A brain circuit that suppresses distracting sensory information holds important clues about attention and other cognitive processes.
We can pick out a conversation in a loud room, amid the rise and fall of other voices or the hum of an air conditioner. We can spot a set of keys in a sea of clutter, or register a raccoon darting into the path of our onrushing car. Somehow, even with massive amounts of information flooding our senses, we’re able to focus on what’s important and act on it.
Attentional processes are the brain’s way of shining a searchlight on relevant stimuli and filtering out the rest. Neuroscientists want to determine the circuits that aim and power that searchlight. For decades, their studies have revolved around the cortex, the folded structure on the outside of the brain commonly associated with intelligence and higher-order cognition. It’s become clear that activity in the cortex boosts sensory processing to enhance features of interest.
But now, some researchers are trying a different approach, studying how the brain suppresses information rather than how it augments it. Perhaps more importantly, they’ve found that this process involves more ancient regions much deeper in the brain — regions not often considered when it comes to attention.
By doing so, scientists have also inadvertently started to take baby steps toward a better understanding of how body and mind — through automatic sensory experiences, physical movements and higher-level consciousness — are deeply and inextricably intertwined.
By Jordana Cepelewicz - Staff Writer for Quanta Magazine