Biology subjects

Quarta, E.

Publications and source records attributed to Quarta, E..

5 recordsLinked to original sources

bioRxiv2026

JOINT ACTION AWARENESS IN MACAQUES DURING A MULTIPLAYER VIDEO-GAME CONTEXT

In behavioral neuroscience, research in nonhuman primates often relies on video game like paradigms, including studies of social interaction and joint action. In social studies, establishing whether animals monitor their partner and are aware of their reciprocal interactions in these abstract laboratory settings is essential for interpreting the processes underlying cooperative performance. Here, we examined spontaneous head orienting behavior in two macaques performing a cooperative visuomotor task under highly controlled conditions. The animals sat side by side with their heads unrestrained and used isometric joysticks to control their respective cursors displayed on a shared screen. Depending on trial instructions, they performed either individual actions (SOLO action, SA) or joint actions (JA) to obtain a reward. We quantified spontaneous head rotations toward the partner as an ethologically relevant behavioral indicator of social monitoring. Partner directed head turns occurred more frequently during JA than during SA trials. Crucially, their rate increased with the number of errors made by the partner during JA trials. Together, these findings indicate that macaques monitor their partner during abstract, computer-mediated cooperative interactions and that this monitoring is driven by the performance of the partner. Such spontaneous, context specific orienting toward the partner supports the interpretation that macaques are aware of their dyadic engagement, even in video game like settings. Our results therefore highlight the suitability of controlled visuomotor paradigms for investigating the cognitive-motor processes underlying joint action in nonhuman primates.

neuroscience↗

bioRxiv2025

COSTS AND BENEFITS OF ACTING TOGETHER: A NON-HUMAN PRIMATE MODEL OF COOPERATIVE DECISION-MAKING

Cooperation is a crucial aspect of social behavior, allowing individuals to achieve goals unattainable alone. However, collective actions require costly inter-individual coordination, making continuous cost-benefit evaluation essential before engaging in cooperation. Non-human primate models can help uncover the evolutionary foundations of human cooperation and its underlying neural mechanisms. To this aim, we developed a novel paradigm to analyze the dyadic behavior of two macaques, who took turns in choosing between individual and cooperative actions to obtain variable rewards. Each monkey used a joystick to guide a cursor toward one of two targets, each indicating both the reward magnitude and the action type (i.e. solo action or joint action) required to obtain their payoff. We first observed a linear improvement in dyadic performance with the expected reward magnitude. Although macaques tended to prefer individual actions, they selected to act jointly under favorable payoff conditions, indicating that voluntary cooperation in macaques can emerge as a reward-driven process. Logistic models of their choices revealed the subjective cost monkeys assigned to cooperation, which was consistent across subjects. Nonetheless, the gain rate across different sessions increased over time, suggesting that macaques possess the cognitive ability to optimize their dyadic strategies, by estimating not only the coordination costs but also the benefits of cooperation. We observed a progressive reduction in the subjective cost assigned to joint action, which was not directly dependent on performance improvements. Our findings suggest that non-human primates can weigh the costs and benefits of cooperation, highlighting their ability to dynamically adjust social strategies based on reward contingencies. HIGHLIGHTS- Expected reward magnitude enhances cooperative performance in macaques - Monkeys evaluate the cost-benefit trade-off of cooperative actions in social contexts - In macaques, the subjective cost of cooperation decreases over time, promoting a gradual shift toward a pro-social strategy that maximizes outcomes - Cooperative behavior in macaques can emerge as a reward-driven, cost-benefit decision process - Macaques may exhibit metacognitive dynamics, using internal evaluations of expected outcomes to guide collective behavior

neuroscience↗

bioRxiv2023

A cortical mechanism linking saliency detection and motor reactivity in rhesus monkeys

Sudden and surprising sensory events trigger neural processes that swiftly adjust behavior. To study the phylogenesis and the mechanism of this phenomenon, we trained two rhesus monkeys to keep a cursor inside a visual target by exerting force on an isometric joystick. We examined the effect of surprising auditory stimuli on exerted force, scalp electroencephalographic (EEG) activity, and local field potentials (LFP) recorded from the dorso-lateral prefrontal cortex. Auditory stimuli elicited (1) a biphasic modulation of isometric force: a transient decrease followed by a corrective tonic increase, and (2) EEG and LFP deflections dominated by two large negative-positive waves (N70 and P130). The EEG potential was maximal at the scalp vertex, in all respects similar to the human vertex potential. Electrocortical potentials and force were tightly coupled: the P130 amplitude predicted the magnitude of the corrective force increase, particularly in the EEG electrodes contralateral to the limb exerting force, and in the LFP recorded from deep rather than superficial cortical layers, suggesting a direct effect of the vertex potential on the motor output determining the behavior. These results disclose a phylogenetically-preserved cortico-motor mechanism supporting adaptive behavior in response to salient sensory events.

neuroscience↗

bioRxiv2020

A distributed neocortical action map associated with reach-to-grasp

Reach-to-Grasp (RtG) is known to be dependent upon neocortical circuits and extensive research has provided insights into how selected neocortical areas contribute to control dexterous movements. Surprisingly, little infor-mation is available on the global neocortical computations underlying RtG in the mouse. Here, we characterized, employing fluorescence wide-field cal-cium imaging, the neocortex-wide dynamics from mice engaging in a RtG task. We demonstrate that, beyond canonical motor regions, several areas, such as the visual and the retrosplenial cortices, also increase their activ-ity levels during successful RtGs. Intriguingly, homologous regions across the ipsilateral hemisphere are also involved. Functional connectivity among areas increases transiently from rest to planning, and decreases during move-ment. Two anti-correlated neocortical networks emerged during movement. At variance, neural activity levels scale linearly with kinematics measures of successful RtGs in secondary motor areas. Our findings establish the coex-istence of distributed and localized neocortical dynamics for efficient control of complex movements. SIGNIFICANCE STATEMENTIn mammals, including humans, the cerebral cortex is known to be critical for the correct execution of dexterous movements. Despite the importance of the mouse for elucidating the neural circuitry for motor control, its neocortex-wide dynamics during RtG are largely unexplored. We used in-vivo fluores-cence microscopy to characterize the neural activity across the neocortex as mice performed a reach-to-grasp task. We show that for such complex movements, a large network of neocortical areas gets involved, while movement kinematics correlates with neural activity in secondary motor areas. These findings indicate the coexistence, at the mesoscale level, of distributed and localized neocortical dynamics for the execution of fine movements. This study offers a novel view on the neocortical correlates of motor control, with potential implications for neural repair.

neuroscience↗

bioRxiv2017

Rehabilitation Restores Cortical Activation Profiles And Stabilizes Synaptic Contacts After Stroke

Rehabilitation is the most effective treatment for promoting the recovery of motor deficits after stroke. Despite its importance, the processes associated with rehabilitative intervention are poorly understood. One of the most challenging experimental goals is to unambiguously link specific circuit changes induced by rehabilitation to improved behavior. Here, we investigate which facets of cortical remodeling are induced by rehabilitation by combining optical imaging and manipulation tools in a mouse model of stroke. We demonstrate the progressive restoration of cortical motor maps and of cortical activity in parallel with the reinforcement of inter-hemispheric connectivity after rehabilitation. Furthermore, we reveal that the increase in vascular density goes along with the stabilization of peri-infarct neural circuitry at synaptic level. The present work provides the first evidences that rehabilitation is sufficient to promote the combined recovery of distinct structural and functional features distinctive of healthy neuronal networks.

neuroscience↗