{"id":1488,"date":"2024-12-28T08:05:06","date_gmt":"2024-12-28T13:05:06","guid":{"rendered":"https:\/\/sites.bu.edu\/vision\/?p=1488"},"modified":"2024-12-28T08:06:08","modified_gmt":"2024-12-28T13:06:08","slug":"1488","status":"publish","type":"post","link":"https:\/\/sites.bu.edu\/vision\/2024\/12\/28\/1488\/","title":{"rendered":"How does orientation-tuned normalization spread across the visual field?"},"content":{"rendered":"<h4 style=\"text-align: justify;\"><i>Journal of Neurophysiology (2025)<\/i><br \/>\nMichaela Klimova, Ilona Bloem &amp; Sam Ling<\/h4>\n<div class=\"page\" title=\"Page 2\">\n<div class=\"layoutArea\">\n<div class=\"column\">\n<div class=\"page\" title=\"Page 1\">\n<div class=\"layoutArea\">\n<div class=\"column\">\n<p style=\"text-align: justify;\"><img loading=\"lazy\" src=\"\/vision\/files\/2024\/12\/Screenshot-2024-12-28-at-7.57.58\u202fAM.png\" alt=\"\" width=\"300\" height=\"286\" class=\"wp-image-1489 alignleft\" srcset=\"https:\/\/sites.bu.edu\/vision\/files\/2024\/12\/Screenshot-2024-12-28-at-7.57.58\u202fAM.png 1314w, https:\/\/sites.bu.edu\/vision\/files\/2024\/12\/Screenshot-2024-12-28-at-7.57.58\u202fAM-636x607.png 636w, https:\/\/sites.bu.edu\/vision\/files\/2024\/12\/Screenshot-2024-12-28-at-7.57.58\u202fAM-1024x977.png 1024w, https:\/\/sites.bu.edu\/vision\/files\/2024\/12\/Screenshot-2024-12-28-at-7.57.58\u202fAM-768x733.png 768w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/>Visuocortical responses are regulated by gain control mechanisms, giving rise to fundamental neural and perceptual phenomena such as surround suppression. Suppression strength, determined by the composition and relative properties of stimuli, controls the strength of neural responses in early visual cortex, and in turn, the subjective salience of the visual stimulus. Notably, suppression strength is modulated by feature similarity; for instance, responses to a center-surround stimulus in which the components are collinear to each other are weaker than when they are orthogonal. However, this feature-tuned aspect of normalization, and how it may affect the gain of responses, has been understudied. Here, we examine the contribution of the tuned component of suppression to contrast response modulations across the visual field. To do so, we used functional magnetic resonance imaging (fMRI) to measure contrast response functions (CRFs) in early visual cortex (areas V1 \u2013 V3) in 10 observers while they viewed full-field center-surround gratings. The center stimulus varied in contrast between 2.67-96%, and was surrounded by a parallel or orthogonal surround at full contrast. We found substantially stronger suppression of responses when the surround was parallel to the center, manifesting as shifts in the population CRF. The magnitude of the CRF shift was strongly dependent on voxel spatial preference, and seen primarily in voxels whose receptive field spatial preference corresponds to the area straddling the center-surround boundary in our display, with little-to-no modulation elsewhere.<\/p>\n<p style=\"text-align: justify;\"><a href=\"\/vision\/files\/2024\/12\/Klimova_Bloem_Ling_TunedNormalizationCRF.pdf\">Download it here.<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Journal of Neurophysiology (2025) Michaela Klimova, Ilona Bloem &amp; Sam Ling Visuocortical responses are regulated by gain control mechanisms, giving rise to fundamental neural and perceptual phenomena such as surround suppression. Suppression strength, determined by the composition and relative properties of stimuli, controls the strength of neural responses in early visual cortex, and in turn, [&hellip;]<\/p>\n","protected":false},"author":8254,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/posts\/1488"}],"collection":[{"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/users\/8254"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/comments?post=1488"}],"version-history":[{"count":3,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/posts\/1488\/revisions"}],"predecessor-version":[{"id":1492,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/posts\/1488\/revisions\/1492"}],"wp:attachment":[{"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/media?parent=1488"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/categories?post=1488"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.bu.edu\/vision\/wp-json\/wp\/v2\/tags?post=1488"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}