Tomonaga Masaki, Tanaka Yoshihiro, Sakai Motoyuki
University of Human Environments, Matsuyama, Ehime, 790-0825, Japan.
Nagoya Institute of Technology, Showa-ku, Nagoya, Aichi, 466-8555, Japan.
Primates. 2024 Mar;65(2):89-101. doi: 10.1007/s10329-023-01117-1. Epub 2024 Jan 20.
While force-feedback devices have been developed in areas such as virtual reality, there have been very few comparative cognitive studies in nonhuman animals using these devices. In addition, although cross-modal perception between vision and touch has been actively studied in nonhuman primates for several decades, there have been no studies of their active haptic perception. In this study, we attempted to train force discrimination in chimpanzees using a force-feedback device modified from a trackball. Chimpanzees were given different levels of force feedback (8.0 vs. 0.5 N) when moving the on-screen cursor to the target area by manipulating the trackball and were required to select one of two choice stimuli based on the force cue. The experiment was conducted using a trial-block procedure in which the same force stimulus was presented for a fixed number of trials, and the force stimulus was changed between blocks. The block size was progressively reduced from ten trials. Four chimpanzees were trained, but none reached the learning criterion (80% or more correct responses under the condition that the force stimuli were presented randomly). However, a detailed analysis of the chimpanzees' performance before and after the trial-block switching revealed that their choice behavior could not be explained by a simple win-stay/lose-shift strategy, suggesting that the switching of the force stimuli affected the chimpanzees' choice behavior. It was also found that the chimpanzees performed better when switching from small to large force stimuli than when switching from large to small force stimuli. Although none of the chimpanzees in this study acquired force discrimination, future studies using such force-feedback devices will provide new insights for understanding haptic cognition in nonhuman primates from a comparative cognitive perspective.
虽然力反馈设备已在虚拟现实等领域得到开发，但在非人类动物中使用这些设备进行的比较认知研究却非常少。此外，尽管视觉与触觉之间的跨模态感知在非人类灵长类动物中已经被积极研究了几十年，但尚未有关于它们主动触觉感知的研究。在本研究中，我们尝试使用从轨迹球改装而来的力反馈设备训练黑猩猩进行力的辨别。当黑猩猩通过操纵轨迹球将屏幕上的光标移动到目标区域时，会给予它们不同水平的力反馈（8.0牛与0.5牛），并要求它们根据力的线索从两个选择刺激中选择其一。实验采用试块程序进行，即对相同的力刺激呈现固定次数的试验，并且在不同试块之间改变力刺激。试块大小从十次试验开始逐渐减小。对四只黑猩猩进行了训练，但没有一只达到学习标准（在力刺激随机呈现的条件下，正确反应达到80%或更高）。然而，对黑猩猩在试块切换前后表现的详细分析表明，它们的选择行为不能用简单的赢则保留/输则转换策略来解释，这表明力刺激的切换影响了黑猩猩的选择行为。还发现，与从大力刺激切换到小力刺激相比，黑猩猩从小力刺激切换到大力刺激时表现更好。尽管本研究中的黑猩猩没有一只获得力的辨别能力，但未来使用此类力反馈设备的研究将从比较认知的角度为理解非人类灵长类动物的触觉认知提供新的见解。
