Cutsuridis Vassilis, Jiang Shouyong, Dunn Matt J, Rosser Anne, Brawn James, Erichsen Jonathan T
School of Computer Science, University of Lincoln, Lincoln LN6 7TS, United Kingdom.
School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, United Kingdom.
Chaos. 2021 Jan;31(1):013121. doi: 10.1063/5.0021584.
Huntington's disease (HD), a genetically determined neurodegenerative disease, is positively correlated with eye movement abnormalities in decision making. The antisaccade conflict paradigm has been widely used to study response inhibition in eye movements, and reliable performance deficits in HD subjects have been observed, including a greater number and timing of direction errors. We recorded the error rates and response latencies of early HD patients and healthy age-matched controls performing the mirror antisaccade task. HD participants displayed slower and more variable antisaccade latencies and increased error rates relative to healthy controls. A competitive accumulator-to-threshold neural model was then employed to quantitatively simulate the controls' and patients' reaction latencies and error rates and uncover the mechanisms giving rise to the observed HD antisaccade deficits. Our simulations showed that (1) a more gradual and noisy rate of accumulation of evidence by HD patients is responsible for the observed prolonged and more variable antisaccade latencies in early HD; (2) the confidence level of early HD patients making a decision is unaffected by the disease; and (3) the antisaccade performance of healthy controls and early HD patients is the end product of a neural lateral competition (inhibition) between a correct and an erroneous decision process, and not the end product of a third top-down stop signal suppressing the erroneous decision process as many have speculated.
亨廷顿舞蹈症（HD）是一种由基因决定的神经退行性疾病，与决策过程中的眼球运动异常呈正相关。反扫视冲突范式已被广泛用于研究眼球运动中的反应抑制，并且在HD患者中观察到了可靠的行为表现缺陷，包括更多的方向错误数量和时机。我们记录了早期HD患者和年龄匹配的健康对照者执行镜像反扫视任务的错误率和反应潜伏期。与健康对照者相比，HD参与者的反扫视潜伏期更慢且更具变异性，错误率也更高。然后采用竞争性累加器至阈值神经模型来定量模拟对照者和患者的反应潜伏期和错误率，并揭示导致观察到的HD反扫视缺陷的机制。我们的模拟结果表明：（1）HD患者证据积累速度更缓慢且更具噪声，这导致了早期HD患者反扫视潜伏期延长且变异性更大；（2）早期HD患者做出决策的置信水平不受该疾病影响；（3）健康对照者和早期HD患者的反扫视表现是正确和错误决策过程之间神经侧向竞争（抑制）的最终结果，而不是如许多人推测的那样，是第三个自上而下的停止信号抑制错误决策过程的最终结果。
