Time-Resolved fMRI of Activation Patterns in M1 and SMA During Complex Voluntary Movement

Abstract

The aim of this study was to use time-resolved functional magnetic resonance imaging (fMRI) to investigate temporal differences in the activation of the supplementary motor area (SMA) and the primary motor cortex (M1). We report data from eight human volunteers who underwent fMRI examinations in a 1.5T Philips Gyroscan ACS-NT MRI scanner. While wearing a contact glove, subjects executed a complex automated sequence of finger movements either spontaneously or in response to external auditory cues. Based on the result of a functional scout scan, a single slice that included the M1 and the SMA was selected for image acquisition (echo planar imaging, repetition time 100 ms, echo time 50 ms, 64 x 64 matrix, 1,000 images). Data were analyzed with a shifting cross-correlation approach using the STIMULATE program and in-house programs written in Interactive Data Language (IDL(TM)). Time-course data were generated for regions of interest in the M1 as well as in the rostral and caudal SMA. Mean time between onset of the finger movement sequence and half-maximum of the signal change in M1 was 3.6 s for the externally cued execution (SD 0.5) and 3.5 s for the spontaneous execution (SD 0.6). Activation in the rostral section of the SMA occurred 0.7 s earlier than it did in the M1 during the externally cued execution and 2.0 s earlier during the spontaneous execution, a difference significant at the P < 0.01 level. Our results indicate that rostral SMA activation precedes M1 activation by varying time intervals in the sub-second range that are determined by the mode of movement initialization. By applying a paradigm that exerts a differential influence on temporal activation, we could ensure that the observed timing differences were not the result of differences in hemodynamic response function.

Towards a functional topography of sensory gating areas: Invasive P50 recording and electrical stimulation mapping in epilepsy surgery candidates

“…With respect to volition, the SSMA, as a premotor region, is known to be involved in self-initiated and externally cued movement (Cunnington, 2002;Toma, 2003). Its activity precedes that of the primary motor cortex in intentional movement (Weilke, 2001). In most of these studies that demonstrate the involvement of the SSMA in volition, auditory cues are chosen for external triggering of movements (e.g., Cunnington, 2002;Toma, 2003;Kurata, 2000).…”

Spatio-temporal information analysis of event-related BOLD responses

“…We find that in most cases there is a peak of MI value around a particular latency between the two signals, suggesting that in terms of information content, the signal in one ROI precedes, or lags after, that of the other ROI with that latency. Here we show, for example, that SMA preferably precedes left PM by approximately 1s, pre SMA precedes left PPC by 1.5s, left PPC follows right PPC by about 0.5-1s, and that the signals of SMA and pre SMA are most informative about each other's activity with zero delay [Ikeda et al, 1992;Kansaku et al, 1998;Menon et al, 1998;Weilke et al, 2001;Sun et al, 2005].…”

“…While spatial localization of task-related BOLD responses has been extensively explored for many task conditions, few studies only have addressed temporal aspects of neuronal circuitry engaged in task-performance. Despite the challenges in mapping of BOLD responses to underlying neural responses, several attempts have been made to address temporal aspects of BOLD responses, most within the framework of the GLM analysis [Menon et al, 1998;Menon and Kim, 1999;Miezin et al, 2000;Weilke et al, 2001;Formisano et al, 2002;Henson et al, 2002;Hernandez et al, 2002;Liao et al, 2002;Bellgowan et al, 2003;Mohamed et al, 2003;Saad et al, 2003;Sun et al, 2005]; see ] for review). Some studies have used nonlinear approaches for fitting the HRF [Calhoun et al, 2000;Richter et al, 2000].…”

Bilateral supplementary motor area syndrome causing akinetic mutism following parasagittal meningioma resection

“…The dominant SMA-proper is also connected to the inferior frontal gyrus by the frontal aslant tract and plays a role in the production of speech [13,18,[34][35][36]. On the afferent side, the SMA-proper receives input from the globus pallidus, thalamus, cerebellar dentate nucleus, and the primary sensory cortex [1,4,[15][16][17]20,[33][34][35][37][38][39][40][41][42][43][44].…”

“…It is involved in conditional behavior learning and the production of speech [1,3,[6][7][8][9][10][11][12][13][14][15][16][17]. Recent studies suggest an even wider area, the supplementary motor complex, which includes the SMA, the pre-SMA, and supplementary eye fields, serves as a crucial link between cognitive function and elaborative action [1,10,11,[18][19][20].…”