Junjun Chen1,2 · Guanghao Sun1,3 · Yiwei Zhang1,3 · Weidong Chen1 · Xiaoxiang Zheng1,3 · Shaomin Zhang1,4 · Yaoyao Hao1,3,4
1 Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou 310027, China
2 School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao 266114, China
3 Department of Biomedical Engineering, Zhejiang University, Hangzhou 310027, China
4 The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou 311100, China
Abstract
Reach-to-grasp movements require integrating information on both object location and grip type, but how these elements are planned and to what extent they interact remains unclear. We designed a new experimental paradigm in which monkeys sequentially received reach and grasp cues with delays, requiring them to retain and integrate both cues to grasp the goal object with appropriate hand gestures. Neural activity in the dorsal premotor cortex (PMd) revealed that reach and grasp were similarly represented yet not independent. Upon receiving the second cue, the PMd continued encoding the first, but over half of the neurons displayed incongruent modulations: enhanced, attenuated, or even reversed. Population-level analysis showed significant changes in encoding structure, forming distinct neural patterns. Leveraging canonical correlation analysis, we identified a shared subspace preserving the initial cue’s encoding, contributed by both congruent and incongruent neurons. Together, these findings reveal a novel perspective on the interactive planning of reach and grasp within the PMd, providing insights into potential applications for brain–machine interfaces.
Keywords
Reach-to-grasp; Dorsal premotor cortex; Motor planning; Interactive encoding; Canonical correlation analysis; Macaque monkey
