Procedures for image analysis. Raw data from MPRAGE sequences (a, c) were reoriented to place the line of the anterior-posterior commissure (AC open arrowheads; PC arrowheads) on both the horizontal (b) and the mid-sagittal (d) planes. The limen insulae was pointed to on the most anterior coronal slice on which the temporal stem was recognized (green cross in e). The accuracy of the point placement was confirmed on a sagittal slice (green cross in f). The target (red cross in g) was pointed to the midpoint between the hippocampal sulcus (black cross in the medial in g) and the innominate sulcus (black cross in the lateral in g) on the coronal slice through the posterior edge of the amygdala. Its location was also confirmed on an axial slice (red cross in h).