Center for Applied Brain and Cognitive Sciences, Medford, MA, United States; U.S. Army Natick Soldier Research, Development, and Engineering Center, Natick, MA, United States; Tufts University, Department of Psychology, Medford, MA, United States.
Center for Applied Brain and Cognitive Sciences, Medford, MA, United States; U.S. Army Natick Soldier Research, Development, and Engineering Center, Natick, MA, United States.
Int J Psychophysiol. 2017 Oct;120:60-68. doi: 10.1016/j.ijpsycho.2017.07.008. Epub 2017 Jul 18.
Perceptual decision making involves gathering and interpreting sensory information to effectively categorize the world and inform behavior. For instance, a radiologist distinguishing the presence versus absence of a tumor, or a luggage screener categorizing objects as threatening or non-threatening. In many cases, sensory information is not sufficient to reliably disambiguate the nature of a stimulus, and resulting decisions are done under conditions of uncertainty. The present study asked whether several oculomotor metrics might prove sensitive to transient states of uncertainty during perceptual decision making. Participants viewed images with varying visual clarity and were asked to categorize them as faces or houses, and rate the certainty of their decisions, while we used eye tracking to monitor fixations, saccades, blinks, and pupil diameter. Results demonstrated that decision certainty influenced several oculomotor variables, including fixation frequency and duration, the frequency, peak velocity, and amplitude of saccades, and phasic pupil diameter. Whereas most measures tended to change linearly along with decision certainty, pupil diameter revealed more nuanced and dynamic information about the time course of perceptual decision making. Together, results demonstrate robust alterations in eye movement behavior as a function of decision certainty and attention demands, and suggest that monitoring oculomotor variables during applied task performance may prove valuable for identifying and remediating transient states of uncertainty.
知觉决策涉及收集和解释感官信息，以有效地对世界进行分类并指导行为。例如，放射科医生区分肿瘤的存在与否，或行李安检员将物体分类为威胁或非威胁。在许多情况下，感官信息不足以可靠地区分刺激的性质，因此决策是在不确定的条件下做出的。本研究探讨了几种眼动指标是否可以敏感地反映知觉决策过程中的短暂不确定性状态。参与者观看了清晰度不同的图像，并被要求将其分类为面部或房屋，并对其决策的确定性进行评分，同时我们使用眼动追踪监测注视、扫视、眨眼和瞳孔直径。结果表明，决策的确定性会影响几种眼动变量，包括注视的频率和持续时间、扫视的频率、峰值速度和幅度，以及瞳孔的相位直径。虽然大多数指标往往随着决策的确定性呈线性变化，但瞳孔直径揭示了关于知觉决策过程时间进程的更细微和动态的信息。总之，研究结果表明，眼动行为会随着决策的确定性和注意力需求而发生显著变化，这表明在应用任务执行期间监测眼动变量可能有助于识别和纠正短暂的不确定性状态。
