The bilateral Right Cerebrum Occipital Lobe Middle Occipital Gyrus Gray Matter Brodmann area 18 corresponds to a portion of the secondary visual cortex (V2) located in the middle portion of the occipital lobe, adjacent to the primary visual cortex (Brodmann area 17). This region participates in early-stage visual processing beyond simple detection of light and dark, contributing to the analysis of orientation, spatial frequency, contours, and more complex visual patterns. It forms part of a distributed visual network that relays processed information to higher-order dorsal and ventral visual pathways involved in motion perception, object recognition, and spatial relationships. Cytoarchitectonically, Brodmann area 18 displays a distinct laminar organization characteristic of visual association cortex, with dense thalamocortical input and extensive intracortical and callosal connections supporting binocular and integrative visual functions. Brodmann area 18
The bilateral right middle occipital gyrus gray matter in Brodmann area 18 (secondary visual cortex, V2) has been implicated in several genetic and GWAS findings, largely through imaging‑genetics studies rather than single‑region candidate analyses. Twin studies and SNP‑based heritability work show that occipital lobe cortical thickness and surface area, including BA18, are strongly heritable, with notable contributions from variants in genes involved in synaptic development and axon guidance (e.g., NRGN, CADM2, DCC) and general brain morphometry loci such as those near HMGA2 and IGF1. Large neuroimaging GWAS consortia (ENIGMA, UK Biobank) have linked common variants to occipital cortical measures and visual network connectivity, and polygenic scores for educational attainment and general cognitive ability correlate with structural and functional metrics in extrastriate visual cortex, suggesting a role in visuo‑spatial and reading‑related processes. Genetic associations with neurodevelopmental and neuropsychiatric disorders—including schizophrenia, autism spectrum disorder, and major depressive disorder—often show altered activation or morphology in BA18 for carriers of risk alleles in synaptic and neuroplasticity genes such as BDNF, GRM3, and CACNA1C, although these findings generally implicate broader visual and associative networks rather than this region alone. GWAS of migraine and visual aura, as well as rare variant and linkage studies in familial visual processing disorders and dyslexia, have reported occipital and BA18 involvement, with candidate loci in glutamatergic and GABAergic signaling pathways, but specific, robust SNP–region associations for the right BA18 middle occipital gyrus at 1 mm Talairach resolution remain limited, and most evidence is indirect via traits affecting visual cortex structure and function.
Overview generated by GPT-4o (2026).
Region ID: 307
Hemisphere: bilateral
Atlas: Talairach labels 1mm
Full Quality Version: Download MP4
Full Quality Version: Download MP4
Wali Sidiqyar*, Gaurav Rudravaram*, Elyssa M. McMaster, Trent M. Schwartz, Adam M. Saunders, Kurt G. Schilling, Bennett A. Landman "Introducing SPINS: A Shared Public Visualization Library of Neuroanatomical Structures." Medical Imaging with Deep Learning- short paper
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