Assessing the significance of focal activations using their spatial extent

摘要: Current approaches to detecting significantly activated regions of cerebral tissue use statistical parametric maps, which are thresholded render the probability one or more voxel, larger, suitably small (e. g., 0.05). We present an approximate analysis giving that a specified volume, could have occurred by chance. These results mean significant activations no longer depends on fixed (and high) threshold, but can be effected at any (lower) in terms spatial extent region. The substantial improvement sensitivity ensues is illustrated using power and simulated phantom activation study. © 1994 Wiley-Liss, Inc.