{"id":1812,"date":"2020-07-08T15:00:08","date_gmt":"2020-07-08T15:00:08","guid":{"rendered":"https:\/\/cog-ist.com\/?post_type=blog_content&p=1812"},"modified":"2025-08-13T19:29:37","modified_gmt":"2025-08-13T19:29:37","slug":"beyin-bolundugu-zaman-kisi-de-bolunur-mu-yair-pinto","status":"publish","type":"blog_content","link":"https:\/\/cog-ist.com\/en\/blog_content\/beyin-bolundugu-zaman-kisi-de-bolunur-mu-yair-pinto\/","title":{"rendered":"Beyin B\u00f6l\u00fcnd\u00fc\u011f\u00fc Zaman Ki\u015fi De B\u00f6l\u00fcn\u00fcr M\u00fc? \u2014\u00a0Ya\u00efr Pinto"},"content":{"rendered":"

\u00d6zg\u00fcn Metin:\u00a0When you split the brain, do you split the person?<\/a><\/p>\n\n\n\n

Beyin, belki de evrendeki en karma\u015f\u0131k makinedir. Her biri bir\u00e7ok farkl\u0131 mod\u00fcle sahip iki serebral hemisferden (beyin yar\u0131mk\u00fcresi) olu\u015fur. Neyse ki bu ayr\u0131 par\u00e7alar \u00f6zerk de\u011fildir. Hepsi son derece birbiriyle ba\u011flant\u0131l\u0131, tamamen uyum i\u00e7inde tek bir e\u015fsiz varl\u0131k olu\u015fturmak i\u00e7in \u00e7al\u0131\u015f\u0131yorlar: seni.<\/p>\n\n\n\n

Fakat biz bu ahengi yok edersek ne olur? Ya baz\u0131 mod\u00fcller di\u011fer mod\u00fcllerden ba\u011f\u0131ms\u0131z olarak \u00e7al\u0131\u015fmaya ba\u015flarsa? \u0130lgin\u00e7 bir bi\u00e7imde bu, sadece bir d\u00fc\u015f\u00fcnce deneyinden ibaret de\u011fil; baz\u0131 insanlar i\u00e7in bu ger\u00e7ektir.<\/p>\n\n\n\n

Ayr\u0131k beyin (split-brain) olarak adland\u0131r\u0131lan hastalarda corpus callosum (sa\u011f ve sol serebral hemisferler aras\u0131ndaki ana ileti\u015fim yolu), ba\u015fka t\u00fcrl\u00fc kontrol alt\u0131na al\u0131namayan epilepsileri durdurmak i\u00e7in cerrahi olarak kesilir.<\/p>\n\n\n\n

Operasyon epilepsinin durdurulmas\u0131nda etkilidir; bir hemisferde bir n\u00f6ral ate\u015flenme f\u0131rt\u0131nas\u0131 (neural firestorm) ba\u015flarsa, bu ay\u0131rma sayesinde di\u011fer hemisfere yay\u0131lmas\u0131 \u00f6nlenmi\u015f olur. Ancak corpus callosum olmadan hemisferlerin neredeyse hi\u00e7bir bilgi al\u0131\u015fveri\u015f yolu kalmam\u0131\u015ft\u0131r.<\/p>\n\n\n\n

O h\u00e2lde ki\u015fiye ne olur? Par\u00e7alar art\u0131k senkronize edilmiyorsa, beyin h\u00e2l\u00e2 bir ki\u015fi mi \u00fcretiyordur? Roger Sperry ve Michael Gazzaniga adl\u0131 iki n\u00f6robilimci 1960\u2019larda ve 70\u2019lerde bu sorunu ara\u015ft\u0131rmaya koyuldular<\/a>, beyin b\u00f6l\u00fcnd\u00fc\u011f\u00fcnde ki\u015finin b\u00f6l\u00fcnd\u00fc\u011f\u00fcne dair \u015fa\u015f\u0131rt\u0131c\u0131 veriler buldular. Sperry, 1981\u2019de ayr\u0131k beyin \u00e7al\u0131\u015fmas\u0131 sayesinde Nobel T\u0131p \u00d6d\u00fcl\u00fc\u2019n\u00fc kazand\u0131.<\/p>\n\n\n\n

