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Motor learning in visuomotor adaptation tasks results from both explicit and implicit processes, each responding differently to an error signal. Although the motor output side of these processes has been extensively studied, the visual input side is relatively unknown. We investigated if and how depth perception affects the computation of error information by explicit and implicit motor learning. Two groups of participants made reaching movements to bring a virtual cursor to a target in the frontoparallel plane. The Delayed group was allowed to reaim and their feedback was delayed to emphasize explicit learning, whereas the camped group received task-irrelevant clamped cursor feedback and continued to aim straight at the target to emphasize implicit adaptation. Both groups played this game in a highly detailed virtual environment (depth condition), leveraging a cover task of playing darts in a virtual tavern, and in an empty environment (no-depth condition). The delayed group showed an increase in error sensitivity under depth relative to no-depth. In contrast, the clamped group adapted to the same degree under both conditions. The movement kinematics of the delayed participants also changed under the depth condition, consistent with the target appearing more distant, unlike the Clamped group. A comparison of the delayed behavioral data with a perceptual task from the same individuals showed that the greater reaiming in the depth condition was consistent with an increase in the scaling of the error distance and size. These findings suggest that explicit and implicit learning processes may rely on different sources of perceptual information. NEW & NOTEWORTHY We leveraged a classic sensorimotor adaptation task to perform a first systematic assessment of the role of perceptual cues in the estimation of an error signal in the 3-D space during motor learning. We crossed two conditions presenting different amounts of depth information, with two manipulations emphasizing explicit and implicit learning processes. Explicit learning responded to the visual conditions, consistent with perceptual reports, whereas implicit learning appeared to be independent of them.
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This content will become publicly available on September 1, 2026
Emergent motor timing enhances time perception
Precise timing underlies many behaviors, from musical performance to navigating a dynamic environment. This study examined how stable temporal patterns that emerge during goal-directed movements influence timing acuity in perceptual discrimination. Rather than relying on explicitly timed actions, we used a selfpaced throwing task in which temporal structure develops implicitly with practice. Across three experiments, participants were trained for four days, developing stable motor timing reflected in consistent ‘‘ball release times.’’ This emergent timing selectively enhanced sensitivity to matching temporal intervals in a perceptual discrimination task. Importantly, this effect was not explained by perceptual learning and persisted over several weeks, suggesting a durable motor-perceptual linkage. The results point to a shared representation of time in action and perception, an emergent timing primitive that arises through experience in spatiotemporal movements. These findings shed light on how motor learning can shape temporal perception in ecologically relevant contexts, with implications for rehabilitation and sensorimotor integration.
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- Award ID(s):
- 2043318
- PAR ID:
- 10647128
- Publisher / Repository:
- Cell Press
- Date Published:
- Journal Name:
- iScience
- Volume:
- 28
- Issue:
- 9
- ISSN:
- 2589-0042
- Page Range / eLocation ID:
- 113367
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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