Dopamine signals for reward value and risk: basic and recent data.
Dopamine signals for reward value and risk: basic and recent data.
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DOI：
10.1186/1744-9081-6-24
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发表时间：
2010-04-23
期刊：
影响因子：
--
通讯作者：
Schultz W
中科院分区：
文献类型：
--
作者：
Schultz W
之前的损伤、电自我刺激和药物成瘾研究表明，中脑多巴胺系统是大脑奖励系统的一部分。本文对多巴胺神经元对环境刺激的基本信号进行了最新综述。所描述的实验使用标准的行为和神经生理学方法来记录清醒猴子在特定行为任务中的单个多巴胺神经元的活动。多巴胺神经元对外界刺激表现出阶段性激活。该信号反映奖赏、身体突显、风险和惩罚，按反应神经元部分的降序排列。期望报酬价值是经济选择的关键决策变量。奖励响应编码奖励值、概率及其乘积和期望值。神经元对奖励值进行编码，因为奖励值与预测值不同，从而满足了学习理论对双向预测误差教学信号的基本要求。此响应以标准差为单位进行缩放。相比之下，相对较少的多巴胺神经元在惩罚性刺激和条件性厌恶刺激后显示出相态激活，这表明奖赏反应与一般的注意和唤醒缺乏联系。很大比例的多巴胺神经元也会被强烈的、身体上突出的刺激激活。当刺激是新的时，这种反应会增强；它似乎与奖励价值信号不同。多巴胺神经元也表现出对非奖赏刺激的非特异性激活，这可能是由于相似刺激的泛化和初级奖赏的假条件反射。这些激活比奖赏反应更短，而且通常紧随其后的是活动抑制。另一个重要的决策变量是另一个独立的、较慢的多巴胺信号，它告诉人们风险。预测误差响应仅与报酬有关；它由预测报酬的风险来衡量。神经生理学研究揭示了多巴胺信号的相位性，它传递的信息主要与奖赏有关，但不完全与奖励有关。尽管多巴胺信号并不是完全同质的，但在大多数其他涉及目标定向行为的大脑结构中，多巴胺信号比神经元活动更受限制和刻板印象。
Previous lesion, electrical self-stimulation and drug addiction studies suggest that the midbrain dopamine systems are parts of the reward system of the brain. This review provides an updated overview about the basic signals of dopamine neurons to environmental stimuli. The described experiments used standard behavioral and neurophysiological methods to record the activity of single dopamine neurons in awake monkeys during specific behavioral tasks. Dopamine neurons show phasic activations to external stimuli. The signal reflects reward, physical salience, risk and punishment, in descending order of fractions of responding neurons. Expected reward value is a key decision variable for economic choices. The reward response codes reward value, probability and their summed product, expected value. The neurons code reward value as it differs from prediction, thus fulfilling the basic requirement for a bidirectional prediction error teaching signal postulated by learning theory. This response is scaled in units of standard deviation. By contrast, relatively few dopamine neurons show the phasic activation following punishers and conditioned aversive stimuli, suggesting a lack of relationship of the reward response to general attention and arousal. Large proportions of dopamine neurons are also activated by intense, physically salient stimuli. This response is enhanced when the stimuli are novel; it appears to be distinct from the reward value signal. Dopamine neurons show also unspecific activations to non-rewarding stimuli that are possibly due to generalization by similar stimuli and pseudoconditioning by primary rewards. These activations are shorter than reward responses and are often followed by depression of activity. A separate, slower dopamine signal informs about risk, another important decision variable. The prediction error response occurs only with reward; it is scaled by the risk of predicted reward. Neurophysiological studies reveal phasic dopamine signals that transmit information related predominantly but not exclusively to reward. Although not being entirely homogeneous, the dopamine signal is more restricted and stereotyped than neuronal activity in most other brain structures involved in goal directed behavior.
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影响因子：
56.9
作者：
Fiorillo, CD;Tobler, PN;Schultz, W
通讯作者：
Schultz, W
影响因子：
2.5
作者：
Bayer, Hannah M.;Lau, Brian;Glimcher, Paul W.
通讯作者：
Glimcher, Paul W.
影响因子：
6.1
作者：
Bernoulli, Daniel
通讯作者：
Bernoulli, Daniel
影响因子：
2.5
作者：
LJUNGBERG, T;APICELLA, P;SCHULTZ, W
通讯作者：
SCHULTZ, W
影响因子：
5.4
作者：
MACKINTOSH, NJ
通讯作者：
MACKINTOSH, NJ