Biology subjects

Genovese, F.

Publications and source records attributed to Genovese, F..

5 recordsLinked to original sources

bioRxiv2025

ACTION ENHANCEMENT DRIVES THE EMBODIMENT OF A SUPERNUMERARY ROBOTIC DIGIT

Wearable robotic supernumerary limbs enhance motor capabilities by leveraging principles from both engineering and neuroscience. Despite extensive research, how supernumerary limbs become embodied and the relationship between embodiment and artificially enhanced action possibilities remain largely unexplored. This gap has implications for device design and clinical adoption, as embodiment likely promotes patients acceptance and daily use of their supernumerary limb. Using an adapted proprioceptive drift paradigm from rubber hand illusion research, we investigated the embodiment of a robotic Soft Sixth Finger (SSF). Participants performed grasp-to-lift actions versus mere lift actions without object interaction, wearing the SSF on two different configurations: the palm and back of the hand. The Palm condition involved achievable actions without the SSF, while the Dorsal condition enabled otherwise anatomically impossible actions, extending beyond the physiological motor repertoire. Hand proprioceptive drift was measured before and after each task. Results showed that the SSF impacted body representation only when dorsally mounted. Proprioceptive drift was significantly higher for grasp-to-lift actions in Dorsal versus Palm conditions and higher for grasp-to-lift versus mere lift in the Dorsal condition only. This proves that SSF embodiment relates to extending, rather than substituting, users action possibilities. Future research must integrate behavioral, cognitive, and neural measurements across healthy and patient populations. Our study provides an ideal model for clinical application, demonstrating how enabling otherwise impossible actions drives robotic supernumerary finger embodiment.

neuroscience↗

bioRxiv2025

How Acting Jointly Differs from Acting Side-by-Side: A Dual EEG Study

The distinction between acting jointly and acting side by side permeates our daily lives and is crucial for understanding the evolution and development of human sociality. While acting in parallel involves agents pursuing individual goals, acting jointly requires them to share a collective goal. Here, we used a dual electroencephalography (EEG) approach to explore the neural dynamics underlying joint and parallel action preparation. We recorded event-related potentials (ERPs) from 20 dyads while they had to transport an object in a video game, either jointly or in parallel, or individually. Both conditions were carefully matched for coordination demands and performance complexity, as confirmed by equal success rates. Our results revealed a distinctive pattern swap in ERPs during action preparation. In the early preparation phase, ERPs showed significantly higher amplitude during joint action than parallel action. This pattern reversed in the late preparation phase, with significantly reduced ERP amplitude in the joint compared to parallel action. Notably, the decrease in late ERPs correlated with higher reaction time (RT) variability in partners but not with participants own RT variability. The dynamic swap in neural activity suggests that different cognitive processes operate at distinct stages of action preparation. While initially sharing a collective goal may impose cognitive costs (reflected in higher early ERPs), this is offset by facilitated late action preparation, likely due to enhanced predictability of partners actions. Significance StatementOur study reveals distinct neural signatures differentiating joint from side-by-side actions. Through dual EEG recordings of twenty dyads performing complexity-matched tasks, we identified a distinctive "swap" in event-related potentials during action preparation. Joint actions initially showed higher early-phase amplitudes but significantly reduced late-phase amplitudes compared to parallel actions. Notably, this late-phase reduction correlated specifically with the variability of partners behavior. This suggests that sharing collective goals initially requires cognitive resources but facilitates action preparation through enhanced predictability of partners. These findings provide a neural framework for understanding the distinction between acting jointly and acting in parallel --a distinction that pervades our daily experiences and is crucial for understanding the development and evolution of human sociality.

