Biology subjects

Caprara, I.

Publications and source records attributed to Caprara, I..

6 recordsLinked to original sources

bioRxiv2026

Stabilization-Responsiveness Trade-offs in Continuous Shared-Control for Invasive Brain-Computer Interfaces

Intracortical brain-computer interfaces (iBCIs) can enable people with paralysis to control assistive devices, but reliable operation in dynamic environments remains limited by fluctuations in decoded neural commands. Here we develop a confidence-modulated AI-brain shared-control framework in which an artificial intelligence copilot adaptively integrates the decoded neural commands with a probabilistic temporal prior to stabilize execution while preserving user intent. In two macaques performing closed-loop virtual navigation tasks in complex environments, shared-control nearly eliminated execution-level failures, including obstacle collisions and target overshoot, while maintaining the directional structure of neural commands. Abrupt target changes revealed a boundary condition: temporal stabilization transiently delays responsiveness when recent history was no longer predictive. Offline replay showed that resetting the temporal prior eliminated this lag and restored performance, demonstrating that the impairment was algorithmic rather than a failure of neural decoding. These results provide a mechanistic characterization of confidence-modulated AI-brain shared control for continuous intracortical BCI navigation and identify design principles for safer and more reliable neuroprosthetic control in dynamic environments.

neuroscience↗

bioRxiv2023

DREDge: robust motion correction for high-density extracellular recordings across species

High-density microelectrode arrays (MEAs) have opened new possibilities for systems neuroscience in human and non-human animals, but brain tissue motion relative to the array poses a challenge for downstream analyses, particularly in human recordings. We introduce DREDge (Decentralized Registration of Electrophysiology Data), a robust algorithm which is well suited for the registration of noisy, nonstationary extracellular electrophysiology recordings. In addition to estimating motion from spikes in the action potential (AP) frequency band, DREDge enables automated tracking of motion at high temporal resolution in the local field potential (LFP) frequency band. In human intraoperative recordings, which often feature fast (period <1s) motion, DREDge correction in the LFP band enabled reliable recovery of evoked potentials, and significantly reduced single-unit spike shape variability and spike sorting error. Applying DREDge to recordings made during deep probe insertions in nonhuman primates demonstrated the possibility of tracking probe motion of centimeters across several brain regions while simultaneously mapping single unit electrophysiological features. DREDge reliably delivered improved motion correction in acute mouse recordings, especially in those made with an recent ultra-high density probe. We also implemented a procedure for applying DREDge to recordings made across tens of days in chronic implantations in mice, reliably yielding stable motion tracking despite changes in neural activity across experimental sessions. Together, these advances enable automated, scalable registration of electrophysiological data across multiple species, probe types, and drift cases, providing a stable foundation for downstream scientific analyses of these rich datasets.

neuroscience↗

bioRxiv2022

Robust online multiband drift estimation in electrophysiology data

High-density electrophysiology probes have opened new possibilities for systems neuroscience in human and non-human animals, but probe motion (or drift) while recording poses a challenge for downstream analyses, particularly in human recordings. Here, we improve on the state of the art for tracking this drift with an algorithm termed DREDge (Decentralized Registration of Electrophysiology Data) with four major contributions. First, we extend previous decentralized methods to exploit multiband information, leveraging the local field potential (LFP), in addition to spikes detected from the action potentials (AP). Second, we show that the LFP-based approach enables registration at sub-second temporal resolution. Third, we introduce an efficient online motion tracking algorithm, allowing the method to scale up to longer and higher spatial resolution recordings, which could facilitate real-time applications. Finally, we improve the robustness of the approach by accounting for the nonstationarities that occur in real data and by automating parameter selection. Together, these advances enable fully automated scalable registration of challenging datasets from both humans and mice.

neuroscience↗

bioRxiv2020

Temporal dynamics of neural activity in macaque frontal cortex assessed with large-scale recordings

We make eye movements to objects before grasping these objects, and the gaze direction generally indicates where the object will be grasped. Hence, the brain has to coordinate eye-, arm- and hand movements. We performed large-scale recordings (more than 2000 responsive sites) in frontal cortex of monkeys during a saccade-reach-grasp task. When an object appeared in peripheral vision, the first burst of activity emerged in prearcuate areas (the FEF and area 45B), followed by dorsal and ventral premotor cortex, and a buildup of activity in primary motor cortex. After the saccade, prearcuate activity remained elevated while primary motor and premotor activity rose in anticipation of the upcoming arm and hand movement. Some premotor and prearcuate sites were equally active when the object appeared in peripheral vision and at the fovea, suggesting a role in eye-hand coordination. Thus, a large part of lateral frontal cortex is active during a saccade-reach-grasp task.

neuroscience↗

bioRxiv2020

The causal role of three frontal cortical areas in grasping

Efficient object grasping requires the continuous control of arm and hand movements based on visual information. Previous studies have identified a network of parietal and frontal areas that is crucial for the visual control of prehension movements. Electrical microstimulation of 3D shape-selective clusters in AIP during fMRI activates areas F5a and 45B, suggesting that these frontal areas may represent important downstream areas for object processing during grasping, but the role of area F5a and 45B in grasping is unknown. To assess their causal role in the frontal grasping network, we reversibly inactivated 45B, F5a and F5p during visually-guided grasping in macaque monkeys. First, we recorded single neuron activity in 45B, F5a and F5p to identify sites with object responses during grasping. Then, we injected muscimol or saline to measure the grasping deficit induced by the temporary disruption of each of these three nodes in the grasping network. The inactivation of all three areas resulted in a significant increase in the grasping time in both animals, with the strongest effect observed in area F5p. These results not only confirm a clear involvement of F5p, but also indicate causal contributions of area F5a and 45B in visually-guided object grasping.

neuroscience↗

bioRxiv2020

Effect of viewing distance on object responses in macaque areas 45B, F5a and F5p

To perform real-world tasks like grasping, the primate brain has to process visual object information so that the grip aperture can be adjusted before contact with the object is made. Previous studies have demonstrated that the posterior subsector of the Anterior Intraparietal area (pAIP) is connected to frontal area 45B, and the anterior subsector of AIP (aAIP) to F5a (Premereur et al., 2015). However, the role of area 45B and F5a in visually-guided object grasping is poorly understood. Here, we investigated the role of area 45B, F5a and F5p in visually-guided grasping. If a neuronal response to an object during passive fixation represents the activation of a motor command related to the preshaping of the hand, such neurons should prefer objects presented within reachable distance. Conversely, neurons encoding a pure visual representation of an object should be less affected by viewing distance. Contrary to our expectations, we found that the majority of neurons in area 45B were object- and viewing distance selective, with a clear preference for the near viewing distance. Area F5a showed much weaker object selectivity compared to 45B, with a similar preference for objects presented at the Near position emerging mainly in the late epoch. Finally, F5p neurons were less object selective and frequently preferred objects presented at the Far position. Therefore, contrary to our expectations, neurons in area 45B - but not F5p neurons - prefer objects presented in peripersonal space. Significance statementThe current experiment provides the first evidence on the neural representation of distance in frontal areas that are active during visually-guided grasping. Area 45B and F5a neurons were object- and distance-selective, and preferred the near viewing distance even for objects with identical retinal size. In area F5p we observed strong visual responses with an unexpected preference for the Far viewing distance, suggesting that the motor-related object representation was still active during the presentation of objects outside reaching distance.

neuroscience↗