{"id":1830,"date":"2020-09-02T15:00:51","date_gmt":"2020-09-02T15:00:51","guid":{"rendered":"https:\/\/cog-ist.com\/?post_type=blog_content&p=1830"},"modified":"2025-08-13T20:28:52","modified_gmt":"2025-08-13T20:28:52","slug":"norobilimde-karmasikligin-onemi-joel-frohlich","status":"publish","type":"blog_content","link":"https:\/\/cog-ist.com\/en\/blog_content\/norobilimde-karmasikligin-onemi-joel-frohlich\/","title":{"rendered":"N\u00f6robilimde Karma\u015f\u0131kl\u0131\u011f\u0131n \u00d6nemi \u2014 Joel Frohlich"},"content":{"rendered":"

\u00d6zg\u00fcn Ad\u0131:\u00a0Fugue of Life: Why Complexity Matters in Neuroscience<\/a><\/p>\n\n\n\n

Joel Frohlich Kaliforniya \u00dcniversitesi, Los Angeles\u2019ta, Martin Monti\u2019nin laboratuvar\u0131nda bilin\u00e7 \u00fczerine \u00e7al\u0131\u015fan bir doktora sonras\u0131 ara\u015ft\u0131rmac\u0131s\u0131d\u0131r. Ayn\u0131 zamanda <\/em>Knowing Neurons<\/em><\/a>\u2019ta bir i\u00e7erik \u00fcrecitisidir.<\/em><\/p>\n\n\n\n

\u0130nsanlar sadeli\u011fi sever. Zaman ilerledik\u00e7e kurumsal markalar giderek minimalist bir hal al\u0131yor, pop \u015fark\u0131lar her zamankinden daha basit melodiler kullan\u0131yor ve g\u00f6rsel sanatlar daha basit sanat yap\u0131tlar\u0131na kucak a\u00e7\u0131yor: Monet yerini Picasso\u2019ya ve Picasso da Rothko\u2019ya b\u0131rak\u0131yor. \u00c7a\u011f\u0131n d\u00fc\u015f\u00fcncesini, ruhunu yans\u0131tan \u201cDerinlik basitlikte gizlidir\u201d ifadesi, insan v\u00fccuduna dair alg\u0131m\u0131z\u0131 ilgin\u00e7 bi\u00e7imlerde \u015fekillendiriyor. Kalp at\u0131\u015f\u0131 sesi \u00f6rne\u011fin, do\u011fan\u0131n basit ve zarif bir ritmi olarak bize haz verirken; belli bir d\u00fczeyi a\u015fan basitlik, kalp yetmezli\u011finin bir g\u00f6stergesi olarak i\u00e7imize korku salabiliyor.<\/p>\n\n\n\n

Fazla basitli\u011fin sorun oldu\u011fu tek yer kalptir belki de, diye d\u00fc\u015f\u00fcn\u00fcyor olabilirsiniz. Fakat bunu destekleyen ba\u015fka \u00f6rnekler de verebiliriz. N\u00f6rolojiye bakt\u0131\u011f\u0131m\u0131zda, sa\u011fl\u0131kl\u0131 olan bir beynin karma\u015f\u0131k elektriksel \u00f6r\u00fcnt\u00fclere sahip oldu\u011fu g\u00f6r\u00fcl\u00fcrken; epilepsi n\u00f6beti ge\u00e7iren bireylerin beyninde olduk\u00e7a d\u00fczenli elektriksel aktivite g\u00f6zlemlenir. Psikiyatride ise yeni ara\u015ft\u0131rmalar, otizmli bireylerin sa\u011fl\u0131kl\u0131 bireylere k\u0131yasla olduk\u00e7a d\u00fczenli konu\u015fma kal\u0131plar\u0131na sahip oldu\u011funu g\u00f6stermi\u015ftir.<\/p>\n\n\n\n

Hayat karma\u015f\u0131kt\u0131r, ancak karma\u015f\u0131kl\u0131k neden sa\u011fl\u0131kl\u0131d\u0131r? Ve d\u00fczen neden beyinde bir hastal\u0131\u011fa i\u015faret eder?<\/p>\n\n\n\n

