Biology subjects

Wali, M.

Publications and source records attributed to Wali, M..

5 recordsLinked to original sources

bioRxiv2025

Frontal and Parietal Contributions to Proprioception and Motor Skill Learning

Motor skill learning is the process of developing new movements with practice until they can be performed automatically. This necessitates the interaction of high-level cognitive processes with low-level sensorimotor mechanisms. Skill learning involves not only changes in the motor system but also proprioception (position sense). Proprioceptive deficits increase variability and decrease accuracy of movement. The somatosensory cortex, where low-level proprioception is processed, is known to play a role in motor skill learning, but the involvement of higher-level proprioceptive regions is unclear. Dorsolateral prefrontal cortex (DLPFC) has been linked to the high-level early stages of motor learning, and indirectly to proprioception. Supramarginal gyrus (SMG), an interface area between motor and sensory cortices, has been linked to higher-order proprioceptive processing. In this study, we asked how activity in DLPFC and SMG influences motor skill learning. Participants learned an upper limb motor skill designed to be spatially complex and dependent on proprioception: tracing a two-dimensional maze as accurately as possible within the desired speed range, using a KINARM Endpoint robotic manipulandum. Proprioceptive acuity (sensitivity and bias) was assessed before and after continuous theta burst transcranial magnetic stimulation (cTBS) was applied to inhibit activity in DLPFC, SMG, or Sham. To measure motor skill, movement accuracy and variability were examined at the trained speed as well as at a faster (more difficult) and a slower (easier) speed. Skill was assessed before and after cTBS, after 40 training trials (early learning) and after another 80 trials (late learning). All three groups showed improvements in movement accuracy and variance, indicating they learned the maze tracing skill. However, the Sham group improved movement variability at the faster speed significantly more than the DLPFC or SMG groups did. This suggests that DLPFC and SMG are important for the more challenging aspects of motor skill learning, consistent with their association with higher-level proprioceptive function.

neuroscience↗

bioRxiv2025

Network dynamics for sensory prioritization: Functional connectivity related to individual sensory weighting of vision versus proprioception during upper limb control

Precise control of the hand requires the dynamic integration of visual and proprioceptive (body position sense) sensory cues with internal models, task goals, and motor plans. Individual differences in how visual and proprioceptive cues are weighted have been related to neural substrates, such as posterior parietal regions, yet the underlying neural dynamics are unclear. This study investigated the relationship between visuo-proprioceptive perception during a bimanual pointing task and the whole-brain network dynamics using resting-state functional magnetic resonance imaging (rsfMRI) with both atlas-based and individually-localized ROI seeds. Our results confirm the existence of individual sensory biases, and find they have systematic influences on functional connectivity. Activity between sensorimotor regions and default mode network (DMN) nodes was related to sensory weighting (e.g. individual degree of reliance on vision versus proprioception) and may reflect updating of internal models. The ventral premotor cortex (PMv) emerged as an important node with functional connections suggesting its role for integrating motor plans, internal models, and sensory percepts. Connections from multisensory integration regions like the middle temporal gyrus (MTG) and the superior parietal lobule (SPL), and motor coordination regions in the cerebellum, were related to increased reliance on visual versus proprioceptive information. These findings suggest that individual sensory biases during sensorimotor behavior may be characterized by specific and specialized patterns of neural activity. This research establishes a foundational exploration of the neural systems underlying sensorimotor processing, supporting theories suggesting that learning in either the sensory or motor system may also cause plasticity in the other.

neuroscience↗

bioRxiv2024

Somatosensory cortex and body representation: Updating the motor system during a visuo-proprioceptive cue conflict

