Brain halves increase communication to compensate for aging, study finds -- ScienceDaily"This study provides an explicit test of some controversial ideas about how the brain reorganizes as we age," said lead author Simon Davis, PhD. "These results suggest that the aging brain maintains healthy cognitive function by increasing bilateral communication." Simon Davis and colleagues used a brain stimulation technique known as transcranial magnetic stimulation (TMS) to modulate brain activity of healthy older adults while they performed a memory task. When researchers applied TMS at a frequency that depressed activity in one memory region in the left hemisphere, communication increased with the same region in the right hemisphere, suggesting the right hemisphere was compensating to help with the task. In contrast, when the same prefrontal site was excited, communication was increased only in the local network of regions in the left hemisphere. This suggested that communication between the hemispheres is a deliberate process that occurs on an "as needed" basis.