{"pk":31778,"title":"Simulating Tilt Illusions with Lateral Inhibition and a Virtual Axis","subtitle":null,"abstract":"When a vertical test stimulus is presented\nsimultaneously within a surrounding stimulus of\norientation 10-30° clockwise from vertical, the test\nstimulus appears slightly counter-clockwise from\nvertical. In contrast, when the surrounding stimulus\nis 60-80° clockwise from vertical, the test stimulus\nappears slightly clockwise from vertical. Lateral\ninhibition between orientation-selective neurons can\naccount for the former effect (repulsion), but not for\nthe latter effect (attraction). H o w e v e r , if an\northogonal \"virtual axis\" is also present and exerts its\no w n lateral inhibition, both effects can be accounted\nfor. A mathematical m o d e l demonstrates\nquantitatively h o w this m a y occur in the visual\nsystem. O n e simulation with narrowly tuned\norientation-selectivity functions produced tilt\nillusions of similar magnitude to that observed with\nh u m a n s at normal presentation durations. A\nsimulation with m o r e broadly tuned functions\nproduced tilt illusions of m u c h greater magnitude, as\nare found with h u m a n s at very short presentation\ndurations. Based on the model's performance, h u m a n\nperformance and neurophysiological data, it is\nsuggested that: 1) lateral inhibition m a y be the\nimmediate cause of both direct and indirect tilt\nillusions, and 2) the \"virtual axis\" m a y be a real\nneural mechanism and m a y be found in greater\nproportion in extrastriate cortex than in striate cortex.","language":"eng","license":{"name":"","short_name":"","text":null,"url":""},"keywords":[],"section":"Submitted Presentations","is_remote":true,"remote_url":"https://escholarship.org/uc/item/9v519363","frozenauthors":[{"first_name":"Michael","middle_name":"J.","last_name":"Spivey-Knowlton","name_suffix":"","institution":"University of California. Los Angeles","department":""}],"date_submitted":null,"date_accepted":null,"date_published":"1993-01-01T18:00:00Z","render_galley":null,"galleys":[{"label":"PDF","type":"pdf","path":"https://journalpub.escholarship.org/cognitivesciencesociety/article/31778/galley/22846/download/"}]}