Anodal Transcranial Direct Current Stimulation Over Prefrontal Cortex Slows Sequence Learning in Older Adults.

Aging is associated with declines in sensorimotor function. Several studies have demonstrated that transcranial direct current stimulation (tDCS), a form of non-invasive brain stimulation, can be combined with training to mitigate age-related cognitive and motor declines. However, in some cases, the application of tDCS disrupts performance and learning.

Regular participation in leisure time activities and high cardiovascular fitness improve motor sequence learning in older adults.

Introduction: Older adults show higher interindividual performance variability during the learning of new motor sequences than younger adults. It is largely unknown what factors contribute to this variability. This study aimed to, first, characterize age differences in motor sequence learning and, second, examine influencing factors for interindividual performance differences.

Multi-session Transcranial Direct Current Stimulation Over Primary Motor Cortex Facilitates Sequence Learning, Chunking, and One Year Retention.

Transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) can facilitate motor learning, but it has not been established how stimulation to other brain regions impacts online and offline motor sequence learning, as well as long-term retention. Here, we completed three experiments comparing the effects of tDCS and sham stimulation to the prefrontal cortex (PFC), M1, and the supplementary motor area complex to understand the contributions of these brain regions to motor sequence learning. In Experiment 1, we found that both left and right PFC tDCS groups displayed a slowing in learning in both reaction time and number of chunks, whereas stimulation over M1 improved both metrics over the course of three sessions.

Training Motor Sequences: Effects of Speed and Accuracy Instructions.

Participants practiced a fixed 3- and a fixed 6-key press sequence for 144 times each. In the speed group, they were instructed to execute their sequences fast without bothering much about errors while the accurate group was instructed to be careful and prevent errors. In the test phase, participants executed series of 3 and 6 responses (a) when all element-specific stimuli were displayed in the familiar order, (b) in response to just the familiar first stimulus, and (c) by responding to random stimuli.