Dynamics of brain networks: the connectivity modulated by external motors stimuli

BOCACCIO H.; VILLARREAL M.

Buenos Aires

Congreso; 2nd Federation of Latin-American and Caribbean Neuroscience Societies (FALAN) Congress; 2016

Sociedad Argentina de Investigación en Neurociencias (SAN)

In the last decades, the fMRI technique has influenced on many publications related to the study of the cerebral dynamics. Among them, there are studies about: 1) brain activity enhancement due to external stimuli, that allow to relate a specific topography to a determined functionality; 2) spontaneous cortical activity during resting state, which is organized in non trivial spatio-temporal networks.The presence of external stimulation modulates the brain activity only on specific areas. This implies that stimuli could modify the brain coherence patterns associated with spontaneous fluctuations. The aim of this work is to analyze the possible changes on brain connectivity resting state patterns in response to a external stimulus. For this purpose we study the dynamics of correlations between the average signals of AAL regions, while healthy subjects perform a simple motor task block-design and during resting state. We applied support vector machine methods to train a classifier that identify configurations of brain coherence on task and rest. We found that correlations shows significant differences between task conditions, and between motor task and resting state, in different brain regions. These results suggest that the correlation dynamics changes the pattern of brain networks when an external stimulus is present. In particultar, the modulation due to motor task yield a disruption on the coherence of the motor network.