The probability map of the lesions resulting from the group average of the four patients who presented with pure speech apraxia. The peak of the lesion overlap is located in the precentral gyrus of the insula (gyrus brevis III). There was also minor involvement of the most inferior part of the central sulcus and of the subcentral opercular cortex. Note that there was no involvement of Broca’s region on the inferior frontal gyrus, namely the pars opercularis (area 44) and the pars triangularis (area 45). The brain sections are presented in the Y (coronal) and X (sagittal) coordinates in the MNI standard stereotaxic brain space (Petrides 2019).