Frontiers in Human Neuroscience (May 2014)
BEYOND THE ‘PAIN MATRIX’, INTER-RUN SYNCHRONIZATION DURING MECHANICAL NOCICEPTIVE STIMULATION
Abstract
Pain is a complex experience that emerges from the activity multiple brain areas, some of which are inconsistently detected using traditional fMRI analysis. One hypothesis is that the traditional analysis of pain-related response, by relying on the correlation of a predictor convolved with the canonical hemodynamic response function (HRF)- the general linear model (GLM)- may under-detect the activity of those areas involved in stimulus processing that do not present a canonical HRF. In this study, we employed an innovative data-driven processing approach- an inter-run synchronization analysis- that has the advantage of not establishing any pre-determined predictor definition. With this method we were able to evidence the involvement of several brain regions that are not usually found when using predictor-based analysis. These areas are synchronized during painful stimulation and are characterized by a BOLD response that differs from the canonical HRF. This finding opens to new approaches in the study of pain imaging.
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