The brains representation of hand position is critical for voluntary movement. Representation is multisensory, combining visual and proprioceptive cues. When these cues conflict, the brain recalibrates its unimodal estimates, shifting them closer together to compensate. Converging evidence from research in perception, behavior, and neurophysiology suggest that such updates to body representation are communicated to the motor system to keep hand movements accurate. We hypothesized that primary somatosensory cortex (SI) is crucial in this updating process due to its role in proprioception and connections with primary motor cortex. We tested this hypothesis in two experiments. We predicted that proprioceptive, but not visual, recalibration would be associated with change in short latency afferent inhibition (SAI), a measure of sensorimotor integration (influence of sensory input on motor output) (Expt. 1). We further predicted that modulating SI activity with repetitive transcranial magnetic stimulation (TMS) should affect recalibration of the proprioceptive estimate of hand position, but have no effect on the visual estimate or on the normal inverse relationship between proprioceptive and visual recalibration (Expt. 2). Our results are consistent with these predictions, supporting the idea that (1) SI is indeed a key region in facilitating motor system updates based on changes in body representation, and (2) this function is mediated by unisensory (proprioceptive) processing, separate from multisensory visuo-proprioceptive computations. Other aspects of the body representation (visual and multisensory) may be conveyed to the motor system via separate pathways, e.g. from posterior parietal regions to motor cortex. Significance StatementRepresentation of the hand, which is critical for accurate control of movement, comes from weighting and combining available proprioceptive (position sense) and visual cues. Our results suggest that when the hand representation is modified by introducing a conflict between these cues, the motor system receives updates directly from the primary somatosensory cortex (SI). These updates are specific to the change in proprioceptive representation and are absent when cues are not in conflict. This may represent a unisensory pathway to the motor system that conveys information about hand representation, acting in parallel with multisensory pathways involving posterior parietal and premotor regions.

neuroscience↗

bioRxiv2023

CyVerse: Cyberinfrastructure for Open Science

CyVerse, the largest publicly-funded open-source research cyberinfrastructure for life sciences, has played a crucial role in advancing data-driven research since the 2010s. As the technology landscape evolved with the emergence of cloud computing platforms, machine learning and artificial intelligence (AI) applications, CyVerse has enabled access by providing interfaces, Software as a Service (SaaS), and cloud-native Infrastructure as Code (IaC) to leverage new technologies. CyVerse services enable researchers to integrate institutional and private computational resources, custom software, perform analyses, and publish data in accordance with open science principles. Over the past 13 years, CyVerse has registered more than 110,000 verified accounts from 160 countries and was used for over 1,600 peer-reviewed publications. Since 2011, 45,000 students and researchers have been trained to use CyVerse. The platform has been replicated and deployed in two countries outside the US, with additional private deployments on commercial clouds for US government agencies and multinational corporations. In this manuscript, we present a strategic blueprint for creating and managing SaaS cyberinfrastructure and IaC as free and open-source software.

scientific communication and education↗

bioRxiv2022

Retention of visuo-proprioceptive recalibration in estimating hand position

The brain estimates hand position using visual and proprioceptive cues, which are combined to give an integrated multisensory estimate. Spatial mismatches between cues elicit recalibration, a compensatory process where each unimodal estimate is shifted closer to the other. It is unclear how well visuo-proprioceptive recalibration is retained after mismatch exposure. Here we asked whether direct vision and/or active movement of the hand can undo visuo-proprioceptive recalibration, and whether recalibration is still evident 24 hours later. 75 participants performed two blocks of visual, proprioceptive, and combination trials, with no feedback or direct vision of the hand. In Block 1, a 70 mm visuo-proprioceptive mismatch was gradually imposed, and recalibration assessed. Block 2 tested retention. Between blocks, Groups 1-4 rested or made active movements with their directly visible or unseen hand for several minutes. Group 5 had a 24-hour gap between blocks. All five groups recalibrated both vision and proprioception in Block 1, and Groups 1-4 retained most of this recalibration in Block 2. Interestingly, Group 5 showed an offline increase in proprioceptive recalibration, but retained little visual recalibration. Our results suggested that visuo-proprioceptive recalibration is robustly retained in the short-term. In the longer term, contextual factors may affect retention.

neuroscience↗