFC were also more active than " self - selection " and " follow - up selection " .
The degree of activation of the buckle back - back ( PCC ) can be predicted to the extent of the change in the discount rate ( Experiment 2 ) ;
( 3 ) It is expected to imagine the neutral event , in the assessment phase , " imagine " and " unimaginable " contrast , there is no obvious activation of the brain region ;
In the selection phase , " autonomous selection " is more active than " follow - up selection " . These results suggest that the expected mood ( or expected imagination ) may change the individual ' s preferences through the impact on the future outcome value assessment .

Overall , it is found that : ( 1 ) It is expected that the direction of delayed discount change is adjusted through expected mood : positive emotions are expected to lead to a drop in the discount rate , while negative emotions are expected to lead to an increase in the discount rate , while the expected imagination of the neutral mood will not change the discount rate .
At the same time , a new idea is opened for the plasticity of delayed discount , which is of great practical significance for improving and treating cross - stage selection defects of special populations ( such as addiction , binge eating , pathological gambling ) .

【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：B842

【参考文献】