\u0130lk olarak 1987’de New York\u2019taki Brookhaven Ulusal Laboratuvar\u0131\u2019ndan Per Bak, Chao Tang ve Kurt Wiesenfeld taraf\u0131ndan tan\u0131mlanan kendi kendini organize eden kritiklik (KKOK, Self-organized criticality) adl\u0131 bir kavram, a\u00e7\u0131klamaya yard\u0131mc\u0131 olur. KKOK teorisini anlamak i\u00e7in sahilde bir kum y\u0131\u011f\u0131n\u0131 tepesi hayal edin. E\u011fer kum y\u0131\u011f\u0131n\u0131na e\u011fimi daha fazla kumu destekleyemeyecek dikli\u011fe gelene kadar kum eklersek, irili ufakl\u0131, farkl\u0131 b\u00fcy\u00fckl\u00fcklerde \u00e7\u0131\u011flar meydana gelir.Bu \u00e7\u0131\u011flar, bir enerji olu\u015fturan yava\u015f bir s\u00fcrecin (kum eklemek) ve bu enerjiyi par\u00e7alayan h\u0131zl\u0131 bir s\u00fcrecin (s\u00fcrt\u00fcnme kuvvetinin \u00fcstesinden gelen yer\u00e7ekimi kuvveti) sonunda meydana gelir. Kum y\u0131\u011f\u0131n\u0131 tepesinin de\u011fi\u015fkenli\u011findeki bu karma\u015f\u0131k durum kritiklik olarak tan\u0131mlan\u0131r. Karma\u015f\u0131k beyin aktivitesinde oldu\u011fu gibi, \u00e7\u0131\u011flar t\u00fcm uzaysal ve mekansal \u00f6l\u00e7eklerde mevcuttur ve sadece sistemin kurucu par\u00e7alar\u0131 incelenerek anla\u015f\u0131lamaz.<\/p>\n\n\n\n

Kum y\u0131\u011f\u0131n\u0131nda oldu\u011fu gibi, beyinde de kritik bir nokta vard\u0131r. Ancak kum y\u0131\u011f\u0131n\u0131nda olu\u015fan \u00e7\u0131\u011flar hi\u00e7bir \u015fekilde anlaml\u0131 bir bilgi i\u015fleme yapmazken, \u20132003 y\u0131l\u0131nda ABD Ulusal Ak\u0131l Sa\u011fl\u0131\u011f\u0131 Enstit\u00fcs\u00fc\u2019nde ara\u015ft\u0131rmac\u0131lar taraf\u0131ndan karma\u015f\u0131k beyin aktivitesi kademeleri olarak tan\u0131mlanan\u2013 n\u00f6ral \u00e7\u0131\u011flar bir\u00e7ok bili\u015fsel durum ve motor i\u015fleyi\u015f aras\u0131nda h\u0131zla ge\u00e7i\u015f yapan bir beyin i\u00e7in hayati \u00f6neme sahip olabilir. Ba\u015fka bir deyi\u015fle, beyin gibi canl\u0131 bir sistemde KKOK bir rahats\u0131zl\u0131k de\u011fil, daha \u00e7ok h\u0131zl\u0131 hesaplamalar i\u00e7in gerekli bir mekanizmad\u0131r. T\u0131pk\u0131 kendi kendini organize etme davran\u0131\u015f\u0131yla finansal piyasalar\u0131n de\u011ferini h\u0131zla \u2018belirleyen\u2019 veya se\u00e7menlerin h\u0131zla politik partiler aras\u0131nda ge\u00e7i\u015f yapmas\u0131n\u0131 sa\u011flayan bir mekanizma gibi. Beyin i\u00e7in bu kritiklik durumunun \u2013ve dolay\u0131s\u0131yla karma\u015f\u0131k davran\u0131\u015f\u0131n\u2013 kayb\u0131 patolojik bir durumdur.<\/p>\n\n\n\n

