Differential Contribution of Bilateral Supplementary Motor Area to the Effective Connectivity Networks Induced by Task Conditions Using Dynamic Causal Modeling

Abstract

Functional imaging studies have indicated hemispheric asymmetry of activation in bilateral supplementary motor area (SMA) during unimanual motor tasks. However, the hemispherically special roles of bilateral SMAs on primary motor cortex (M1) in the effective connectivity networks (ECN) during lateralized tasks remain unclear. Aiming to study the differential contribution of bilateral SMAs during the motor execution and motor imagery tasks, and the hemispherically asymmetric patterns of ECN among regions involved, the present study used dynamic causal modeling to analyze the functional magnetic resonance imaging data of the unimanual motor execution/imagery tasks in 12 right-handed subjects. Our results demonstrated that distributions of network parameters underlying motor execution and motor imagery were significantly different. The variation was mainly induced by task condition modulations of intrinsic coupling. Particularly, regardless of the performing hand, the task input modulations of intrinsic coupling from the contralateral SMA to contralateral M1 were positive during motor execution, while varied to be negative during motor imagery. The results suggested that the inhibitive modulation suppressed the overt movement during motor imagery. In addition, the left SMA also helped accomplishing left hand tasks through task input modulation of left SMA/right SMA connection, implying that hemispheric recruitment occurred when performing nondominant hand tasks. The results specified differential and altered contributions of bilateral SMAs to the ECN during unimanual motor execution and motor imagery, and highlighted the contributions induced by the task input of motor execution/imagery.

Neural predictors of motor control and impact of visuo‐proprioceptive information in youth

“…Furthermore, GM analyses showed that a larger cortical thickness of M1 was related to higher performance accuracy (lower phase error) in all sensory conditions, with the strongest effect obtained in visual tracking. These findings are consistent with previous literature, showing that M1 is functionally associated with movement planning and execution [Gao et al, ; Gentilucci et al, ; Immisch et al, ; Jancke et al, ; Swinnen and Wenderoth, ; Toyokura et al, ], and larger thickness of motor regions relates to improved performance on motor tasks [Anderson et al, ]. Our results add to this existing knowledge by showing that the strength of the association between M1 thickness and tracking accuracy of passive movements depends on the available sensory information.…”

Dynamic Causal Modeling on the Identification of Interacting Networks in the Brain: A Systematic Review

“…2. 2) FC-PC: This is the most frequent effective connectivity category in the literatures, with 80 publications [4], [8][9][10][11][12][13][14][15][16], [18][19][20], [21][22][23][24], [27][28][29], [31][32], [34], [36][37][38][39][40][41][42][43], [46], [55][56][57] , [62 ] , [67 ] , [71 -74 ] , [76][77], [79], [81][82][83], , [107][108][109][110][111][112][113][114][115]…”

An fMRI-compatible force measurement system for the evaluation of the neural correlates of step initiation

“…In fact, the bilateral SMA are reciprocally connected, projecting to both ipsilateral and contralateral primary motor cortex 22 23 . Both EEG and fMRI studies using connectivity analysis such as dynamic causal modeling (DCM) and effective connectivity networks (ECN) have shown bilateral interactions between SMA 24 25 26 during unilateral manual tasks. These facts may explain the functional evidence of contralateral 24 27 28 and bilateral 29 30 SMA activation during simple unilateral hand and finger movements.…”