Biology subjects

de la Malla, C.

Publications and source records attributed to de la Malla, C..

4 recordsLinked to original sources

bioRxiv2026

Tracking the hidden dynamics of proprioception

Every movement unfolds with a simple question: Where is my body? The nervous system answers through proprioception - the sense of limb position (static position sense) and movement (dynamic proprioception). Although position sense has been well characterized, dynamic proprioception has remained difficult to isolate and measure. Here we introduce a continuous proprioceptive tracking paradigm, coupled with computational modelling, that captures dynamic proprioception in real time. We first establish that this approach is sensitive, reliable and efficient. Leveraging this method, we then show that dynamic proprioception provides faster and more faithful estimates of limb state than vision, dominates multisensory state estimation when vision is also available, and is not correlated with conventional measures of position sense. Together, these findings provide a new quantitative framework for characterizing dynamic proprioception in health and disease.

neuroscience↗

bioRxiv2026

Torsion in motion: the visual system as a three-axis gimbal

Rigorously tracking eye and head behavior in space is key to building realistic models of the stimulus that reaches our retina. The motion structure of this stimulus or retinal flow - the substrate for self-motion processing - is created by the relative movement of the eyes with respect to the world. Characterizing this stimulus requires tracking the eye's three degrees of freedom in the head and the head's six degrees of freedom in the world. While vertical and horizontal eye rotations have been described during locomotion in the context of gaze stabilization, the component around the line of sight - torsion - has remained difficult to quantify, and how all three rotational components jointly contribute to retinal flow during self-motion remains largely unexplored. Here, we leveraged head-mounted technology to estimate eye torsion in ten subjects as they walked towards a distant target (from 14 to 4 meters away from the target). More specifically, we combined automatic feature tracking with gaze-constrained simulations of eye rotations and camera projection to recover torsion from image data. We then estimated the curl present in the optic-flow field in head and retina centered frames in two scenarios: torsion as estimated from our data and with no torsion. We show that the eye's torsional component compensates for the roll component of head's angular displacement, altering the incoming visual flow in ways that are relevant for the extraction of self-motion parameters from retinal flow.

animal behavior and cognition↗

bioRxiv2025

Target configuration determines how and what we learn during sensorimotor adaptation

Motor adaptation--the process of correcting movement errors through feedback and practice--is a fundamental human capacity that keeps our actions well-calibrated amid changes in the environment and the body. However, how training context--specifically, the configuration of targets in the workspace--shapes how we learn and what we learn during motor adaptation remains unknown. To investigate this, we conducted two reaching experiments in which participants experienced a visuomotor gain perturbation, with feedback scaled to 1.3x (Exp 1) or 0.7x (Exp 2) the actual movement distance. In both experiments, participants were assigned to either the Extent Group, which trained with targets of varying amplitudes in a single direction, or the Angular Group, which trained with targets of equal amplitude in different directions. We found marked differences in how the two groups learned: the Angular Group learned more implicitly than the Extent Group, as evidenced by larger post-perturbation aftereffects when participants were instructed to forgo re-aiming strategies. Just as striking were the differences in what the two groups learned: the Angular Group learned a translation rule, which generalized to new directions but not amplitudes, while the Extent Group learned the imposed gain rule, which generalized to new amplitudes but not directions. Together, these findings underscore the importance of training context in determining how and what we learn.

neuroscience↗

bioRxiv2020

Visuomotor temporal adaptation is tuned to gamma brain oscillatory coherence

Every time we use our smartphone, tablet, or other electronic devices we are exposed to temporal delays between our actions and the sensory feedback. We can compensate for such delays by adjusting our motor commands and doing so likely requires establishing new temporal mappings between motor areas and sensory predictions. However, little is known about the neural underpinnings that would support building new temporal correspondences between different brain areas. We here address the possibility that communication through coherence, which is thought to support neural interareal communication, lies behind the neural processes accounting for how humans cope with additional delays between motor and sensory areas. We recorded EEG activity while participants intercepted moving targets while seeing a cursor that followed their hand with a delay rather than their own hand. Participants adjusted their movements to the delayed visual feedback and intercepted the target with the cursor. The EEG data shows a significant increase in coherence of beta and gamma bands between visual and motor areas during the hand on-going movement towards interception. However, when looking at differences between participants depending on the level of adaptation, only the increase in gamma band correlated with the level of temporal adaptation. We are able to describe the time course of the coherence using coupled oscillators showing that the times at which high coherence is achieved are within useful ranges to solve the task. Altogether, these results evidence the functional relevance of brain coherence in a complex task where adapting to new delays is crucial. AUTHOR SUMMARYHumans are often exposed to delays between their actions and the incoming sensory feedback caused by actions. While there have been advances in the understanding of the conditions at which temporal adaptation can occur, little is known about the neural mechanisms enabling temporal adaptation. In the present study we measure brain activity (EEG) to investigate whether communication through coherence between motor and sensory areas might be responsible for ones ability to cope with externally imposed delays in an interception task. We show evidence that neural coherence at gamma band between visual and motor areas is related to the degree of adaptation to temporal delays.

neuroscience↗