O halde, elektriksel beyin aktivitesinde g\u00f6zlemlenen karma\u015f\u0131kl\u0131\u011f\u0131n, hastal\u0131k riskini g\u00f6rme veya tan\u0131 koymada yararl\u0131 bir biyobelirteci (biomarker) i\u015flevi g\u00f6rebilmesi \u015fa\u015f\u0131rt\u0131c\u0131 de\u011fildir. Fakat \u015fu noktaya dikkat \u00e7ekmek de fayda var: olduk\u00e7a karma\u015f\u0131k ve hi\u00e7bir d\u00fczene sahip olmayan beyin sinyalleri sa\u011fl\u0131kl\u0131l\u0131k demek de\u011fildir. Karma\u015f\u0131kl\u0131k \u2013daha a\u00e7\u0131k bir ifadeyle\u2013 d\u00fczen ve d\u00fczensizlik veya dura\u011fanl\u0131k (stability) ve de\u011fi\u015fim (instability) durumlar\u0131 gibi kar\u015f\u0131t e\u011filimler aras\u0131ndaki dengedir. D\u00fcnyan\u0131n d\u00f6rt bir yan\u0131ndan \u00f6nde gelen kurumlardaki ara\u015ft\u0131rmac\u0131lar, karma\u015f\u0131kl\u0131\u011f\u0131 \u00f6l\u00e7en matematiksel ara\u00e7lar\u0131 kullanarak kafa derisinden giri\u015fimsel-olmayan (non-invasive) bir y\u00f6ntemle kaydedilen EEG sinyallerinde \u2013otizm ve \u015fizofreni dahil olmak \u00fczere\u2013 psikiyatrik bozukluklar\u0131n potansiyel biyobelirte\u00e7lerini belirlediler. \u00d6rne\u011fin William Bosl ve Boston \u00c7ocuk Hastanesi ve Boston \u00dcniversitesi\u2019ndeki di\u011fer meslekta\u015flar\u0131 umut verici bir \u00e7al\u0131\u015fmada, EEG sinyallerindeki karma\u015f\u0131kl\u0131\u011f\u0131 kullanarak otizm geli\u015ftirme riski olan bebekleri saptad\u0131lar.<\/p>\n\n\n\n

KKOK, karma\u015f\u0131k davran\u0131\u015flar\u0131 a\u00e7\u0131klamak i\u00e7in \u00e7ok soyut bir mekanizma iken, beyin a\u011flar\u0131n\u0131n fiziksel mimarisinde n\u00f6ral karma\u015f\u0131kl\u0131k i\u00e7in daha somut bir a\u00e7\u0131klama bulunabilir. Anatomik beyin b\u00f6lgelerini anatomik a\u011flarla birbirine ba\u011flanm\u0131\u015f Facebook arkada\u015flar\u0131 olarak hayal edin. Sosyal a\u011flarda oldu\u011fu gibi, b\u00f6lgelerin (veya Facebook profillerinin) y\u00fczde 20’si ba\u011flant\u0131lar\u0131n y\u00fczde 80’ini olu\u015fturur. Sosyal a\u011flar gibi beyin b\u00f6lgeleri de yo\u011fun bi\u00e7imde birbirine ba\u011fl\u0131 \u2013daha b\u00fcy\u00fck bir a\u011f\u0131n i\u00e7ine g\u00f6m\u00fcl\u00fc mini a\u011flar\u2013 \u201cgruplar\u201d olu\u015fturur. Bu gruplar genellikle mod\u00fclerlik olarak bilinen daha b\u00fcy\u00fck gruplar\u0131n bir par\u00e7as\u0131d\u0131r. Facebook\u2019ta en yak\u0131n arkada\u015flar\u0131n\u0131z daha b\u00fcy\u00fck, daha geni\u015f bir arkada\u015f grubunun hatta bu grup da bir kasaba veya \u00fcniversite gibi daha da b\u00fcy\u00fck bir toplulu\u011fun bir par\u00e7as\u0131 olabilir. Hem sosyal a\u011flarda hem de beyinlerde par\u00e7alar aras\u0131ndaki karma\u015f\u0131k etkile\u015fim t\u00fcm \u00f6l\u00e7eklerde fenomenler meydana getirir. Hem beyinler hem de sosyal a\u011flar bir \u015fekilde bir kar\u0131nca kolonisine benzer: Organize etkinlikler mekansal \u00f6l\u00e7eklerde ger\u00e7ekle\u015fir ve koloniyi bir b\u00fct\u00fcn olarak kavramak i\u00e7in tek bir kar\u0131nca \u00fczerinde \u00e7al\u0131\u015famazs\u0131n\u0131z.<\/p>\n\n\n\n

