Search bioRxivSearch

Biology subjects

Fabbrini, F.

Publications and source records attributed to Fabbrini, F..

2 recordsLinked to original sources

Neuronal dynamics of signal selective motor plan cancellation in the macaque dorsal premotor cortex

Primates adopt various strategies to interact with the environment. Yet, no study has examined the effects of behavioral strategies with regard to how movement inhibition is implemented at the neuronal level. We modified a classical approach to study movement control (stop-task) by adding an extra signal - termed the Ignore signal - which influenced movement inhibition only under a specific strategy. We simultaneously recorded multisite neuronal activity from the dorsal premotor (PMd) cortex of macaque monkeys during a task and applied a state-space approach. As a result, we found that movement generation is characterized by neuronal dynamics that evolve between subspaces. When the movement is halted, this evolution is arrested and inverted. Conversely, when the Ignore signal is presented, inversion of the evolution is observed briefly and only when a specific behavioral strategy is adopted. Moreover, neuronal signatures during the inhibitory process were predictive of how PMd processes inhibitory signals, allowing the classification of the resulting behavioral strategy. Our data corroborate the PMd as a critical node in movement inhibition.

neuroscience

Neuronal activity in the premotor cortex of monkeys reflects both cue salience and motivation for action generation and inhibition

Animals adopt different strategies, promoting certain actions and withholding inconvenient ones, to achieve their goals. The motivation to obtain them is the main drive that determines the behavioural performance. While much work has focused on understanding how motor cortices control actions, their role on motivated behaviours remains unclear. We recorded from dorsal premotor cortex (PMd) of monkeys performing a modified version of the stop-signal task, in which the motivation to perform/withhold an action was manipulated by presenting cues that informed on the probability to obtain different amounts of reward in relation to the motor outcome. According to the motivational context, animals performance adapted to maximize reward. Neuronal activity displayed a cue salience related modulation at trial start and, while the behavioural response approached, reflected more the motivation to start/cancel the action. These findings reveal multiple representations of motivation-related signals in PMd, highlighting its involvement in the control of finalized actions.\n\nSIGNIFICATIVE STATEMENTThe motivation to obtain rewards drives how animals act over their environment. To explore the involvement of motor cortices in motivated behaviours, we recorded high-resolution neuronal activity in the premotor cortex of monkeys performing a task that manipulated the motivation to generate/withhold a movement through different cued reward probabilities. Our results show the presence of neuronal signals dynamically reflecting a cue related activity, in the time immediately following its presentation, and a motivation related activity in performing (or cancelling) a motor program, while the behavioural response approached. The encoding of multiple reward-related signals in motor regions, leads to consider an important role of premotor areas in the reward circuitry.

neuroscience