Neural Mechanisms of Selective Attention

Our senses convey rich and detailed information about the external world, but we can selectively attend to some details while ignoring others. This capacity for selective attention is critical for survival and essential for complex tasks. Problems with controlling and directing attention, such as attention deficit hyperactivity disorder (ADHD), can impair the ability of individuals to function normally. Attentional mechanisms have been studied at several different recording scales – from single neurons in monkeys to diffuse population measures such as electroencephalography (EEG) in humans. However, the relationship between signals recorded from such different scales is poorly understood.

The long-term goal of this research is to elucidate the mechanisms of attention by linking the neural recordings obtained from these vastly different scales. In particular, we focus on particular oscillations in the brain, such as the alpha (~10 Hz) or gamma rhythms (30-80 Hz), which are modulated by the attentional load, and can readily be recorded from both micro and macroelectrodes. Several types of recording scales are investigated. In humans, we record using EEG electrodes and also collaborate with neurosurgeons who work with epileptic patients and record from electrodes placed directly on the brain (called  electrocorticogram or ECoG). In non-human primates (NHPs) trained to perform an attention task, we record from microelectrodes as well as ECoG and EEG electrodes. Apart from studying attention, this approach allows us to understand the neural basis of EEG, which has direct applications in the diagnosis of brain disorders and in brain machine interfaces. We also develop signal-processing tools to study brain signals, which are highly non-stationary and often require special analysis techniques.

PI : Dr.Supratim Ray (Webpage)