Speech Motor Learning and Retention (Aim 1)

The overall goal of this research is to test a new model of speech motor learning, whose central hypothesis is that learning and retention are associated with plasticity not only in motor areas of the brain but in auditory and somatosensory regions as well. The strategy for the proposed research is to identify individual brain areas that contribute causally to retention by disrupting their activity with transcranial magnetic stimulation (TMS). Investigators will also use functional magnetic resonance imaging (fMRI) which will enable identification of circuit-level activity which predicts either learning or retention of new movements, and hence test the specific contributions of candidate sensory and motor zones. In other studies, investigators will record sensory and motor evoked potentials over the course of learning to determine the temporal order in which individual sensory and cortical motor regions contribute. The goal here is to identify brain areas in which learning-related plasticity occurs first and which among these areas predict subsequent learning.

The focus of this registration is Aim 1. The work in Specific Aim 1 involves tests of speech motor memory retention following disruption of left hemisphere brain activity in either auditory, somatosensory or motor cortex or to a control site (hand area motor cortex right hemisphere). Continuous theta-burst stimulation (cTBS) is delivered following adaptation to altered auditory feedback to assess its effects on the retention of new learning. In the adaptation task, participants read Harvard Sentences aloud, which are presented on a computer monitor. Vocal output is altered in real-time and played back to participants through headphones. Tests of retention are conducted 24 hours later. The Speech Motor Learning and Retention Master Protocol has uniqueID 2000037622.