Importância da rede cortical motora na percepção de movimentos humanos

Tipo
Tese
Data
2016-12-15
Autores
Lapenta, Olivia Morgan
Orientador
Boggio, Paulo Sérgio
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Macedo, Elizeu Coutinho de
Brunoni, Andre Russowsky
Corrêa, Sônia Cavalcanti
Simis, Marcel
Programa
Distúrbios do Desenvolvimento
Resumo
Action recognition is fundamental to comprehend other’s attitudes and it has been suggested that this process is mapped in an active fashion by the transposition of the observed action to our own motor repertoire. This process is mediated by the mirror neuron system, a fronto-parietal circuitry, and also activates the primary motor cortex (M1). Movement perception and the activation of this circuitry occurs even in the absence of pictorial information, for example when presenting stimuli built with point-lights (PL) distributed in the main joints. Studies evaluate the mirror neuron system activity and the enrolment of the motor network manly using transcranial magnetic stimulation (TMS), by means of motor evoked potential (MEP) and electroencephalography, by means of Mu rhythm oscillations. We elaborated two studies aiming to evaluate: 1- MEP differences TMS-induced during observation of biological and non-biological movements and the absence of movement in PL display and further if the modulation of M1 or premotor cortex (PMC) using transcranial direct current stimulation (tDCS) alters cortical excitability and the perception of the observed movements; 2-differences in MEPs and Mu rhythm measures during observation of goal-directed actions with precision or power grasp and, further, if TMS and EEG measures correlate. In study 1 we found greater MEPs during the presentation of biological and non-biological motion when compared to a static person in PL. Furthermore, anodal tDCS over M1 reduced the corticospinal excitability and the performance in the action identification task; we didn’t found effects of tDCS applied over PMC. Our findings show motor network recruitment during movement observation and, further, that M1 has an important role for action identification. In study 2 we identified differences in Mu desynchronization and in MEP amplitudes according to the stage of the observed actions. We found greater activation of the motor network during the course of action when compared to its final stage. Such process allows for anticipating the movement end and, therefore, the identification of the action goal. Moreover, only MEP measures, but not of Mu rhythm were modulated by the muscle involved in the task, differing in accordance to grasp type. Correlations between Mu and MEPs measures were not found, suggesting that albeit both represent a valid index of neural mirroring, those measures reflect different activities underlying this circuitry.
Descrição
Palavras-chave
ressonância motora , neurônios-espelho , observação de ação , neuromodulação , excitabilidade cortical
Citação
LAPENTA, Olivia Morgan. Importância da rede cortical motora na percepção de movimentos humanos. 2016. 116 f. Tese( Distúrbios do Desenvolvimento) - Universidade Presbiteriana Mackenzie, São Paulo.