Tuesday 9 October 2018 16:00 – 17:00 A. Payatakes Seminar Room
“How does the brain pay attention?”
Dr. Panos Sapountzis Institute of Applied and Computational Mathematics (IACM)
Attention is a cognitive function that allows to prioritise objects or locations that are most relevant to behaviour. The ability to flexibly guide our attention to the most relevant stimuli is critical for normal behaviour and is known to be disrupted in several neuropsychiatric and neurological disorders. Thus, understanding the neural substrates of attention is of significant importance. Invasive electrophysiological studies that aim at understanding the computations that individual neurons and neuronal ensembles carry out during attention have provided most of our knowledge on the role of different brain areas in the mechanisms of attention. These studies have implicated a distributed network of brain regions including area LIP in the parietal and area FEF in the prefrontal cortex. Despite converging evidence about the instrumental role of these regions in the control of attention, the particular contribution of each area in different aspects of attention has not been fully elucidated. Moreover, it is largely unexplored how activities across distant neuronal ensembles are coordinated and how effective communication between distant areas is implemented during attention. By performing simultaneous extracellular recordings in the two areas, we found that the behavioural relevance of stimuli is more robustly encoded in the prefrontal, relative to the parietal cortex. However, information emerges simultaneously in neuronal subpopulations in the two areas. Thus, our results indicate that attentional priority signals are processed in a parallel, distributed manner within the frontoparietal network. Moreover, we found that oscillatory interactions between the two regions have distinct frequency profiles in different task epochs. These data suggest that synchrony at distinct frequency bands reflects communication principles that subserve different cognitive requirements.