Tanriverdi Dilce, Cornelissen Frans W
Laboratory for Experimental Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
https://orcid.org/0000-0002-6898-3811.
J Vis. 2025 Jun 2;25(7):7. doi: 10.1167/jov.25.7.7.
Visual crowding refers to the difficulty in recognizing objects in the periphery when surrounded by clutter. Traditional trial-based paradigms, while effective in measuring spatial aspects of crowding, do not capture the temporal dynamics involved. In this study, we assessed the feasibility of a continuous psychophysics paradigm that measures both the spatial extent and temporal processes of visual crowding. Eight participants continuously tracked the orientation of a rotating Landolt C while the distance between the target and a ring-shaped flanker varied systematically over time. Participants set a reference stimulus to match the orientation of the target. The paradigm included "jump-points," where the orientation of the target suddenly shifted, allowing us to measure the recovery rate of participants' tracking errors following these disruptions. Tracking accuracy was compared between flanked and isolated conditions. Additionally, participants' report errors were used to assess both the crowding extent and the temporal recovery rate from the jumps, with the crowding extent results compared with those obtained from a conventional trial-based version of the paradigm. The recovery rate was calculated by fitting an exponential decay function to participants' report errors after the jumps. The results showed that the crowding extent measured using the continuous paradigm was consistent with that obtained using trial-based methods and aligned with Bouma's rule. Moreover, flankers decreased both tracking accuracy and recovery rate following the jumps. These results demonstrate that our continuous psychophysics paradigm is useful for measuring the spatiotemporal aspects of crowding.
视觉拥挤是指当被杂乱物体包围时，在周边区域识别物体的困难。传统的基于试次的范式虽然在测量拥挤的空间方面有效，但并未捕捉到其中涉及的时间动态。在本研究中，我们评估了一种连续心理物理学范式的可行性，该范式可测量视觉拥挤的空间范围和时间过程。八名参与者持续跟踪一个旋转的兰多尔特C的方向，同时目标与环形侧翼刺激之间的距离随时间系统地变化。参与者设置一个参考刺激来匹配目标的方向。该范式包括“跳变点”，即目标方向突然改变，使我们能够测量这些干扰后参与者跟踪误差的恢复率。比较了有侧翼刺激和无侧翼刺激条件下的跟踪准确性。此外，参与者的报告误差用于评估拥挤程度和跳变后的时间恢复率，将拥挤程度结果与从该范式的传统基于试次版本获得的结果进行比较。通过对跳变后参与者的报告误差拟合指数衰减函数来计算恢复率。结果表明，使用连续范式测量的拥挤程度与使用基于试次方法获得的结果一致，并且符合布马法则。此外，侧翼刺激在跳变后降低了跟踪准确性和恢复率。这些结果表明，我们的连续心理物理学范式可用于测量拥挤的时空方面。
