Ponente invitad@: Alex Sel. Investigating the neural dynamics of the human action selection network across the adult lifespan

In situations where we are required to stop or suppress ongoing actions—for example, halting while crossing the road when an errant cyclist suddenly veers into our path—the ability to rapidly interrupt behaviour determines whether we respond safely and effectively to unexpected environmental demands. This capacity, commonly referred to as response inhibition, is essential for successful interaction with ever-changing environments. Response inhibition is exerted through the action selection brain circuit, known as the cortico-basal ganglia-thalamocortical network. Integrity within this network is associated with better motor and inhibitory abilities; thus, for example, healthy ageing is associated with altered connectivity in cortico-cortical and cortico-subcortical pathways within the action selection network, accompanied by impaired response inhibition. In this talk, I will present a series of studies that have used novel forms of non-invasive brain stimulation alone, and in combination with neuroimaging techniques, to directly examine the causal impact of altered connectivity in the action selection network on response inhibition across the adult lifespan. Specifically, these studies show that it is possible to increase interregional coupling between the regions of the action selection network by evoking synchronous pre- and postsynaptic activity in the pathways connecting such regions. The modulation of the neural pathways results in increases in functional connectivity and frequency communication within the action selection network in young and older adults, as well as improved inhibitory performance. Altogether, these investigations demonstrate that neural communication in the action selection network can be selectively manipulated to improve response inhibition in older adults, highlighting the translational potential of non-invasive brain stimulation for ameliorating age-related decline in cognitive and motor control