Figure 2. Relative levels of cortical lamination in the PFC and insula in the macaque. A, Ventral view. B, Sagittal view from the midline. C, Lateral view, with lateral fissure “opened” for (C') view of insula. Image adapted from Carmichael and Price (1994) and Mesulam and Mufson, 1982. The key illustrates the range of cortical differentiation; shades of blue indicate agranular cortex, shades of green indicate dysgranular cortex, and shades of red indicate granular cortex. The darker the shade within each granularity grouping indicates increased development of Layer IV, Layer II, and/or Layer V of cortex. Insets are from cresyl violet-stained sections that give examples of laminar regions in agranular, dysgranular and granular cortices. Scale bar: 500 μm. 6, area 6 (premotor/supplementary motor area); 8Ad, dorsal area 8A; 8Av, ventral area 8A; 8B, area 8B; 9d, dorsal area 9; 9m, medial area 9; 9/46d, dorsal area 9/46; 9/46v, ventral area 9/46; 10m, medial area 10; 10o, orbital area 10; 11l, lateral area 11; 11m, medial area 11; 12l, lateral area 12; 12m, medial area 12; 12o, orbital area 12; 12r, rostral area 12; 13a, area 13a; 13b, area 13b; 13l, lateral area 13; 13m, medial area 13; 14c, caudal area 14; 14r, rostral area 14; 24a, area 24a; 24b, area 24b; 24c, area 24c; 25c, caudal area 25; 25r, rostral area 25; 32c, caudal area 32; 32r, rostral area 32, 45, area 45; 46, area 46; cc, corpus callosum; G, gustatory cortex; Iai, intermediate agranular insula area; Ial, lateral agranular insula area; Iam, medial agranular insula area; Iapl, posterolateral agranular insula area; Iapm, posteromedial agranular insula area; Id, dysgranular insula; Ig, granular insula; ob, olfactory bulb; oc, optic chiasm; PrCO, precentral opercular area.