The bilateral Left Cerebrum.Parietal Lobe.Inferior Parietal Lobule.Gray Matter.Brodmann area 40 corresponds to a segment of the inferior parietal cortex, classically encompassing the supramarginal gyrus and adjacent cortex in the posterior parietal lobe. This region is involved in multimodal sensory integration, including tactile, visual, and auditory inputs, and plays critical roles in language processing (especially phonological and articulatory aspects), spatial attention, praxis, and aspects of working memory. Functionally, it contributes to the dorsal stream of information processing, supporting sensorimotor transformations and higher-order cognitive operations such as calculation and tool use. Lesions in this area can be associated with syndromes such as conduction aphasia, apraxia, and components of Gerstmann or neglect syndromes. There is no direct link for Brodmann area 40; a related structure is the Inferior parietal lobule.
The inferior parietal lobule (IPL; Brodmann area 40) of the left parietal lobe, as defined in the Talairach 1 mm atlas, has been implicated in multiple genetic and genome-wide association studies through its roles in language, numerical cognition, attention, and social cognition. Structural and functional variation in this region has been associated with common variants in genes affecting synaptic plasticity and neurodevelopment, including FOXP2, CNTNAP2, and DCDC2 in studies of language, dyslexia, and developmental speech and reading disorders, as well as genes such as NRGN, GRIN2B, and BDNF in imaging-genetics work linking polymorphisms to cortical thickness, gray matter volume, and connectivity in parietal networks. Large-scale GWAS and imaging-GWAS (e.g., ENIGMA and UK Biobank consortia) have identified polygenic influences on IPL volume and surface area, implicating broad neurodevelopmental loci (e.g., on chromosomes 3p, 6p, and 17q) and demonstrating genetic correlations between IPL morphology and general cognitive ability, educational attainment, and risk for neuropsychiatric disorders including schizophrenia, major depressive disorder, autism spectrum disorder, and attention-deficit/hyperactivity disorder, often via distributed parietal–frontal networks. In addition, parietal lobe and IPL involvement has been repeatedly observed in GWAS-informed studies of Alzheimer’s disease and other dementias, where risk loci such as APOE ε4, CLU, and PICALM show effects on parietal atrophy and default mode network dysfunction that encompass BA40, underscoring a polygenic and highly distributed pattern of genetic risk affecting this associative parietal hub.
Overview generated by GPT-4o (2026).
Region ID: 878
Hemisphere: bilateral
Atlas: Talairach labels 1mm
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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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