Figure 1. Activations (P < 10⁻⁵) of the group (n = 8) in response to the stimulation of the five locations (scheme on the left) on the middle finger (P1, green; P2, red; P3, orange) and the palm of the hand (P4, blue; P5, yellow). Activations are shown superimposed onto a surface-reconstructed left hemisphere of an individual brain that was transformed into Talairach space. Upper part: dorsal view onto the brain and the posterior bank of the central sulcus (area 3b). The hand region of the sensorimotor cortex is also given enlarged on the right (upper box). The representations can be seen to be arranged in the order P1, P2, P3 and P4 in the rostral-to-caudal direction. The representation of the proximal palm (P5) can be seen at a more medial location as compared to the set of activations due to stimulation of P1, P2, P3 and P4. Lower part: view from a lateral position onto the crown of the postcentral gyrus (area 1). Again, for visualization purposes the hand region of the sensorimotor cortex is depicted enlarged on the right (lower box). In the rostral-to-caudal direction, the representations are found mirror-reversed as compared to area 3b in the order P4, P3, P2 and P1, assuming the solitary P4 activation as the inflection point. The mirror-reversed representation pattern within areas 3b and 1 is also given schematically in the centre of the figure. CS: central sulcus. From: Evidence for a Rostral-to-Caudal Somatotopic Organization in Human Primary Somatosensory Cortex with Mirror-reversal in Areas 3b and 1 Cereb Cortex. 2003;13(9):987-993. doi:10.1093/cercor/13.9.987 Cereb Cortex | © Oxford University Press 1