During the whole duration of this project we have worked on three research lines.
First, we have studied, in over 50 healthy subjects, how the brain changes in preparation for movements by applying transcranial magnetic stimuli at different times relative to the future movements to be performed. This research shows that brain responses to external stimuli during movement preparation are suppressed. It also suggests that this change in brain responses is present in all types of planned movements regardless of what triggers them. We think that this indicates that brain responses to external stimuli may reflect the dynamics of the neural populations that are evolving towards generating the desired movements at the desired time. This interpretation contradicts previous views, which proposed that the brain responses to stimuli reflected proactive inhibitory mechanisms of the motor cortex. Additionally, by carrying out this research we have found a very interesting link between self-initiated and cue-driven movements: they seem to share similar triggering mechanisms, which also means that self-initiated movements depend on triggers that can be external or internal. Overall, this research has been presented in 3 international conferences and it is expected to result in 2 articles in high impact journals. Results of this research are also expected to have impact on researchers trying to identify the neurophysiological mechanisms that lead to certain types of movements disorders (like bradykinesia in Parkinson’s Disease or tics in Tourette’s syndrome).
Second, in over 100 experiments with healthy participants, we have studied new protocols that allow us to induce brain plastic changes by delivering electrical nerve stimuli or magnetic brain stimuli that interact with the brain neural activity. The main characteristic of this research line is that we have worked on the concept of brain state-dependent brain stimulation to propose new alternatives to boost the selectivity and specificity of the neuroplastic changes induced with the stimulation protocols. Brain state-dependent brain stimulation and our work developed in this line during this project are meant to allow us in the future to achieve new brain stimulation strategies that can be used to boost the specificity and functional relevance of the plastic changes induced in the brain. The impact of this research is associated with the fact that the obtained new knowledge is expected to allow us to propose more effective neuromodulation treatments for neurorehabilitation. This research has been presented in 2 international conferences and we plan to publish the main findings in 2 articles submitted to journals of high impact.
Finally, we have initiated a very promising research line aimed to look at strategies to extract brain-relevant neural information from the muscles. The hypothesis that we have been able to demonstrate already is the fact that surface muscle recordings can be used to extract activity of spinal motor neurones that allow us to track ongoing brain oscillatory activity regardless of whether external stimuli are being applied to the brain. We have also proven that the neural activity extracted from the muscles has a very tight temporal association with ongoing brain rhythmic activity. The main impact here is expected to be the possibility of developing new ways of tracking and stimulating the brain during movement processing.