Asl\u0131nda, t\u00fcm beyin organizasyonu ve aktivitesi \u00f6l\u00e7eklerinde, \u00f6l\u00e7eksiz da\u011f\u0131t\u0131m bol miktarda bulunur. Kafa derisinden ve korteksten elektriksel aktivite kay\u0131tlar\u0131, sanki ortalama bir frekans yokmu\u015f gibi dalgalan\u0131r. \u00d6l\u00e7eksiz da\u011f\u0131l\u0131m, n\u00f6ral ate\u015fleme (neural spiking) \u2013iyon kanallar\u0131n\u0131n a\u00e7\u0131l\u0131p kapanmas\u0131 ve sinapsta n\u00f6rotransmiter sal\u0131n\u0131m\u0131\u2013 \u00f6l\u00e7\u00fcmlerinde g\u00f6zlenmi\u015ftir.<\/p>\n\n\n\n

Hangi mekanizmalar\u0131n n\u00f6ral karma\u015f\u0131kl\u0131\u011fa ve sa\u011fl\u0131kl\u0131 davran\u0131\u015fa yol a\u00e7t\u0131\u011f\u0131 net olmasa da, karma\u015f\u0131kl\u0131\u011f\u0131 incelemek epilepsi, otizm ve \u015fizofreni gibi beyin bozukluklar\u0131n\u0131 anlamak ve tan\u0131lamak i\u00e7in \u00f6nemlidir. Beyin aktivitesinin karma\u015f\u0131kl\u0131\u011f\u0131n\u0131n \u00f6l\u00e7\u00fclmesi, doktorlar\u0131n yak\u0131nda hangi bebeklerin otizm geli\u015ftirece\u011fini ve \u015fizofreni hastalar\u0131n\u0131n ila\u00e7lara nas\u0131l yan\u0131t verece\u011fini tahmin etmesine olanak sa\u011flayabilir. Fizik\u00e7i Emerson Pugh\u2019un dedi\u011fi gibi: \u201cBeyinlerimiz onlar\u0131 anlayacak kadar basit olsayd\u0131, o kadar basit olurduk ki anlayamazd\u0131k.\u201d<\/p>","protected":false},"featured_media":1831,"template":"","meta":{"_acf_changed":false},"event_publishing_tags":[83,97,98,94,93,378,518,82,691,64,377,92,283,74,284,66,65,75,351,726,100,471],"kategori":[305],"class_list":["post-1830","blog_content","type-blog_content","status-publish","has-post-thumbnail","hentry","event_publishing_tags-beyin","event_publishing_tags-bilim","event_publishing_tags-bilim-felsefesi","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-complexity","event_publishing_tags-felsefe","event_publishing_tags-karmasiklik","event_publishing_tags-neuroscience","event_publishing_tags-norobilim","event_publishing_tags-philosophy","event_publishing_tags-philosophy-of-science","event_publishing_tags-philsci","event_publishing_tags-science","event_publishing_tags-sinirbilim","kategori-ceviri"],"acf":[],"_links":{"self":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/blog_content\/1830","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\/1830\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media\/1831"}],"wp:attachment":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media?parent=1830"}],"wp:term":[{"taxonomy":"event_publishing_tags","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/event_publishing_tags?post=1830"},{"taxonomy":"kategori","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/kategori?post=1830"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}