Characteristics of Tactile Orientation Perception: Oblique Effect, Active vs Passive Exploration, and Serial Dependence

Abstract

Orientation perception is one of the most fundamental aspects of somatosensory perception, similar to its visual counterpart. In the current study, we examined several features of tactile orientation perception and their interactions, aiming to better understand the underlying mechanisms. We found that active exploration exhibits better orientation acuity compared to passive exploration. We also observed an exploration-independent and paradigm-independent robust anisotropy (i.e., tactile oblique effect) in tactile orientation acuity where the proximal-distal axis demonstrates superior orientation acuity compared to oblique and medial-lateral orientations. Finally, we demonstrated that, similar to its visual counterpart, tactile orientation perception showed a systematic attractive serial dependence effect, in which current orientation perception is biased towards the previous trial. However, this attractive effect is driven by post-perceptual processing/response rather than the stimulus per se.