Ara\u015ft\u0131rmac\u0131lar beyni b\u00f6lmenin her bir hemisferde bir ki\u015fi olmak \u00fczere iki ki\u015fi ortaya \u00e7\u0131kard\u0131\u011f\u0131n\u0131 nas\u0131l kan\u0131tlad\u0131lar? G\u00f6rsel bilginin beyine ak\u0131\u015f\u0131n\u0131 kontrol eden zekice bir plan sayesinde.<\/p>\n\n\n\n

\u0130ki g\u00f6z\u00fcn de her iki serebral hemisfere bilgi g\u00f6nderdi\u011fini ve bu ba\u011flant\u0131n\u0131n da karma\u015f\u0131k oldu\u011funu h\u00e2lihaz\u0131rda biliyorlard\u0131. G\u00f6zlerinizi bir noktaya odaklad\u0131\u011f\u0131n\u0131zda, o noktan\u0131n solundaki (sol g\u00f6rme alan\u0131) \u00f6gelerin hepsi sa\u011f hemisferde i\u015flenirken sa\u011f\u0131ndaki \u00f6gelerin (sa\u011f g\u00f6rme alan\u0131) hepsi de sol hemisferde i\u015flenir. Dahas\u0131, sol hemisfer v\u00fccudun sa\u011f taraf\u0131n\u0131 ve dil \u00fcretimini kontrol ederken sa\u011f hemisfer v\u00fccudun sol taraf\u0131n\u0131 kontrol eder.<\/p>\n\n\n\n

Sperry ve Gazzaniga, hastan\u0131n sa\u011f g\u00f6rme alan\u0131na uyaran (stimulus) verdi\u011fi zaman (konu\u015fmadan sorumlu sol hemisfer taraf\u0131ndan i\u015flenir) hasta normal yan\u0131t verdi. Ancak sol g\u00f6rme alan\u0131na uyaran verildi\u011fi zaman (dilsiz sa\u011f hemisfer taraf\u0131ndan i\u015flenir) hasta hi\u00e7bir \u015fey g\u00f6rmedi\u011fini s\u00f6yledi. Yine de sol eli g\u00f6sterilen g\u00f6r\u00fcnt\u00fcy\u00fc \u00e7izebiliyordu. Sol elinin bunu neden yapt\u0131\u011f\u0131 soruldu\u011funda, hasta \u015fa\u015fk\u0131na d\u00f6nm\u00fc\u015ft\u00fc ve hi\u00e7bir fikrinin olmad\u0131\u011f\u0131n\u0131 s\u00f6yledi.<\/p>\n\n\n\n

Burada ne oluyordu? Sol hemisfer sol g\u00f6rme alan\u0131n\u0131 g\u00f6remiyordu, bu y\u00fczden oraya bir uyaran verildi\u011fi zaman hakl\u0131 olarak hi\u00e7bir \u015fey g\u00f6rmedi\u011fini s\u00f6yledi. Yine de, sa\u011f hemisfer uyaran\u0131 g\u00f6rd\u00fc ve bunu sol eli y\u00f6nlendirerek yapabildi\u011fini g\u00f6sterdi. Sperry ve Gazzaniga taraf\u0131ndan \u00e7\u0131kar\u0131lan sonu\u00e7 a\u00e7\u0131kt\u0131: tek bir ayr\u0131k beyin hastas\u0131 asl\u0131nda iki yar\u0131m beyin hastas\u0131 olarak d\u00fc\u015f\u00fcn\u00fclmelidir \u2014 bir \u00e7e\u015fit Siyam ikizi gibi. Sperry, bunun sadece merak\u0131n \u00f6tesine ge\u00e7ti\u011fini savundu, kelimenin tam anlam\u0131yla bilin\u00e7 alan\u0131ndaki materyalizm kavram\u0131n\u0131 kan\u0131tl\u0131yordu. E\u011fer beyin b\u00f6l\u00fcnd\u00fc\u011f\u00fc zaman ki\u015fi de b\u00f6l\u00fcn\u00fcyorsa, bu maddi olmayan ruha pek fazla yer b\u0131rakm\u0131yordu.<\/p>\n\n\n\n

