Department of Psychology, New York University, New York, NY, USA.
Department of Psychology, University of Texas in Austin, Austin, TX, USA.
J Vis. 2023 May 2;23(5):6. doi: 10.1167/jov.23.5.6.
Temporal attention, the prioritization of information at specific points in time, improves performance in behavioral tasks but cannot ameliorate the perceptual asymmetries that exist across the visual field. That is, even after attentional deployment, performance is better along the horizontal than vertical meridian and worse at the upper than lower vertical meridian. Here we asked whether and how microsaccades-tiny fixational eye-movements-could mirror or alternatively attempt to compensate for these performance asymmetries by assessing temporal profiles and direction of microsaccades as a function of visual field location. Observers were asked to report the orientation of one of two targets presented at different time points, in one of three blocked locations (fovea, right horizontal meridian, upper vertical meridian). We found the following: (1) Microsaccade occurrence did not affect either task performance or the magnitude of the temporal attention effect. (2) Temporal attention modulated the microsaccade temporal profiles, and this modulation varied with polar angle location. At all locations, microsaccade rates were significantly more suppressed in anticipation of the target when temporally cued than in the neutral condition. Moreover, microsaccade rates were more suppressed during target presentation in the fovea than in the right horizontal meridian. (3) Across locations and attention conditions, there was a pronounced bias toward the upper hemifield. Overall, these results reveal that temporal attention benefits performance similarly around the visual field, microsaccade suppression is more pronounced for attention than expectation (neutral trials) across locations, and the directional bias toward the upper hemifield could reflect an attempt to compensate for typical poor performance at the upper vertical meridian.
时间注意，即在特定时间优先处理信息，可提高行为任务的表现，但无法改善整个视野中存在的感知偏侧性。也就是说，即使在注意力分配之后，水平方向上的表现仍优于垂直方向，而垂直方向上的上部又比下部差。在这里，我们想知道微扫视（微小的注视性眼球运动）是否可以反映或尝试弥补这些表现偏侧性，方法是评估微扫视的时间分布和方向作为视野位置的函数。要求观察者报告在不同时间点呈现的两个目标之一的方向，目标出现在三个被试分区（中央凹、右水平子午线、上垂直子午线）之一。我们发现：（1）微扫视的发生并不影响任务表现或时间注意效应的幅度。（2）时间注意调制了微扫视的时间分布，这种调制随极角位置而变化。在所有位置，与中性条件相比，当目标受到时间提示时，微扫视的发生率明显受到抑制。此外，在中央凹处，微扫视的发生率在目标呈现期间比在右水平子午线处受到更大的抑制。（3）在所有位置和注意条件下，都存在对上半视野的明显偏向。总的来说，这些结果表明，时间注意在视野周围以相似的方式有益于表现，微扫视抑制在注意力条件下比在期望（中性试验）条件下更为明显，而上半视野的定向偏向可能反映了对上半垂直子午线表现不佳的尝试补偿。
