Data from: Pupil diameter tracks lapses of attention

Our ability to sustain attention for prolonged periods of time is limited. Studies on the relationship between lapses of attention and psychophysiological markers of attentional state, such as pupil diameter, have yielded contradicting results. Here, we investigated the relationship between tonic fluctuations in pupil diameter and performance on a demanding sustained attention task. We found robust linear relationships between baseline pupil diameter and several measures of task performance, suggesting that attentional lapses tended to occur when pupil diameter was small. However, these observations were primarily driven by the joint effects of time-on-task on baseline pupil diameter and task performance. The linear relationships disappeared when we statistically controlled for time-on-task effects and were replaced by consistent inverted U-shaped relationships between baseline pupil diameter and each of the task performance measures, such that most false alarms and the longest and most variable response times occurred when pupil diameter was both relatively small and large. Finally, we observed strong linear relationships between the temporal derivative of pupil diameter and task performance measures, which were largely independent of time-on-task. Our results help to reconcile contradicting findings in the literature on pupil-linked changes in attentional state, and are consistent with the adaptive gain theory of locus coeruleus-norepinephrine function. Moreover, they suggest that the derivative of baseline pupil diameter is a potentially useful psychophysiological marker that could be used in the on-line prediction and prevention of attentional lapses.人类长时间维持注意力的能力存在固有局限。针对注意力瞬断（attentional lapses）与注意力状态的心理生理标记物（如瞳孔直径（pupil diameter））之间关联的现有研究，所得结论始终相互矛盾。本研究探究了基线瞳孔直径（baseline pupil diameter）的紧张性波动与高负荷持续性注意力任务作业表现之间的关联。结果显示，基线瞳孔直径与多项任务绩效指标间存在稳健的线性相关，提示注意力瞬断多发生于瞳孔直径偏小之时。然而，该关联主要由任务执行时长（time-on-task）对基线瞳孔直径与任务绩效的联合影响所驱动：在统计学上控制任务执行时长的效应后，原线性相关消失，取而代之的是基线瞳孔直径与各项任务绩效指标间稳定的倒U型关联——即当瞳孔直径既相对偏小又相对偏大时，虚报（false alarms）次数最多，反应时（response times）最长且变异性最强。此外，我们还观察到瞳孔直径的时间导数（temporal derivative）与任务绩效指标间存在强线性相关，且该相关基本不受任务执行时长的影响。本研究结果有助于调和既往关于瞳孔相关注意力状态变化的矛盾研究结论，且与蓝斑-去甲肾上腺素（locus coeruleus-norepinephrine）系统的适应性增益理论（adaptive gain theory）相符。进一步而言，研究结果表明，基线瞳孔直径的时间导数是一项极具应用潜力的心理生理标记物，可用于在线预测与预防注意力瞬断。