Psychophysiology Laboratory, Department of Humanities and Social Sciences, Indian Institute of Technology Bombay, Mumbai, 400076, India.
Sci Rep. 2021 Nov 15;11(1):22277. doi: 10.1038/s41598-021-01579-7.
Decision makers tend to give magnified significance to immediately available rewards which leads to intertemporal preference reversals, which is a form of self-control failure. The objective of the present study was to understand the cognitive and neural underpinnings of this phenomenon using event-related potentials (ERP) and their source localization using standardized low-resolution brain electromagnetic tomography analysis (sLORETA). Twenty-four participants performed a money choice task, where they made choices between a smaller-sooner and a larger-later reward, which included trials with and without an immediately available option, while their electroencephalography (EEG) activity was recorded. Trials with and without immediacy were identical except that the latter involved a front-end delay added to both the rewards. Results showed that presence of immediacy made the choices significantly more impulsive. Presence of immediate reward elicited larger visual P2 and late positive potential (LPP), indicating enhanced capture of automatic and sustained attention respectively, and smaller N2, indicative of diminished engagement of cognitive control processes. Source localization revealed increased activity in the visual cortex in the presence of immediacy, signifying higher valuation. Higher activation of areas of insula during P2-suggesting increased awareness of visceral signals-predicted larger impulsive preference reversals. The results suggest that presence of immediate reward biases the choice very early during the decision making process by precipitating visceral states that triggers approach behaviour, and highlight the need to adopt strategies like precommitment to counter the effect.
决策者往往会夸大即时可得奖励的重要性,从而导致跨期偏好反转,这是一种自我控制失败的形式。本研究的目的是使用事件相关电位(ERP)及其源定位(使用标准化低分辨率脑电磁层析成像分析(sLORETA))来理解这种现象的认知和神经基础。二十四名参与者进行了一项货币选择任务,在该任务中,他们在较小的即时奖励和较大的延迟奖励之间做出选择,其中包括有和没有即时奖励的试验,同时记录他们的脑电图(EEG)活动。有和没有即时性的试验是相同的,只是后者在两个奖励中都增加了前端延迟。结果表明,即时性的存在使选择更加冲动。即时奖励的存在引发了更大的视觉 P2 和晚期正电位(LPP),分别表示自动和持续注意力的增强捕捉,以及更小的 N2,表示认知控制过程的参与减少。源定位显示,在即时性存在的情况下,视觉皮层的活动增加,表明估值更高。P2 期间岛叶的更高激活-表明内脏信号的意识增加-预测更大的冲动偏好反转。结果表明,即时奖励的存在通过引发触发接近行为的内脏状态,在决策过程的早期就使选择产生偏见,并强调需要采取预先承诺等策略来对抗这种影响。