Howsley Philippa, Levita Liat
Department of Psychology, The University of Sheffield, Sheffield, South Yorkshire, S1 2LT, United Kingdom.
Dev Cogn Neurosci. 2017 Jun;25:246-259. doi: 10.1016/j.dcn.2017.03.001. Epub 2017 Mar 12.
This study examined whether changes in perceptual processes can partially account for the increase in reward-orientated behaviour during adolescence. This was investigated by examining reinforcement-dependent potentiation to discriminative stimuli (S) that predicted rewarding or threatening outcomes. To that end, perceptual event-related potentials that are modulated by motivationally salient stimuli, the N170 and Late Positive Potential (LPP), were recorded from 30 preadolescents (9-12 years), 30 adolescents (13-17 years), and 34 late adolescents (18-23 years) while they completed an instrumental task in which they emitted or omitted a motor response to obtain rewards and avoid losses. The LPP, but not the N170, showed age, but not gender, differences in reinforcement-dependent potentiation; preadolescents, adolescents, and late adolescents showed potentiation to S that predicted a threat, whereas only preadolescents showed potentiation to S that predicted a reward. Notably, the magnitude of threat-related LPP reinforcement-dependent potentiation decreased during the course of adolescence. In addition, greater sensation seeking was associated with greater LPP amplitudes in preadolescent males, but smaller LPP amplitudes in late adolescent males. Critically, these findings provide initial evidence for developmental differences in value-related coding in perceptual areas, where adolescents show greater perceptual biases to avoidance-related cues than to reward-related cues.
本研究考察了知觉过程的变化是否能部分解释青春期奖励导向行为的增加。通过检测对预测奖励或威胁结果的辨别性刺激(S)的强化依赖增强来进行调查。为此,在30名青春期前儿童(9 - 12岁)、30名青少年(13 - 17岁)和34名青年晚期(18 - 23岁)完成一项工具性任务时,记录了由动机显著刺激调制的知觉事件相关电位,即N170和晚期正电位(LPP)。在该任务中,他们发出或不发出运动反应以获得奖励并避免损失。LPP而非N170在强化依赖增强方面表现出年龄差异而非性别差异;青春期前儿童、青少年和青年晚期对预测威胁的S表现出增强,而只有青春期前儿童对预测奖励的S表现出增强。值得注意的是,与威胁相关的LPP强化依赖增强的幅度在青春期过程中降低。此外,在青春期前男性中,更高的感觉寻求与更大的LPP波幅相关,但在青年晚期男性中则与更小的LPP波幅相关。至关重要的是,这些发现为知觉区域中与价值相关编码的发育差异提供了初步证据,即青少年对与回避相关线索的知觉偏差大于对与奖励相关线索的知觉偏差。