Biology subjects

Dominijanni, G.

Publications and source records attributed to Dominijanni, G..

3 recordsLinked to original sources

bioRxiv2026

Sensory and Motor Building Blocks of an Extra Robotic Digit Representation

Supernumerary limbs provide a unique opportunity to ask how the brain represents an entirely novel effector within an existing sensorimotor system. Here, we investigated how primary motor cortex (M1) represents a robotic extra digit (the Third Thumb; Dani Clode Design), and how this representation changes with experience. Using fMRI, we compared participants following short-term exposure with participants who had undergone longitudinal Third Thumb training. The device was controlled by the toes but operated alongside the biological fingers, while its sensory consequences were experienced on the hand. Following prolonged experience, greater activity was elicited in the M1 hand area both during Third Thumb control, and in response to its sensory consequences alone. Multivariate analyses showed that the Third Thumb representation became more distinct from its biological toe controller. Pattern component modelling further showed that the representation could be explained by a combination of its constituent motor and sensory patterns, but their relative contributions changed substantially with experience, from toe-dominated following short-term exposure to sensory-dominated following longitudinal training. These findings suggest that M1 can represent a novel effector through flexible recombination of existing sensorimotor representations, with experience altering how these pre-existing resources contribute to the emerging representation.

neuroscience↗

bioRxiv2025

Motor Learning Outside the Body: Broad Skill Generalisation with an Extra Robotic Limb

Our ability to transfer motor skills across tools and contexts is what makes modern technology usable. The success of motor augmentation devices, such as supernumerary robotic limbs, hinges on users capacity for generalised motor performance. We trained participants over seven days to use an extra robotic thumb (Third Thumb, Dani Clode Design), worn on the right hand and controlled via the toes. We tested whether motor learning was confined to the specific tasks and body parts involved in controlling and interacting with the Third Thumb, or whether it could generalise beyond them. Participants showed broad skill generalisation across tasks, body postures, and even when either the Third Thumb or the controller was reassigned to a different body part, suggesting the development of abstract, body-independent motor representations. Training also reduced cognitive demands and increased the sense of agency over the device. However, participants still preferred using their biological hand over the Third Thumb when given the option, suggesting that factors beyond motor skill generalisation, cognitive effort, and embodiment must be addressed to support the real-world adoption of such technologies.

neuroscience↗

bioRxiv2025

Developing a Sensory Representation of an Artificial Body Part

Somatosensory feedback is essential for motor control, yet artificial limbs are thought to lack such feedback. We investigated how the body and brain gather informative sensory signals from a wearable augmentation interface (a robotic digit for motor augmentation), and whether naturally-mediated feedback can support technological embodiment. Participants intuitively interpreted natural feedback across perceptual tasks, performing comparably to state-of-the-art artificial feedback systems. fMRI revealed an immediate and distinct, topographically-organised representation of the robotic digit. After longitudinal training, this representation was further refined, becoming more similar to the biological digits, which correlated with increased subjective somatosensory embodiment. Our findings demonstrate that wearable devices naturally provide a powerful source of feedback which is immediately integrated with our body. Long-term use can then promote device-embodiment across the sensorimotor hierarchy.

neuroscience↗