Staying on task is not easy given the multiple distractions we often face.
Experts acknowledge that without the ability to focus and filter out “noise,” we could not effectively interact with our environment.
Although maintaining attention is well-established as a core brain function, until now the cellular mechanisms responsible for the effects of attention have remained a mystery.
In a new study, researchers from Dartmouth’s Geisel School of Medicine and the University of California, Davis, studied communications between connected nerve cells when subjects shifted their attention toward or away from visual stimuli that activated the recorded neurons.
Using this highly sensitive measure of attention’s influence on neuron-to-neuron communication, they were able to demonstrate that attention operates at the level of the synapse to improve sensitivity to incoming signals.
The synaptic connections (where nerve cells meet) allows sharpening of the precision of the signals, and selectively boost the transmission of attention-grabbing information while reducing the level of noisy or attention-disrupting information.
The results point to a novel mechanism by which attention shapes perception by selectively altering presynaptic weights to highlight sensory features among all the noisy sensory input.
“While our findings are consistent with other reported changes in neuronal firing rates with attention, they go far beyond such descriptions, revealing never-before tested mechanisms at the synaptic level,” said study co-author Farran Briggs, Ph.D.
In addition to expanding our understanding of the brain, this study in the future could help people with attention deficits resulting from brain injury or disease, possibly leading to improved screening and new treatments.