Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet and Stockholm Health Care Services, Region Stockholm, Gävlegatan 22, 113 30, Stockholm, Sweden.
Uppsala Child and Baby Lab, Department of Psychology, Uppsala University, Box 1225, 751 42, Uppsala, Sweden.
Eur Child Adolesc Psychiatry. 2020 Dec;29(12):1635-1644. doi: 10.1007/s00787-020-01484-w. Epub 2020 Feb 1.
Attenuated baseline arousal has been hypothesized to underlie symptoms of attention deficit/hyperactivity disorder (ADHD). A behavioral signature of reduced baseline arousal is an increased beneficiary effect of warning signals in reaction tasks. This paradoxical effect is believed to be caused by a temporary increase in arousal induced by warning signals. In a preregistered study, we tested the hypothesis that children with high levels of ADHD symptoms would be hyperresponsive to warning signals in a well-established visual attention task (the gap/overlap paradigm). Previous studies using this task have found slower and more variable saccadic reaction times in children with ADHD compared to typically developing children, suggesting that these eye movement metrics are candidate biomarkers. We examined 71 children, of which 1/3 had a diagnosis of ADHD, using both dimensional analyses and group comparisons. Previously reported findings of reduced saccadic latency and increased latency variability were replicated. Importantly, saccadic latency was normalized by auditory warning signals. Analyses of pupil dilation, a physiological index of arousal and locus coeruleus-noradrenergic activity, confirmed that warning signals led to enhanced arousal. Our findings are novel and contribute to our understanding of arousal and attention in ADHD and have implications for treatment and interventions.
研究假设，注意力缺陷多动障碍（ADHD）的症状与基线警觉降低有关。基线警觉降低的行为特征是，在反应任务中，警告信号的受益效应增加。这种自相矛盾的效应被认为是由警告信号引起的警觉暂时增加所致。在一项预先注册的研究中，我们测试了以下假设：在一项成熟的视觉注意任务（缺口/重叠范式）中，具有高水平 ADHD 症状的儿童对警告信号的反应会更加敏感。使用该任务的先前研究发现，与正常发育的儿童相比，ADHD 儿童的眼跳反应时更慢且更可变，这表明这些眼动指标是候选生物标志物。我们使用维度分析和组间比较检查了 71 名儿童，其中 1/3 被诊断为 ADHD。先前报道的眼跳潜伏期缩短和潜伏期变异性增加的发现得到了重复。重要的是，听觉警告信号使眼跳潜伏期正常化。瞳孔扩张分析，即警觉和蓝斑-去甲肾上腺素能活动的生理指标，证实警告信号会导致警觉增强。我们的研究结果是新颖的，有助于我们理解 ADHD 中的警觉和注意力，并对治疗和干预具有启示意义。
