{"id":11542,"date":"2021-04-07T14:54:03","date_gmt":"2021-04-07T11:54:03","guid":{"rendered":"https:\/\/umram.bilkent.edu.tr\/?p=11542"},"modified":"2021-04-07T14:54:03","modified_gmt":"2021-04-07T11:54:03","slug":"neural-correlates-of-metacontrast-masking-across-different-contrast-polarities-2","status":"publish","type":"post","link":"https:\/\/umram.bilkent.edu.tr\/index.php\/tr\/2021\/04\/07\/neural-correlates-of-metacontrast-masking-across-different-contrast-polarities-2\/","title":{"rendered":"Neural correlates of metacontrast masking across different contrast polarities"},"content":{"rendered":"<p>EEG laboratuvar\u0131ndan \u00d6zel Say\u0131ya bir katk\u0131: G\u00f6rsel Sistemin Yap\u0131s\u0131 ve \u0130\u015flevi (<a href=\"https:\/\/www.springer.com\/journal\/429\/updates\/18231902\">https:\/\/www.springer.com\/journal\/429\/updates\/18231902<\/a>).<br \/>\nLisans\u00fcst\u00fc ara\u015ft\u0131rmac\u0131m\u0131z <a href=\"https:\/\/umram.bilkent.edu.tr\/index.php\/teams\/alaz-aydin\/\">Alaz Ayd\u0131n<\/a>, \u201cmeta-kontrast maskeleme\u201d ad\u0131 verilen g\u00fc\u00e7l\u00fc bir ill\u00fczyonu ara\u015ft\u0131rd\u0131. Buna g\u00f6re, bulgular ayn\u0131 zamanda g\u00f6rsel yollar i\u00e7indeki \/ aras\u0131ndaki etkile\u015fimlere de \u0131\u015f\u0131k tutmaktad\u0131r. Daha fazla bilgi i\u00e7in l\u00fctfen \u015fu adresi ziyaret edin: <a href=\"http:\/\/doi.org\/10.1007\/s00429-021-02260-5\">http:\/\/doi.org\/10.1007\/s00429-021-02260-5<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>Abstract<\/p>\n<p>Metacontrast masking is a powerful illusion to investigate the dynamics of perceptual processing and to control conscious visual perception. However, the neural mechanisms underlying this fundamental investigative tool are still debated. In the present study, we examined metacontrast masking across different contrast polarities by employing a contour discrimination task combined with EEG (Electroencephalography). When the target and mask had the same contrast polarity, a typical U-shaped metacontrast function was observed. A change in mask polarity (i.e., opposite mask polarity) shifted this masking function to a monotonic increasing function such that the target visibility was strongly suppressed at stimulus onset asynchronies less than 50\u00a0ms. This transition in metacontrast function has been typically interpreted as an increase in intrachannel inhibition of the sustained activities functionally linked to object visibility and identity. Our EEG analyses revealed an early (160\u2013300\u00a0ms) and a late (300\u2013550\u00a0ms) spatiotemporal cluster associated with this effect of polarity. The early cluster was mainly over occipital and parieto-occipital scalp sites. On the other hand, the later modulations of the evoked activities were centered over parietal and centro-parietal sites. Since both of these clusters were beyond 160\u00a0ms, the EEG results point to late recurrent inhibitory mechanisms. Although the findings here do not directly preclude other proposed mechanisms for metacontrast, they highlight the involvement of recurrent intrachannel inhibition in metacontrast masking.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>EEG laboratuvar\u0131ndan \u00d6zel Say\u0131ya bir katk\u0131: G\u00f6rsel Sistemin Yap\u0131s\u0131 ve \u0130\u015flevi (https:\/\/www.springer.com\/journal\/429\/updates\/18231902). Lisans\u00fcst\u00fc ara\u015ft\u0131rmac\u0131m\u0131z Alaz Ayd\u0131n, \u201cmeta-kontrast maskeleme\u201d ad\u0131 verilen g\u00fc\u00e7l\u00fc bir ill\u00fczyonu ara\u015ft\u0131rd\u0131. Buna g\u00f6re, bulgular ayn\u0131 zamanda g\u00f6rsel yollar i\u00e7indeki \/ aras\u0131ndaki etkile\u015fimlere de \u0131\u015f\u0131k tutmaktad\u0131r. Daha fazla bilgi i\u00e7in l\u00fctfen \u015fu adresi ziyaret edin: http:\/\/doi.org\/10.1007\/s00429-021-02260-5 &nbsp; Abstract Metacontrast masking is a powerful [&hellip;]<\/p>\n","protected":false},"author":7,"featured_media":11538,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[445],"tags":[],"_links":{"self":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/11542"}],"collection":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/comments?post=11542"}],"version-history":[{"count":1,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/11542\/revisions"}],"predecessor-version":[{"id":11543,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/11542\/revisions\/11543"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media\/11538"}],"wp:attachment":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media?parent=11542"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/categories?post=11542"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/tags?post=11542"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}