Lee Abigail R I, Ales Justin M, Harris Julie M
Centre for Vision Research, York University, Toronto, ON M3J 1P3, Canada.
School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK.
Vision (Basel). 2020 Jul 6;4(3):33. doi: 10.3390/vision4030033.
Judging the speed of objects moving in three dimensions is important in our everyday lives because we interact with objects in a three-dimensional world. However, speed perception has been seldom studied for motion in depth, particularly when using monocular cues such as looming. Here, we compared speed discrimination, and speed change discrimination, for looming stimuli, in order to better understand what visual information is used for these tasks. For the speed discrimination task, we manipulated the distance and duration information available, in order to investigate if participants were specifically using speed information. For speed change discrimination, total distance and duration were held constant; hence, they could not be used to successfully perform that task. For the speed change discrimination task, our data were consistent with observers not responding specifically to speed changes within an interval. Instead, they may have used alternative, arguably less optimal, strategies to complete the task. Evidence suggested that participants used a variety of cues to complete the speed discrimination task, not always solely relying on speed. Further, our data suggested that participants may have switched between cues on a trial to trial basis. We conclude that speed changes in looming stimuli were not used in a speed change discrimination task, and that naïve participants may not always exclusively use speed for speed discrimination.
在我们的日常生活中，判断三维空间中物体的运动速度非常重要，因为我们在三维世界中与物体进行交互。然而，对于深度运动的速度感知研究很少，特别是在使用诸如逼近等单眼线索时。在这里，我们比较了逼近刺激的速度辨别和速度变化辨别，以便更好地了解用于这些任务的视觉信息。对于速度辨别任务，我们操纵了可用的距离和持续时间信息，以调查参与者是否专门使用速度信息。对于速度变化辨别，总距离和持续时间保持不变；因此，它们不能用于成功完成该任务。对于速度变化辨别任务，我们的数据与观察者未对间隔内的速度变化做出特定反应一致。相反，他们可能使用了其他可以说是不太理想的策略来完成任务。有证据表明，参与者使用了各种线索来完成速度辨别任务，并不总是仅仅依赖速度。此外，我们的数据表明，参与者可能在每次试验中在不同线索之间切换。我们得出结论，在速度变化辨别任务中未使用逼近刺激中的速度变化，并且未经训练的参与者在速度辨别时可能并不总是仅使用速度。
