{"id":4267,"date":"2018-09-24T10:01:41","date_gmt":"2018-09-24T07:01:41","guid":{"rendered":"https:\/\/umram.bilkent.edu.tr\/?p=4267"},"modified":"2018-09-24T10:06:46","modified_gmt":"2018-09-24T07:06:46","slug":"master-tez-sunumu-gorkem-er","status":"publish","type":"post","link":"https:\/\/umram.bilkent.edu.tr\/index.php\/tr\/2018\/09\/24\/master-tez-sunumu-gorkem-er\/","title":{"rendered":"Master Tez Sunumu: G\u00f6rkem Er"},"content":{"rendered":"<p><a href=\"https:\/\/umram.bilkent.edu.tr\/index.php\/teams\/gorkem-er\/\">G\u00f6rkem Er\u00a0<\/a>13 Eyl\u00fcl 2018 tarihinde y\u00fcksek lisans tezini ba\u015far\u0131yla sundu.<\/p>\n<p>UMRAM&#8217;da y\u00fckseklisans \u00e7al\u0131\u015fmalar\u0131n\u0131 s\u00fcrd\u00fcren G\u00f6rkem Er, <a href=\"http:\/\/w3.bilkent.edu.tr\/bilkent\/\">Bilkent \u00dcniversitesi<\/a>&#8216;nde dan\u0131\u015fman\u0131 <a href=\"https:\/\/umram.bilkent.edu.tr\/index.php\/teams\/huseyin-boyaci\/\">H\u00fcseyin Boyac\u0131<\/a> ile birlikte <a href=\"http:\/\/web2.bilkent.edu.tr\/neuroscience\/\">Neuroscience Master<\/a> program\u0131na devam etmektedir.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Tez Ba\u015fl\u0131\u011f\u0131<\/strong>:\u00a0Kontrast ne B\u00fcy\u00fckl\u00fc\u011f\u00fcn Hareket Alg\u0131s\u0131ndaki Rol\u00fc: V1 Ve MT\u2019deki \u00c7Evre Ve Merkez Etkilesimlerinin FMRI ve Davrani\u015f\u015fal Deneylerle \u0130ncelenmesi.<\/p>\n<p><strong>Abstract:<\/strong>\u00a0Davran\u0131\u015f\u015fal deneyler, izleyicinin hareket eden g\u00f6rsel uyaran\u0131n y\u00f6n\u00fcn\u00fc tayin etme becerisinin uyaran\u0131n boyutunun b\u00fcy\u00fcmesiyle att\u0131\u011f\u0131n\u0131, fakat bu art\u0131\u015f\u0131n uyar\u0131c\u0131 d\u00fc\u015f\u00fck kontrasta sahipse ger\u00e7ekle\u015fti\u011fini, y\u00fcksek kontrasta sahipse de y\u00f6n\u00fc tayin etme becerisinin d\u00fc\u015ft\u00fc\u011f\u00fcn\u00fc g\u00f6stermi\u015ftir. Kortikal b\u00f6lge \u201dorta temporal\u201d (MT+) deki n\u00f6ronlar\u0131n\u0131n al\u0131m alan\u0131 organizasyonunun bu g\u00f6zlemlenen konrast- b\u00fcy\u00fckl\u00fck etkile\u015fiminden kaynaklanan alg\u0131 etkisine sebep oldu\u011fu ileri s\u00fcr\u00fclmi\u015ft\u00fcr. Bu \u00f6nermeyi destekeyen deliller de temin edilmi\u015ftirdir literat\u00fcrde. Fakat, daha \u00f6nceki ara\u015ft\u0131rmalar, MT b\u00f6lgesinin aktivitesinin bahsedilen alg\u0131sal etkiye yol a\u00e7an tek sorumlu b\u00f6lge oldu\u011funu kesin bir \u015fekilde test edip g\u00f6stermemi\u015ftir.<\/p>\n<p>Bu ara\u015ft\u0131rmada, hareket alg\u0131s\u0131nda b\u00fcy\u00fckl\u00fck-kontrast etkile\u015fimini i\u015fleyen b\u00f6lgeyi bulmak ama\u00e7lanmaktad\u0131r. Bu sebeple, g\u00f6rsel korteks (V1) ve MT+\u2019nin aktivite grafiklerinin alg\u0131sal sonu\u00e7lara olan rol\u00fcn\u00fc incelenmektedir. \u0130lk olarak, davran\u0131\u015f\u015fsal deneylerle k\u00fc\u00e7\u00fck ve b\u00fcy\u00fck (1.67 ve 8.05 derece) boyutlarda hareket eden ve d\u00fc\u015f\u00fck (% 2) veya y\u00fcksek (% 99) kontrast seviyesinde Gaborlar\u0131 \u00e7evresel b\u00f6lgede (fiksasyon b\u00f6lgesine uzakl\u0131k sa\u011fdan ve soldan 8.02 derece) g\u00f6stererek literat\u00fcrdeki sonu\u00e7lar\u0131 do\u011frulayan sonu\u00e7lar\u0131 bulduk. Hareket y\u00fcn\u00fcn\u00fcn do\u011fru ay\u0131rt edildi\u011fini g\u00f6steren e\u015fik de\u011ferleri (% 79) iki-alternatif zorunlu se\u00e7enek (2AFC) tasar\u0131m\u0131 ile on bir ki\u015fi i\u00e7in \u00f6l\u00e7\u00fcld\u00fc. Daha \u00f6nceki ara\u015ft\u0131rma sonuclar\u0131 ile \u00f6rt\u00fc\u015ferek, hareket y\u00f6n\u00fcn\u00fc do\u011fru ay\u0131rt eden e\u015fik de\u011ferinin uyar\u0131c\u0131 d\u00fc\u015f\u00fck kontrasta sahipken uyar\u0131c\u0131n\u0131n b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fcn artmas\u0131yla azald\u0131\u011f\u0131n\u0131; y\u00fcksek kontrastl\u0131yken ise, uyar\u0131c\u0131n\u0131n b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fcn artmas\u0131yla birlikte artt\u0131rd\u0131\u011f\u0131n\u0131 g\u00f6zlemledik.