Towards Development of a Circuit Based Treatment for Impaired Memory: A Multidisciplinary Approach

The previous decade saw progress in our understanding of fundamental neural systems of the brain, particularly those sub-serving memory. For example, it is now recognized that individual power and peak frequency attributes of alpha band rhythms predict performance on a working memory task. Additionally, investigators using transcranial magnetic stimulation (TMS), a safe and non-invasive means of stimulating the awake and alert human brain, have shown TMS can mimic long-term potentiation (LTP), widely considered the neurophysiologic substrate of memory. Based on this earlier work, we designed a combined TMS-EEG study of the effects of 10Hz rTMS on psychomotor processing speed, an index of neural efficiency, on a well validated short-term verbal recognition memory task, the Sternberg. We predicted first, that compared with sham 10Hz repetitive transcranial magnetic stimulation (rTMS) would significantly reduce psychomotor processing speed indexed as reaction time (RT). Second, we predicted that improvement in RT would be associated with a 10Hz rTMS induced increase in pre-task alpha power and pre-task alpha band phase synchrony.