The bilateral Left Cerebrum.Temporal Lobe.Middle Temporal Gyrus.Gray Matter.Brodmann area 39 corresponds primarily to the angular gyrus region within the inferior parietal lobule at the posterior end of the superior and middle temporal regions, as defined in the Talairach 1 mm atlas. Brodmann area 39 is a multimodal association cortex that integrates visual, auditory, and somatosensory information and is implicated in language-related functions (such as reading, writing, and semantic processing), number processing, spatial cognition, memory retrieval, and aspects of social cognition and theory of mind. It forms part of the posterior segment of the language network and is often involved in the dorsal and ventral pathways linking temporal and frontal language areas; lesions here can contribute to alexia, agraphia, and components of receptive aphasia. Although functionally bilateral, the left-dominant region is particularly associated with higher-order linguistic and symbolic operations. There is no direct Wikipedia article for this exact Talairach label; a closely related structure is the Angular gyrus.
The bilateral middle temporal gyrus (MTG) in Brodmann area 39, often overlapping the angular and posterior superior temporal regions implicated in language, semantic processing, and default-mode network function, has been indirectly linked to multiple genetic associations through imaging-genetics and GWAS of brain structure, cognition, and psychiatric disease. Large-scale MRI GWAS (e.g., ENIGMA, UK Biobank) report heritability of temporal lobe cortical thickness and surface area, with common variants in genes such as HMGA2, IGF1, MIR924HG, and others influencing temporal cortical morphology, though effects are generally diffuse rather than uniquely specific to BA39. BA39/MTG gray matter volume and cortical thickness have been associated with polygenic risk scores for schizophrenia, major depressive disorder, and autism spectrum disorder, consistent with functional imaging findings of language and social-cognitive abnormalities in these conditions. In Alzheimer’s disease and related dementias, variants in APOE (especially ε4), CLU, PICALM, and other AD risk genes correlate with atrophy patterns that include the posterior temporal and parietal association cortices, overlapping BA39, and with altered connectivity in temporoparietal default-mode hubs. GWAS of reading ability and dyslexia highlight genes involved in neuronal migration and axonal guidance (e.g., DCDC2, KIAA0319, ROBO1), with structural and functional differences often observed in temporoparietal language regions that encompass BA39; similarly, genetic influences on verbal IQ, semantic fluency, and educational attainment have been linked to variation in temporal and temporoparietal cortex. Overall, the genetic architecture of this region reflects polygenic, pleiotropic effects where variants shaping neurodevelopment, synaptic function, myelination, and neurodegeneration contribute to interindividual differences in BA39 structure and function, and to susceptibility for language-related traits, cognitive ability, and neuropsychiatric and neurodegenerative disorders.
Overview generated by GPT-4o (2026).
Region ID: 703
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
This resource is licensed under CC0 1.0 Universal (Public Domain).