Dava kapand\u0131 m\u0131? Benim i\u00e7in hay\u0131r. Kabul etmeliyiz ki ayr\u0131k beyinli hastalar normal hissediyorlar ve normal davran\u0131yorlar. Ayr\u0131k beyinli bir hasta odaya girerse, ola\u011fand\u0131\u015f\u0131 bir \u015fey fark etmezsiniz. Ve korkun\u00e7 epileptik n\u00f6betlerden kurtulmak d\u0131\u015f\u0131nda tamamen ayn\u0131 olduklar\u0131n\u0131 iddia ediyorlar. E\u011fer o ki\u015fi ger\u00e7ekten b\u00f6l\u00fcnm\u00fc\u015f olsayd\u0131, bu do\u011fru olmazd\u0131.<\/p>\n\n\n\n

\u0130\u015flerin temeline inmek i\u00e7in Amsterdam \u00dcniversitesi\u2019ndeki ekibimle iki ayr\u0131k beyin hastas\u0131n\u0131 test ederek<\/a>, sol g\u00f6rme alan\u0131ndaki nesnelere (sa\u011f hemisferce alg\u0131lanan) do\u011fru yan\u0131t verip vermeyeceklerini de\u011ferlendirirken, ayn\u0131 zamanda s\u00f6zel olarak m\u0131 yoksa sa\u011f elle mi (sol hemsiferce kontrol edilen) yan\u0131t verdiklerini inceleyerek bu temel sorunu tekrar ele ald\u0131k. \u015ea\u015f\u0131rt\u0131c\u0131 bir \u015fekilde bu iki hastada, Sperry ve Gazzaniga\u2019n\u0131n daha \u00f6nce buldu\u011fu sonu\u00e7lardan tamamen farkl\u0131 sonu\u00e7lar bulduk. Hastalar\u0131n her ikisi de sa\u011f ve sol olmak \u00fczere t\u00fcm g\u00f6rme alan\u0131nda uyaranlar\u0131n varl\u0131\u011f\u0131 ve konumu hakk\u0131nda tam fark\u0131ndal\u0131k g\u00f6sterdiler. Sol g\u00f6rme alan\u0131na uyaranlar verildi\u011finde, hastalar hi\u00e7bir \u015fey g\u00f6rmediklerini (veya sa\u011f elle belirtmediklerini) neredeyse hi\u00e7bir zaman s\u00f6ylemediler. Aksine, bir \u015feyin nerede oldu\u011funu ve nereden belirece\u011fini do\u011fru bir \u015fekilde g\u00f6sterdiler.<\/p>\n\n\n\n

Ancak bizim \u00e7al\u0131\u015ft\u0131\u011f\u0131m\u0131z ayr\u0131k beyinli hastalar da tamamen normal de\u011fildiler. G\u00f6rme alan\u0131n\u0131n orta hatt\u0131 boyunca verilen uyaranlar\u0131 k\u0131yaslayamad\u0131lar. Dahas\u0131, sol g\u00f6rme alan\u0131na uyaran verildi\u011finde hasta uyaran\u0131n g\u00f6rsel \u00f6zelliklerini belirtmede daha iyiydi (sa\u011f elle veya s\u00f6zl\u00fc olarak cevap verse bile!) ve sa\u011f g\u00f6rme alan\u0131na bir uyaran verildi\u011finde s\u00f6zl\u00fc olarak etiketlemede (verbal labelling) daha iyiydi (sol eli ile cevap verdi\u011finde bile).<\/p>\n\n\n\n