<\/p>\n<p>Ara\u015ft\u0131rman\u0131n ikinci a\u015famas\u0131nda alt\u0131 kat\u0131l\u0131mc\u0131, davran\u0131\u015f\u015fsal deneydeki uzaysal ve kontrast seviyelerin ayn\u0131 tutuldu\u011fu blok tasar\u0131ml\u0131 fMRI ara\u015ft\u0131rmas\u0131na\u00a0kat\u0131ld\u0131. Biz ilk olarak her kat\u0131l\u0131mc\u0131 i\u00e7in, yer-belirleme \u00e7ekimleri ile V1 ve MT+ b\u00f6lgelerini temsil eden ilgi alanlar\u0131 (ROI) belirledik. Daha sonra, bu b\u00f6lgeler i\u00e7erisinde ba\u011f\u0131ms\u0131z bir &#8216;yer belirleme&#8217; (localizer) ile k\u00fc\u00e7\u00fck boyutta (1.06 derece) uyar\u0131c\u0131y\u0131 i\u015fleyen \u2019alt b\u00f6lge\u2019 (sub-ROI) belirledik. Bu kurgu sayesinde, b\u00fcy\u00fck ve k\u00fc\u00e7\u00fck boyuttaki uyar\u0131c\u0131lar\u0131n b\u00fct\u00fcn \u00e7ekim boyunca alt-b\u00f6lgeyi uyarmas\u0131na izin verdik. Bu sayede, alt b\u00f6lgede g\u00f6zlemlenen fMRI aktivitesi de\u011fi\u015fikli\u011fi \u00e7evrenin merkeze olan etkisini \u00f6n plana \u00e7\u0131karacakt\u0131. Uyar\u0131c\u0131n\u0131n merkezine verilen MT+ aktivitesinin \u0327cevresel b\u00f6lge d\u00fc\u015f\u00fck kontrasta sahipken artt\u0131\u011f\u0131n\u0131, y\u00fcksek kontrasta sahipken de\u011fi\u015fmedi\u011fini g\u00f6zlemledik. Bununla birikte, uyar\u0131c\u0131n\u0131n merkezine verilen V1 aktivitesininin \u00e7evresel b\u00f6lge y\u00fcksek kontrasta sahip oldu\u011funda artt\u0131\u011f\u0131n\u0131, d\u00fc\u015f\u00fck kontrasta sahipken de\u011fi\u015fmedi\u011fini g\u00f6zlemledik. Di\u011fer bir deyi\u015fle, uyar\u0131c\u0131 d\u00fc\u015f\u00fck kontrasta sahip oldu\u011funda, \u00e7evresel b\u00f6lgenin merkezi i\u015fleyen MT+ n\u00f6ronlar\u0131na etkisinin destekleyici (facilitative) oldug \u0306unu g\u00f6zlemledik. Bu n\u00f6ronal iyili\u015fme (neural facilitation) davran\u0131\u015f\u015fal deneydeki d\u00fc\u015f\u00fck kontrastl\u0131 uyar\u0131c\u0131n\u0131n b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fcn artmas\u0131yla g\u00f6zlemlenen performans art\u0131\u015f\u0131n\u0131 a\u00e7\u0131klar niteliktedir. Bu sonu\u00e7lar, merkez-\u00e7evre etkile\u015fiminin V1 ve MT+ b\u00f6lgeleri i\u00e7in ayr\u0131\u015ft\u0131\u011f\u0131n\u0131, b\u00fcy\u00fckl\u00fck-kontrast etkile\u015fiminin MT+ b\u00f6lgesinde ba\u015flad\u0131\u011f\u0131na delil g\u00f6stermektedir.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>G\u00f6rkem Er\u00a013 Eyl\u00fcl 2018 tarihinde y\u00fcksek lisans tezini ba\u015far\u0131yla sundu. UMRAM&#8217;da y\u00fckseklisans \u00e7al\u0131\u015fmalar\u0131n\u0131 s\u00fcrd\u00fcren G\u00f6rkem Er, Bilkent \u00dcniversitesi&#8216;nde dan\u0131\u015fman\u0131 H\u00fcseyin Boyac\u0131 ile birlikte Neuroscience Master program\u0131na devam etmektedir. &nbsp; Tez Ba\u015fl\u0131\u011f\u0131:\u00a0Kontrast ne B\u00fcy\u00fckl\u00fc\u011f\u00fcn Hareket Alg\u0131s\u0131ndaki Rol\u00fc: V1 Ve MT\u2019deki \u00c7Evre Ve Merkez Etkilesimlerinin FMRI ve Davrani\u015f\u015fal Deneylerle \u0130ncelenmesi. Abstract:\u00a0Davran\u0131\u015f\u015fal deneyler, izleyicinin hareket eden g\u00f6rsel uyaran\u0131n [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":4264,"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\/4267"}],"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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/comments?post=4267"}],"version-history":[{"count":2,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/4267\/revisions"}],"predecessor-version":[{"id":4269,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/posts\/4267\/revisions\/4269"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media\/4264"}],"wp:attachment":[{"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/media?parent=4267"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/categories?post=4267"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/umram.bilkent.edu.tr\/index.php\/wp-json\/wp\/v2\/tags?post=4267"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}