Nov 2012 to Jan 2016
Institute: Sapienza University of Rome, Italy.
Thesis Title: Modulation of neural activity in frontal cortex during cooperative joint-action in non-human primates.
Supervisor: Prof. Alexandra Battaglia Mayer
Many of our actions are influenced by the interaction with other individuals. In non-human primates (NHPs) some studies have investigated the ability to interact with a partner in order to reach a common goal, looking at the behavioural aspects of these interactions. However, little is known on the capacity of NHPs to actively cooperate in a controlled experimental condition and above all on the neural substrates of such interactions. To investigate the modulation of neural activity in relation to interactive behavior, two macaque monkeys were trained to perform a cooperative joint action task. Monkeys were required to perform actions either individually or jointly with another partner, in an instructed delay task, consisting in exerting a force on an isometric joystick as to control a visual cursor on a screen. During the delay period, the animals were cued about whether they had to perform the task alone or in conjunction with their partner. Extracellular single unit activity (SUA) was recorded from the frontal cortex supposedly from the ventral premotor cortex (PMv), and simultaneously from homologous areas of two interacting monkeys by using two multiple-electrode systems. The exact location of the recording area will be confirmed after post-mortem examination.
The results suggest that when executing, the cooperative action monkeys do not rely on the same motor strategy, adopted during individual action. Specific temporal and spatial parameters indicate that the monkeys during the cooperative actions tune their own behavior to the partner's action in order to successfully achieve the common goal.
The modulation of the neural activity was mostly related to the preparation and execution of task performance, where cells started to fire during the reaction time and therefore the onset of force application and influenced by the force direction. The main result from the quantitative analyses shows that the majority of cells (33% for monkey D and 57% for monkey P) were activated not only during both the conditions in which monkeys applied the force on an isometric joystick to move the cursor on the screen but also during the observation of the cursor's movement of the interacting partner's action, probably based on a covert "mental rehearsal" mechanism. This type of activation has been observed in the absence of any visible physical movement of the partner, in a context where to the animals it was only visible moving cursors on a screen, representing the result of force application.
Aug 2006 to June 2012
Institute: Centre for Converging Technologies, University of Rajasthan, Jaipur, India.
Thesis Title: fMRI Studies in Cognition
Supervisor: Prof. Shobini L. Rao