The left Frontal Inf Oper (Left) region in the AAL2 atlas corresponds to the opercular part of the left inferior frontal gyrus, a portion of the frontal lobe located above the Sylvian (lateral) fissure and posterior to the triangular part. This region is part of the broader inferior frontal gyrus complex and contributes to language-related functions such as phonological processing, speech production, and aspects of syntactic parsing, often overlapping with components of Broca’s area. Cytoarchitectonically, it is associated mainly with Brodmann area 44, characterized by granular frontal cortex organization and dense reciprocal connections with premotor, temporal, and parietal regions involved in auditory and motor aspects of language. There is no direct Wikipedia article for “Frontal Inf Oper,” but it is contained within the inferior frontal gyrus: Inferior frontal gyrus.
The left inferior frontal gyrus, opercular part (Frontal_Inf_Oper_L in the AAL2 atlas), encompassing a key segment of Broca’s area, has been implicated in multiple genetic and GWAS-based associations involving language, cognitive control, and psychiatric risk. Imaging genetics studies show that common variants in genes related to synaptic plasticity and cortical development—such as CNTNAP2, FOXP2, KIAA0319, and DCDC2—are associated with structural and functional variability in this region, including altered activation during phonological and syntactic processing and differences in local gray matter volume. Large-scale GWAS of brain imaging phenotypes (e.g., from UK Biobank and ENIGMA) have identified loci influencing cortical thickness and surface area in inferior frontal regions, often mapping to genes involved in neurodevelopmental pathways, axon guidance, and transcriptional regulation, although specific AAL2 subregions are rarely isolated in these analyses. Genetic risk for developmental language disorder and dyslexia has been linked to atypical activation and connectivity of the left inferior frontal operculum, and polygenic scores for educational attainment and general cognitive ability show associations with structural and functional measures in this area. Furthermore, schizophrenia, bipolar disorder, and major depression GWAS have implicated neurodevelopmental and synaptic genes whose carriers exhibit altered inferior frontal activation during working memory and inhibitory control tasks, and autism spectrum disorder risk variants have been associated with atypical language-related networks that prominently involve the left inferior frontal gyrus, including its opercular subdivision.
Overview generated by GPT-4o (2026).
Region ID: 2301
Hemisphere: left
Atlas: AAL2
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Full Quality Version: Download MP4
Full Quality Version: Download MP4
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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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