Bu bulgulara dayanarak yeni bir ayr\u0131k beyin modeli \u00f6nerdik. Beyni b\u00f6ld\u00fc\u011f\u00fcn\u00fczde, h\u00e2l\u00e2 sadece bir ki\u015fi vard\u0131r. Bununla birlikte, bu ki\u015fi her g\u00f6rsel alan i\u00e7in bir tane olmak \u00fczere iki g\u00f6rsel bilgi ak\u0131\u015f\u0131 ya\u015far ve ki\u015fi bu iki ak\u0131\u015f\u0131 birle\u015ftiremez. Sanki senkronize olmayan bir film izliyor; ama burada sorunlu olan ses ve g\u00f6r\u00fcnt\u00fc senkronizasyonu de\u011fil de, iki ak\u0131\u015f da g\u00f6r\u00fcnt\u00fc ak\u0131\u015f\u0131 gibi.<\/p>\n\n\n\n

Dahas\u0131 da var. \u00d6nceki model materyalizm i\u00e7in g\u00fc\u00e7l\u00fc kan\u0131tlar sunarken (beyni b\u00f6l\u00fcnd\u00fc\u011f\u00fcnde, ki\u015fi de b\u00f6l\u00fcn\u00fcr), mevcut anlay\u0131\u015f sadece bilincin gizemini derinle\u015ftiriyor gibi g\u00f6r\u00fcn\u00fcyor. Beyin ikiye b\u00f6l\u00fcnse de yine tek bir ki\u015fiyle kar\u015f\u0131 kar\u015f\u0131ya oluyorsunuz. Bir\u00e7ok mod\u00fclden olu\u015fan beyin nas\u0131l oluyor da sadece bir ki\u015fiyi yarat\u0131yor? Ve bu par\u00e7alar birbirleriyle bile konu\u015fmazken ayr\u0131k beyinliler nas\u0131l bir b\u00fct\u00fcn olarak davranabiliyorlar?<\/p>\n\n\n\n

