Developmental Cognitive Neuroscience (DCN) Laboratory, School of Psychology, University of Central Lancashire, UK; Developmental Brain-Behaviour Laboratory, Psychology, University of Southampton, UK; Division of Neuroscience & Experimental Psychology, University of Manchester, UK.
Department of Cognitive Science, Macquarie University, Australia.
Neuroimage Clin. 2019;23:101917. doi: 10.1016/j.nicl.2019.101917. Epub 2019 Jul 2.
The delay aversion hypothesis argues that the tendency for impulsive choice (preference for smaller sooner over larger later rewards) is motivated by the escape of negative affective states associated with delay. This model predicts that individuals with ADHD find the imposition of delay before an outcome or event especially aversive and its escape reinforcing. Consistent with this, fMRI studies show that ADHD is associated with amygdala hyper-sensitivity to cues of delay. However, evidence that delay escape is reinforcing is lacking. Here we extend fMRI research by using electrophysiological methods to study the reinforcing properties of delay-escape in ADHD. Thirty controls and 25 adolescents with ADHD aged 10-15 years performed the Escape Delay Incentive (EDI) task- in which pre-target cues indicated three conditions: i) CERTAIN DELAY: delay would follow a response irrespective of response speed ii) CONDITIONAL DELAY: delay would only follow if the response was too slow and iii) NO DELAY: delay would follow the response whatever the speed. We focused on the Contingent Negative Variation (CNV), a cue-evoked marker of motivated response preparation, across two time windows (CNV1 and CNV2). We took measures of parent, teacher and self-rated ADHD symptoms, task performance (RT) and self-rated delay aversion. We isolated CNV components and compared these between ADHD and controls. Adolescents with ADHD displayed a larger CNV2 to the CONDITIONAL DELAY than the CERTAIN DELAY cues compared to controls. However, this effect was not mirrored at the performance level and was unrelated to self-reported delay aversion. Our study provides the first ERP evidence that delay escape differentially reinforcers neural activation of attention preparation in ADHD cases. Future studies should examine the impact of varying cognitive load on task EDI performance.
延迟回避假说认为，冲动选择（偏好较小的即时奖励而不是较大的延迟奖励）的倾向是由与延迟相关的负面情感状态的逃避所驱动的。该模型预测，ADHD 个体发现，在获得结果或事件之前，延迟的施加尤其令人厌恶，而延迟的逃避则具有强化作用。这与 fMRI 研究一致，这些研究表明，ADHD 与杏仁核对延迟线索的超敏反应有关。然而，缺乏延迟逃避具有强化作用的证据。在这里，我们通过使用电生理方法来扩展 fMRI 研究，以研究 ADHD 中延迟逃避的强化特性。30 名对照者和 25 名年龄在 10-15 岁的 ADHD 青少年参与者完成了逃避延迟激励（EDI）任务——在该任务中，预目标线索指示了三种条件：i）确定延迟：无论反应速度如何，延迟都会紧随其后；ii）条件延迟：只有当反应太慢时，延迟才会出现；iii）无延迟：无论反应速度如何，延迟都会紧随其后。我们重点关注了条件性负变（CNV），这是一种对动机反应准备的线索诱发标记，跨越两个时间窗口（CNV1 和 CNV2）。我们对父母、教师和自我报告的 ADHD 症状、任务表现（RT）和自我报告的延迟回避进行了测量。我们分离了 CNV 成分，并将其与 ADHD 和对照组进行了比较。与对照组相比，ADHD 青少年对条件性延迟的 CNV2 比确定性延迟的 CNV2 更大。然而，这种效应在表现水平上并没有得到反映，与自我报告的延迟回避无关。我们的研究提供了第一个 ERP 证据，表明延迟逃避会对 ADHD 病例中注意力准备的神经激活产生不同的强化作用。未来的研究应该检查不同认知负荷对任务 EDI 表现的影响。
