Figure 1.

Select stages of flattening the frontal and parietal cortex from the left hemisphere of a macaque monkey brain. A, Medial and dorsolateral views of the left hemisphere. B, The medial and lateral banks of the intraparietal sulcus are partially separated from one another. The rostral and caudal banks of the inferior arcuate sulcus are also partially separated from one another. The upper bank and fundus of the lateral sulcus are separated from the lower bank. C, The occipital lobe and most of the temporal lobe are removed. D, The banks of the intraparietal sulcus and the arcuate sulcus are further separated. The rostral and caudal banks of the central sulcus are partially separated. The medial wall and the insular cortex are unfolded. Most of the prefrontal cortex is removed and the remaining banks of the principal sulcus are separated. E, The cortex is blocked into two pieces, which are flattened between two glass slides. The top block includes most of the medial wall. Scale bar applies to all panels. Abbreviations are described in Table 1.