Ciria Alejandra, López Florente, Lara Bruno
Facultad de Psicología, Universidad Nacional Autónoma de México, Mexico City, Mexico.
Laboratorio de Robótica Cognitiva, Centro de Investigación en Ciencias, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico.
Front Psychol. 2019 Mar 6;10:490. doi: 10.3389/fpsyg.2019.00490. eCollection 2019.
Perception of time is susceptible to distortions; among other factors, it has been suggested that the perceived duration of a stimulus is affected by the observer's expectations. It has been hypothesized that the duration of an oddball stimulus is overestimated because it is unexpected, whereas repeated stimuli have a shorter perceived duration because they are expected. However, recent findings suggest instead that fulfilled expectations about a stimulus elicit an increase in perceived duration, and that the oddball effect occurs because the oddball is a target stimulus, not because it is unexpected. Therefore, it has been suggested that top-down attention is sometimes sufficient to explain this effect, and sometimes only necessary, with an additional contribution from saliency. However, how the expectedness of a target stimulus and its salient features affect its perceived duration is still an open question. In the present study, participants' expectations about and the saliency of target stimuli were orthogonally manipulated with stimuli presented on a short (Experiment 1) or long (Experiment 2) temporal scale. Four repetitive standard stimuli preceded each target stimulus in a task in which participants judged whether the target was longer or shorter in duration than the standards. Engagement of top-down attention to target stimuli increased their perceived duration to the same extent irrespective of their expectedness. A small but significant additional contribution to this effect from the saliency of target stimuli was dependent on the temporal scale of stimulus presentation. In Experiment 1, saliency only significantly increased perceived duration in the case of expected target stimuli. In contrast, in Experiment 2, saliency exerted a significant effect on the overestimation elicited by unexpected target stimuli, but the contribution of this variable was eliminated in the case of expected target stimuli. These findings point to top-down attention as the primary cognitive mechanism underlying the perceptual extraction and processing of task-relevant information, which may be strongly correlated with perceived duration. Furthermore, the scalar properties of timing were observed, favoring the pacemaker-accumulator model of timing as the underlying timing mechanism.
对时间的感知容易受到扭曲；在其他因素中，有人提出刺激的感知持续时间会受到观察者预期的影响。据推测，异常刺激的持续时间被高估是因为它出乎意料，而重复刺激的感知持续时间较短是因为它们在意料之中。然而，最近的研究结果表明，对刺激的预期实现反而会导致感知持续时间增加，而且异常刺激效应的出现是因为异常刺激是目标刺激，而不是因为它出乎意料。因此，有人提出自上而下的注意力有时足以解释这种效应，有时只是必要条件，还需要显著性的额外作用。然而，目标刺激的预期性及其显著特征如何影响其感知持续时间仍是一个悬而未决的问题。在本研究中，通过在短（实验1）或长（实验2）时间尺度上呈现刺激，对参与者对目标刺激的预期和显著性进行了正交操纵。在一项任务中，每个目标刺激之前有四个重复的标准刺激，参与者判断目标刺激的持续时间比标准刺激长还是短。无论目标刺激的预期性如何，自上而下对目标刺激的注意力参与都会使其感知持续时间增加到相同程度。目标刺激的显著性对这种效应有一个小但显著的额外作用，这取决于刺激呈现的时间尺度。在实验1中，显著性仅在预期目标刺激的情况下显著增加了感知持续时间。相比之下，在实验2中，显著性对意外目标刺激引起的高估有显著影响，但在预期目标刺激的情况下，该变量的作用被消除。这些发现表明，自上而下的注意力是感知提取和处理与任务相关信息的主要认知机制，这可能与感知持续时间密切相关。此外，观察到了时间的标量特性，支持起搏器-累加器时间模型作为潜在的时间机制。
