Bilateral Right Cerebrum.Temporal Lobe.Inferior Temporal Gyrus.Gray Matter.Brodmann area 21 corresponds to cortical tissue in the middle portion of the temporal lobe, extending along the inferior temporal gyrus on both sides and classified cytoarchitectonically as BA21. This region is implicated in high-level auditory and language processing, semantic memory, and multimodal integration of visual and auditory inputs, contributing to the recognition and interpretation of complex stimuli such as speech and objects. Gray matter in BA21 contains pyramidal neurons forming part of association cortices that connect extensively with other temporal, frontal, and parietal regions, supporting functions related to comprehension, contextual interpretation, and aspects of social cognition. There is no direct link for this exact Talairach label; a closely related structure is the Brodmann area 21.
The bilateral right inferior temporal gyrus gray matter in Brodmann area 21 (BA21), as defined in the Talairach 2 mm atlas, is part of the lateral temporal cortex implicated in language, semantic memory, social cognition, and visual object processing, and has been repeatedly linked to genetic influences on cortical structure and function. Twin and imaging-genetics studies indicate high heritability of temporal lobe cortical thickness and surface area, with common variants in genes such as BDNF (e.g., Val66Met), DISC1, and NRG1 associated with alterations in temporal cortical morphology and connectivity that encompass BA21. Large-scale GWAS of brain imaging phenotypes (e.g., ENIGMA consortium) have identified loci influencing temporal cortical thickness and surface area (including variants near KIAA0586, HMGA2, and several intergenic regions), some of which overlap with risk loci for schizophrenia, major depressive disorder, bipolar disorder, and autism spectrum disorder, conditions in which BA21 frequently shows structural or functional abnormalities. BA21 and adjacent superior/middle temporal areas are genetically implicated in language-related traits: FOXP2 and CNTNAP2 variants have been linked to structural and functional alterations in perisylvian temporal cortex, while GWAS of educational attainment, reading ability, and general cognitive function have found polygenic influences that correlate with temporal lobe measures in imaging-genetics analyses. Additionally, GWAS on social communication, empathy, and face/voice processing—traits that rely on temporal semantic and social networks—have identified polygenic architectures whose neural correlates include BA21 activation and volume. Overall, genetic studies support that BA21 is a highly heritable association cortex region whose structure and activity are modulated by many common risk and trait variants, particularly those involved in neurodevelopment, synaptic plasticity, and psychiatric and neurodevelopmental disorders.
Overview generated by GPT-4o (2026).
Region ID: 77
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
This resource is licensed under CC0 1.0 Universal (Public Domain).