\u0130LER\u0130 OKUMA \u00d6NER\u0130LER\u0130<\/strong><\/p>\n\n\n\n

Ayr\u0131k beyin kavram\u0131 genel olarak corpus callosotomy (corpus callosumun\u2019un cerrahi olarak kesilmesi) sonras\u0131 hastalar\u0131 i\u00e7in kullan\u0131lsa da tek bu operasyon sonucunda da olu\u015fmaz. Corpus callosum ne kadar hemisferler aras\u0131ndaki en b\u00fcy\u00fck ba\u011flant\u0131 (hem boyut hem de g\u00f6rev olarak) olsa da tek ba\u011flant\u0131 de\u011fildir. Bu nedenle ara\u015ft\u0131rmac\u0131lar yeni bir ameliyat tekni\u011fi olan \u2018commissurotomy\u2019yi (beyin cerrahisindeki kullan\u0131m\u0131yla hemisferler aras\u0131ndaki t\u00fcm ba\u011flar\u0131n kesilmesi) denemi\u015flerdir. Okurlar ilk yap\u0131lan callosotomy ameliyat\u0131 i\u00e7in 1940 y\u0131l\u0131nda Von WAGENEN ve arkada\u015flar\u0131 taraf\u0131ndan \u00e7\u0131kar\u0131lm\u0131\u015f \u201cSurgical Division of Commissural Pathways In the Corpus Callosum<\/a>\u201d adl\u0131 makaleye g\u00f6z atabilirler. Daha sonra deneylenen commisurotomy i\u00e7in ise Bogen ve Vogel taraf\u0131ndan 1965 y\u0131l\u0131nda yaz\u0131lm\u0131\u015f \u201cCerebral Commissurotomy<\/a>\u201d adl\u0131 makaleyi inceleyebilir. Commissurotomy operasyonunun kontrol alt\u0131na al\u0131namayan epilepsi tedavisinde nas\u0131l bir \u00f6nemi oldu\u011funu merak eden okurlar ise 1977 y\u0131l\u0131nda Gazzaniga ve arkada\u015flar\u0131 taraf\u0131ndan \u00e7\u0131kar\u0131lm\u0131\u015f \u201cCerebral Commissurotomy For Control of Intractable Seizures<\/a>\u201d adl\u0131 \u00e7al\u0131\u015fmalar\u0131na bakabilirler. Ayr\u0131ca, ayr\u0131k beyin hastalar\u0131 \u00fczerinde yap\u0131lan \u00e7al\u0131\u015fmalar\u0131 en ba\u015f\u0131ndan g\u00fcn\u00fcm\u00fcze kadar olan yolculu\u011funu merak eden okurlar ise Gazzaniga\u2019n\u0131n 2005 y\u0131l\u0131nda \u00e7\u0131karm\u0131\u015f oldu\u011fu \u201cForty-five Years of Split-Brain Research And Still Going Strong<\/a>\u201d yaz\u0131s\u0131ndan faydalanabilirler. Sperry\u2019nin 1981 y\u0131l\u0131nda nobel kazand\u0131\u011f\u0131 \u00e7al\u0131\u015fmas\u0131n\u0131n detaylar\u0131 i\u00e7in ise buradan faydalanabilirler: https:\/\/www.nobelprize.org\/prizes\/medicine\/1981\/press-release\/<\/a> Ayr\u0131k beyin hastalar\u0131 \u00fczerinde yap\u0131lan testleri ve testlerden elde edilen sonu\u00e7lar\u0131 merak eden okurlar ise Gazzaniga ve LeDoux taraf\u0131ndan \u00e7\u0131kar\u0131lm\u0131\u015f olan \u201cThe Integrated Mind<\/a>\u201d adl\u0131 kitaba g\u00f6z atabilirler.<\/p>","protected":false},"featured_media":1813,"template":"","meta":{"_acf_changed":false},"event_publishing_tags":[769,83,175,94,93,378,518,82,691,64,377,92,174,74,76,66,65,300,75,177,299,471,770,768,96],"kategori":[305],"class_list":["post-1812","blog_content","type-blog_content","status-publish","has-post-thumbnail","hentry","event_publishing_tags-ayrik-beyin","event_publishing_tags-beyin","event_publishing_tags-bilinc","event_publishing_tags-bilis","event_publishing_tags-bilissel-bilim","event_publishing_tags-bilissel-norobilim","event_publishing_tags-bilissel-sinirbilim","event_publishing_tags-brain","event_publishing_tags-cogist","event_publishing_tags-cognition","event_publishing_tags-cognitive-neuroscience","event_publishing_tags-cognitive-science","event_publishing_tags-consciousness","event_publishing_tags-felsefe","event_publishing_tags-mind","event_publishing_tags-neuroscience","event_publishing_tags-norobilim","event_publishing_tags-norobilim-felsefesi","event_publishing_tags-philosophy","event_publishing_tags-philosophy-of-mind","event_publishing_tags-philosophy-of-neuroscience","event_publishing_tags-sinirbilim","event_publishing_tags-sinirbilim-felsefesi","event_publishing_tags-split-brain","event_publishing_tags-zihin","kategori-ceviri"],"acf":[],"_links":{"self":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/blog_content\/1812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/blog_content"}],"about":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/types\/blog_content"}],"version-history":[{"count":0,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/blog_content\/1812\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media\/1813"}],"wp:attachment":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media?parent=1812"}],"wp:term":[{"taxonomy":"event_publishing_tags","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/event_publishing_tags?post=1812"},{"taxonomy":"kategori","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/kategori?post=1812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}