neuroscience↗

bioRxiv2024

DOES EXPERIENCE MODULATE AUTOMATIC IMITATION? A NEW LOOK

Automatic imitation is a stimulus-response compatibility effect wherein observing an action automatically influences motor performance. However, the mechanism underlying this effect remains controversial. Associative Sequence Learning suggests that automatic imitation arises from contingent visual and motor activity associations. Prior studies have shown that exposure to counter-imitative training can alter these visuomotor associations, suggesting that automatic imitation can be modulated by experience. Here, we aim to bring new insight into how this modulation occurs by exploring the time course of automatic imitation before and after counter-imitative training. If automatic imitation is merely a result of contingent associations, as previously suggested, the effect should consistently be modulated following such training. However, if this is not the case, automatic imitation is not, or not only, a matter of contingent association, at least not as currently understood.

neuroscience↗

bioRxiv2023

Quantifying peripheral modulation of olfaction by trigeminal agonists

In the mammalian nose, two chemosensory systems, the trigeminal and the olfactory mediate the detection of volatile chemicals. Most odorants in fact are able to activate the trigeminal system, and vice versa, most trigeminal agonists activate the olfactory system as well. Although these two systems constitute two separate sensory modalities, trigeminal activation modulates the neural representation of an odor. The mechanisms behind the modulation of olfactory response by trigeminal activation are still poorly understood. In this study, we addressed this question by looking at the olfactory epithelium, where olfactory sensory neurons and trigeminal sensory fibers co-localize and where the olfactory signal is generated. We characterize the trigeminal activation in response to five different odorants by measuring intracellular Ca2+ changes from primary cultures of trigeminal neurons (TGNs). We also measured responses from mice lacking TRPA1 and TRPV1 channels known to mediate some trigeminal responses. Next, we tested how trigeminal activation affects the olfactory response in the olfactory epithelium using electro-olfactogram (EOG) recordings from WT and TRPA1/V1-KO mice. The trigeminal modulation of the olfactory response was determined by measuring responses to the odorant, 2-phenylethanol (PEA), an odorant with little trigeminal potency after stimulation with a trigeminal agonist. Trigeminal agonists induced a decrease in the EOG response to PEA, which depended on the level of TRPA1 and TRPV1 activation induced by the trigeminal agonist. This suggests that trigeminal activation can alter odorant responses even at the earliest stage of the olfactory sensory transduction. Significance StatementMost odorants reaching the olfactory epithelium can simultaneously activate olfactory and trigeminal systems. Although these two systems constitute two separate sensory modalities, trigeminal activation can alter odor perception. Here, we analyzed the trigeminal activity induced by different odorants proposing an objective quantification of their trigeminal potency independent from human perception. We show that trigeminal activation by odorants reduces the olfactory response in the olfactory epithelium and that such modulation correlates with the trigeminal potency of the trigeminal agonist. These results show that the trigeminal system impacts the olfactory response from its earliest stage.

neuroscience↗

bioRxiv2020

Studies of human twins reveal genetic variation that affects dietary fat perception

To learn more about the mechanisms of human dietary fat perception, 398 human twins rated fattiness and liking for six types of potato chips that differed in triglyceride content (2.5, 5, 10, and 15% corn oil); reliability estimates were obtained from a subset (n = 50) who did the task twice. Some chips also had a saturated long-chain fatty acid (hexadecanoic acid, 16:0) added (0.2%) to evaluate its effect on fattiness and liking. We computed the heritability of these measures and conducted a genome-wide association study (GWAS) to identify regions of the genome that co-segregate with fattiness and liking. Perceived fattiness and liking for the potato chips were reliable (r = 0.31-0.62, p < 0.05) and heritable (up to h2 = 0.29, p < 0.001, for liking). Adding hexadecanoic acid to the potato chips significantly increased ratings of fattiness but decreased liking. Twins with the G allele of rs263429 near GATA3-AS1 or the G allele of rs8103990 within ZNF729 reported more liking for potato chips than did twins with the other allele (multivariate GWAS, p < 1x10-5), with results reaching genome-wide suggestive but not significance criteria. Person-to-person variation in the perception and liking of dietary fat was (a) negatively affected by the addition of a saturated fatty acid and (b) related to inborn genetic variants. These data suggest liking for dietary fat is not due solely to fatty acid content and highlight new candidate genes and proteins within this sensory pathway.

genetics↗