The Neuropsychological Laboratory, CNS-Fed, Paris, France.
Clin Neurophysiol. 2022 Aug;140:145-158. doi: 10.1016/j.clinph.2022.06.003. Epub 2022 Jun 18.
People with attention deficit and hyperactivity disorder (ADHD) present attentional and emotional deficits and show paradoxical qualities such as hyperfocus. Previous studies have reported errors, slowness, and reaction time (RT) variability using eye movements. This study aimed to explore the underlying mechanisms of ADHD further.
Thirty French children and teenagers, 15 with ADHD and 15 neurotypical (NT), underwent a saccadic eye movement task. We conducted conventional analysis (movement duration, precision, velocity, RT) and Bayesian analysis.
Saccade duration and velocity failed to differentiate the two groups, whereas amplitude was higher in ADHD than in NT participants. Saccade RT and variability were higher in ADHD than in NT participants. In the Bayesian analysis, ADHD altered the main distribution of saccades and of early saccades but did not influence the express saccade triggering.
ADHD disrupts two mechanisms of action: it reduces the gain of the decision signal, thus explaining slowness and variability; it quickens the decision process of early responses at the origin of short-latency but controlled movements.
These premises and their interconnections explain previous observations and support the striatal-frontal wiring of ADHD, thus explaining ADHD complexity in its negative and positive manifestations.
患有注意力缺陷多动障碍（ADHD）的人表现出注意力和情绪缺陷，并表现出专注等矛盾的特质。先前的研究已经使用眼动报告了错误、缓慢和反应时间（RT）的可变性。本研究旨在进一步探讨 ADHD 的潜在机制。
30 名法国儿童和青少年，15 名 ADHD 患者和 15 名神经典型（NT）患者接受了眼跳眼动任务。我们进行了常规分析（运动持续时间、精度、速度、RT）和贝叶斯分析。
扫视持续时间和速度未能区分两组，而 ADHD 组的幅度高于 NT 组。ADHD 组的 RT 和变异性高于 NT 组。在贝叶斯分析中，ADHD 改变了扫视和早期扫视的主要分布，但不影响快速扫视的触发。
ADHD 扰乱了两种作用机制：它降低了决策信号的增益，从而解释了缓慢和变异性；它加速了早期反应的决策过程，导致潜伏期短但控制运动。
这些前提及其相互关系解释了先前的观察结果，并支持 ADHD 的纹状体-额叶连接，从而解释了 ADHD 在其阴性和阳性表现中的复杂性。
