Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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Introduction: Recent studies have demonstrated that responses to single mental events and brief motor tasks can be detected using fMRI. Previous results indicate that the response after a single-trial task is sustained for more than 5 s. To achieve more spatial coverage, we reduced the sampling of BOLD signal to one instant of time per paradigm condition. Methods: Ten healthy volunteers were studied with a 1.5-T Siemens Vision system. The paradigm consisted of three phases (preparation, motor, rest) beginning with an auditory cue. A gradient-echo echo-planar sequence (TE 70 ms, TR 10920 ms, slice thickness 3 mm, matrix 64x64, FoV 192 mm, 64 transaxial slices in cranio-caudal order) was used for functional imaging. Pixelwise paired t-tests between preparation and baseline as well as motor and baseline conditions were performed after motion correction. Results and Conclusions: Statistically significant activations were detected with spatial coverage extending from the most cranial cerebral areas down to the cerebellum. We have demonstrated that it is feasible to map BOLD responses from the whole brain during a single-trial paradigm. The test paradigm used resembles those traditionally used in evoked potential studies. This allows comparison of electrophysiological data and fMRI using exactly the same experimental setup.

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Poster Number PAkorvenoja0652
Keywords: motor, event-related, magnetic, resonance, imaging