ClusterTDP: an SPM extension providing True Discovery Proportions (TDPs) for cluster-level analyses

In a standard functional MRI data analysis pipeline the final step is often a correction of multiple comparisons. This step determines which regions of the brain show significant activation. The SPM software package provides users with extensive information on brain activity across different levels of analysis: set (whole brain), cluster (random-field based clusters), and voxelwise statistics. Interpretation of results differs across these levels, as for example cluster level statistics only tell researchers that there is activity in a cluster, but not where in that cluster activity is located. In other words, cluster-level statistics are about the extent of a cluster, but provide no information of the activity within a cluster. We recently developed a cluster-level compatible measure for the amount of signal within a cluster: clusterTDP. This measure estimates the amount of significantly activated voxels within a cluster, thus providing the researcher with valuable information on activity within the cluster. Here we introduce the clusterTDP SPM extension: a SPM compatible extension that provides True Discovery Proportions (TDP) for cluster-level analyses. The extension seamlessly integrates in the SPM pipeline making running the analysis and interpreting results easy. In this session we will show how to install and use the SPM extension, as well as how to interpret results.