Bilateral Right Cerebrum.Temporal Lobe.Inferior Temporal Gyrus.Gray Matter.Brodmann area 20 corresponds to association cortex in the ventral temporal lobe, located on the inferior surface of the temporal lobe lateral to the fusiform gyrus and anterior to occipitotemporal regions. Cytoarchitectonically defined as Brodmann area 20, this region participates in high-level visual processing, including object recognition, complex feature integration, and aspects of semantic processing related to visual stimuli. It receives input from primary and secondary visual areas and projects to multimodal association cortices, contributing to the linkage of visual information with memory and meaning. Functionally, it forms part of the ventral visual stream (“what” pathway) and is implicated in recognition of faces, objects, and scenes, as well as in the retrieval of conceptual knowledge tied to visual experience. There is no direct link for “Brodmann area 20”; a related structure is the Temporal lobe.
The bilateral right inferior temporal gyrus (ITG) gray matter in Brodmann area 20 is part of the ventral visual stream and high-level object and face processing networks, and genetic associations involving this region largely emerge from imaging genetics and GWAS of brain structure and function rather than region-specific candidate-gene studies. Large-scale neuroimaging GWAS (e.g., ENIGMA, UK Biobank) have identified multiple loci influencing temporal lobe cortical thickness and surface area—including variants near genes such as HMGA2, KIAA0586, WNT3, MIR137, and those in neurodevelopmental and synaptic pathways—that show effects spanning inferior temporal and adjacent visual association cortices, though these findings are often reported at the level of “temporal cortex” or “inferior temporal/ventral temporal” rather than Talairach BA20. Polygenic risk for schizophrenia, bipolar disorder, autism spectrum disorder, and major depressive disorder has been associated with altered temporal lobe morphology and functional activation patterns, including in inferior temporal regions involved in social perception and semantic processing; risk variants in synaptic, glutamatergic, and neurodevelopmental genes (such as CACNA1C, GRIN2A, and others) contribute to these network-level alterations. GWAS of face recognition ability, language and reading traits, and visual object recognition suggest that common genetic variants influencing these cognitive phenotypes exert their effects via ventral temporal circuitry, including the ITG and fusiform gyrus, although specific SNP–BA20 mappings remain coarse. In neurodegenerative disease, APOE ε4 and other Alzheimer’s disease risk loci are linked to atrophy patterns that prominently involve temporal association cortex, with imaging genetics studies showing that APOE-related cortical thinning and amyloid burden extend into inferior temporal and BA20-adjacent regions. Overall, genetic influences on this ITG/BA20 region are best characterized as part of distributed temporal and ventral visual networks implicated in neurodevelopmental, psychiatric, and neurodegenerative disorders, with current GWAS and imaging-genetic findings providing robust but relatively macroscale associations rather than finely resolved, BA20-specific genetic signatures.
Overview generated by GPT-4o (2026).
Region ID: 13
Hemisphere: bilateral
Atlas: Talairach labels 2mm
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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