Comparison of Sensory Observation and Somatosensory Stimulation in Mirror Neurons and the Sensorimotor Network: A Task-Based fMRI Study

Abstract

ObjectiveThis study aimed to investigate brain plasticity by somatosensory stimulation (SS) and sensory observation (SO) based on mirror neuron and embodied cognition theory. Action observation therapy has been widely adopted for motor function improvement in post-stroke patients. However, it is uncertain whether the SO approach can also contribute to the recovery of sensorimotor function after stroke. In this study, we explored the therapeutic potential of SO for sensorimotor dysfunction and provided new evidence for neurorehabilitation.MethodsTwenty-six healthy right-handed adults (12 men and 14 women), aged 18–27 (mean, 22.12; SD, 2.12) years were included. All subjects were evaluated with task-based functional magnetic resonance imaging (fMRI) to discover the characteristics and differences in brain activation between SO and SS. We adopted a block design with two conditions during fMRI scanning: observing a sensory video of brushing (task condition A, defined as SO) and brushing subjects' right forearms while they watched a nonsense string (task condition B, defined as SS). One-sample t-tests were performed to identify brain regions and voxels activated for each task condition. A paired-sample t-test and conjunction analysis were performed to explore the differences and similarities between SO and SS.ResultsThe task-based fMRI showed that the bilateral postcentral gyrus, left precentral gyrus, bilateral middle temporal gyrus, right supramarginal gyrus, and left supplementary motor area were significantly activated during SO or SS. In addition to these brain regions, SO could also activate areas containing mirror neurons, like the left inferior parietal gyrus.ConclusionSO could activate mirror neurons and sensorimotor network-related brain regions in healthy subjects like SS. Therefore, SO may be a promising novel therapeutic approach for sensorimotor dysfunction recovery in post-stroke patients.

Effects of integrated action and sensory observation therapy based on mirror neuron and embodied cognition theory on upper limb sensorimotor function in chronic stroke: a study protocol for a randomised controlled trial

“…Our previous study found that the precentral gyrus, supplementary motor area and postcentral gyrus could be activated in somatosensory stimulation (SS) and sensory observation (SO) in healthy subjects. 58 These brain regions are responsible for movement execution, movement preparation and sensory integration. 59 60 Evidence from animal and clinical studies suggests that the activation of these brain regions contributes to functional reorganisation after stroke.…”

“…65 In addition, SS showed increased activation of the thalamus and insula. 58 The thalamus and insula are considered integration centres that integrate diverse information, such as motor, sensory, emotional and social information, that is processed throughout the cerebral cortex. [66][67][68] Furthermore, the thalamus is also associated with prognosis and recovery after stroke.…”

“…Evidence from animal and clinical studies suggests that the activation of these brain regions contributes to functional reorganisation after stroke 61 62. Moreover, SO activates the inferior parietal gyrus and superior parietal gyrus, which are important components of the posterior parietal cortex 58 63 64. One study in the macaque monkey shows that the posterior parietal cortex is involved in sensorimotor transformation 65.…”

“…One study in the macaque monkey shows that the posterior parietal cortex is involved in sensorimotor transformation 65. In addition, SS showed increased activation of the thalamus and insula 58. The thalamus and insula are considered integration centres that integrate diverse information, such as motor, sensory, emotional and social information, that is processed throughout the cerebral cortex 66–68.…”

Acupuncture Alters Brain’s Dynamic Functional Network Connectivity in Stroke Patients with Motor Dysfunction: A Randomised Controlled Neuroimaging Trial

“…As a noninvasive neuroimaging technology, functional magnetic resonance imaging (fMRI) lays the foundation for real-time measurement of whole-brain activity and helps advance the understanding of neuroplasticity modulated by acupuncture [16,17]. Neuroimaging evidence has demonstrated the facilitating effect of acupuncture in the regulation of brain functional reorganization, comprising activation of motor-related cortical areas [18][19][20], increasing motorcognition connectivity and decreasing compensation of contralesional motor cortex, and modulating effective connectivity of resting-state networks in patients with poststroke hemiplegia [21,22].…”