Table 1. Anatomical descriptions of landmark sulci.
| Trait code | Trait full name | Anatomical description of sulcus |
|---|---|---|
| arsp | Arcuate rectus spur | Possible posterior spur off of junction of arcuate rectus inferior and superior projections. |
| cs | Central sulcus | Major fold extending interiorly from midline of brain separating frontal and parietal brain lobes and curling rostrally or branching before reaching the lateral sulcus. |
| iar | Inferior arcuate rectus | Inferior branch of the arcuate rectus spanning from junction with arsp and/or sar to inferio-rostral edge of frontal lobe. |
| ips | Intraparietal sulcus | On lateral surface of parietal lobe spanning from inferio-frontal portion to intersection with lu just inferior to midline. |
| lf | Lateral fissure | Separates frontal and parietal lobes from temporal lobe and spans superior-posteriorly from superior-frontal edge of temporal lobe to approximate intersection with sts. |
| lu | Lunate sulcus | Separates parietal and temporal lobes from occipital lobe and spans inferiorly from intersection with ips just inferior to midline. |
| ps | Principal sulcus | Runs posterior-laterally from frontal edge of frontal lobe, ending just before intersection with iar. |
| sar | Superior arcuate rectus | Frontal portion of arcuate rectus running fronto-laterally from intersection with iar and/or arsp. |
| sts | Superior temporal sulcus | Runs superior-posteriorly from inferio-frontal edge of temporal lobe to approximate intersection with lf. |
| spcd | Superior precentral dimple | Possible short lateral fold in frontal lobe superior to arcuate rectus. |
| Larsp_yn | Non-metric: presence/absence of left hemisphere arsp. | |
| Rarsp_yn | Non-metric: presence/absence of right hemisphere arsp. | |
| Lcs_forked | Non-metric: indicates whether the inferior tip of the left cs is forked or unforked. | |
| Rcs_forked | Non-metric: indicates whether the inferior tip of the right cs is forked or unforked. | |
| Lspcd_yn | Non-metric: presence/absence of left hemisphere spcd. | |
| Rspcd_yn | Non-metric: presence/absence of right hemisphere spcd. |
Anatomical characterization of the position on the hemisphere, proximal, and terminal ends of the 10 metric and 6 non-metric cortical-folding traits examined on each brain hemisphere. Left and right hemispheres were collected separately on different days. Non-metric traits are in boldface type.