{"id":"doi:10.64898/2026.09.17.752514","kind":"article","title":"Connectome-based biophysical modeling of a figure-ground discrimination circuit","authors":["Liu Ziyin","Yifei Lu","Alexander Borst","Sven Dorkenwald","Tomaso Poggio"],"author_count":5,"year":2026,"published":"2026-09-24","venue":"bioRxiv (Cold Spring Harbor Laboratory)","cited_by":0,"doi":"10.64898/2026.09.17.752514","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.64898/2026.09.17.752514","archive_url":"https://space-kitty.com/papers/doi:10.64898/2026.09.17.752514","updated":null,"pmid":null,"pmcid":null,"openalex_id":"W7214161747","pdf_url":"https://www.biorxiv.org/content/biorxiv/early/2026/09/24/2026.09.17.752514.full.pdf","abstract":"Figure-ground discrimination via relative motion represents a highly conserved visual computation essential for uncovering camouflage \\citep{reichardt1983figure,Egelhaaf1985}. Over forty years ago, the Reichardt-Poggio-Hausen (RPH) model proposed a circuit architecture to explain this phenomenon, relying on an inhibitory wide-field pool cell to aggregate global motion and subsequently inhibit elementary motion detectors. Here we combine a whole-brain connectome of Drosophila with biophysical simulations to identify a reciprocal connection between T4a motion detectors and the wide-field ventral Centrifugal Horizontal cell. The anatomical feedback from vCH lands on T4a axon terminals; simulated dendrites generate local direction-selective responses, whereas the terminals become selective for relative motion. The isolated reciprocal circuit is sufficient for this selectivity which is abolished by removing the return inhibition. Opponent-motion and interocular pathways strengthen the same computation. Thus, a single neuron using the biophysical mechanism of shunting inhibition, corresponding to an equilibrium potential close to the resting potential, can support distinct visual operations in separate compartments: local motion in its dendrites and relative motion in its axon.","abstract_license":"CC-BY (publisher license, via OpenAlex)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Visual perception and processing mechanisms"],"details":null,"provenance":"openalex","attribution":"Abstract of \"Connectome-based biophysical modeling of a figure-ground discrimination circuit\" by Liu Ziyin, Yifei Lu, Alexander Borst et al., https://doi.org/10.64898/2026.09.17.752514, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified.","topics":[{"slug":"connectomics","name":"Connectomics & Brain Mapping","domain_slug":"neuroscience"}],"cited_in_dossiers":[]}