My research is organized around three main themes.
Traditionally, this laboratory has been interested in elucidating the brain mechanisms underlying our ability to select sensory stimuli in the environment and respond to them (selective attention). We use psychophysics and fMRI to map and describe physiological signals related to selective attention. We have identified different control networks for goal-driven vs. stimulus-driven attention, and showed that these networks modulate occipital visual cortex anticipating what the subject expect to see. Currently, we are investigating how attention interact with other cognitive functions including memory, reward, and theory of mind.
An important extension of this work is to understand the more general problem of large-scale neural communication. How neuronal groups that are separated in the brain communicate either spontaneously or during active behavior? What neuronal codes are used for communication? How communication measured with fMRI at slow temporal scales relates to electrophysiological signals measured at faster temporal scales? To this end, I am coordinating a large multi-center study (BrainSynch: www.brainsynch.org) housed in Europe and that involves eight different countries (USA, Italy, UK, Belgium, Netherlands, France, Germany, Spain, Czeck Republic).
This project involves neuroimaging (fMRI), neurophysiology (MEG, iEGG, ECoG, single unit), stimulation (TMS, microstimulation), and computational methods in both healthy subjects and patients with neurological disorders that impair large-scale communication, and non-human primates.
Finally, a more clinical line of research focuses on the neurological mechanisms of recovery after brain injury (stroke and traumatic brain injury). Subjects with brain injuries are studied with a combination of clinical, behavioral, and brain scan tests that track their recovery over time. The results of such tests are then correlated with final outcome. We have shown that structural lesions in the brain are associated with widespread physiological impairments both in task-driven and spontaneous activity. Notably, an imbalance in task activation and communication between the two sides of the brain in motor and attention networks correlates, even when these regions are structurally intact, respectively with the degree of hemiparesis and spatial neglect. We hope to identify mechanisms of recovery at the systems level that could potentially be used as targets for novel interventions, and to develop prognostic indexes/models of functional recovery for outcome prediction.