{"id":1672,"date":"2020-09-22T15:00:00","date_gmt":"2020-09-22T15:00:00","guid":{"rendered":"https:\/\/cog-ist.com\/?post_type=blog_content&p=1672"},"modified":"2025-08-13T20:34:57","modified_gmt":"2025-08-13T20:34:57","slug":"norogoruntuleme-kognitif-vikimaraton","status":"publish","type":"blog_content","link":"https:\/\/cog-ist.com\/en\/blog_content\/norogoruntuleme-kognitif-vikimaraton\/","title":{"rendered":"N\u00f6rog\u00f6r\u00fcnt\u00fcleme \u2014 Kognitif VikiMaraton"},"content":{"rendered":"\n

Bu d\u00f6k\u00fcman 2 Eyl\u00fcl 2020 \u2018de CogIST olarak Vikipedi T\u00fcrkiye\u2019de ger\u00e7ekle\u015ftirdi\u011fimiz katk\u0131lar\u0131n bir ar\u015fivi niteli\u011findedir. Vikipedideki maddeler s\u0131kl\u0131kla de\u011fi\u015ftirilebildi\u011fi i\u00e7in, bu katk\u0131lar\u0131n kendi pay\u0131m\u0131za d\u00fc\u015fen k\u0131sm\u0131n\u0131 belgelemek ve ar\u015fivlemek gere\u011fi duyduk. Bu maddeye <\/em>Vikipedi\u2019de <\/em><\/a>de eri\u015febilirsiniz. T\u00fcm Kognitif VikiMaraton detaylar\u0131na ise <\/em>buradan<\/em><\/a> ula\u015fabilirsiniz.<\/em><\/p>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fcleme veya beyin g\u00f6r\u00fcnt\u00fcleme; sinir sisteminin yap\u0131s\u0131n\u0131, i\u015flevini veya farmakolojisini do\u011frudan veya dolayl\u0131 yollarla g\u00f6r\u00fcnt\u00fclemek i\u00e7in \u00e7e\u015fitli tekniklerin kullan\u0131m\u0131d\u0131r. T\u0131p<\/a>, sinirbilim<\/a> ve psikolojide<\/a> kullan\u0131m\u0131na g\u00f6rece yeni ba\u015flanan bir disiplindir[1]. Klinik ortamda n\u00f6rog\u00f6r\u00fcnt\u00fclemenin yap\u0131lmas\u0131nda ve yorumlanmas\u0131nda g\u00f6revli hekimler de n\u00f6roradyolog olarak adland\u0131r\u0131l\u0131r.<\/p>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fcleme kabaca iki kategoriye ayr\u0131l\u0131r:<\/p>\n\n\n\n

\u00b7 <\/strong>Yap\u0131sal G\u00f6r\u00fcnt\u00fcleme (Structural imaging): Sinir sisteminin yap\u0131s\u0131n\u0131n g\u00f6r\u00fcnt\u00fclenmesi ve kafatas\u0131n\u0131n i\u00e7erisindeki geni\u015f \u00e7apl\u0131 (b\u00fcy\u00fck boyutlarda) hastal\u0131k (t\u00fcm\u00f6r gibi) ve sakatl\u0131klar\u0131n tespiti i\u00e7in ger\u00e7ekle\u015ftirilir.<\/p>\n\n\n\n

\u00b7 \u0130\u015flevsel G\u00f6r\u00fcnt\u00fcleme (Functional imaging): Daha k\u00fc\u00e7\u00fck boyutlardaki metabolik hastal\u0131klar\u0131 ve lezyonlar\u0131 (Alzheimer hastal\u0131\u011f\u0131ndaki gibi) te\u015fhis edebilmede, bili\u015fsel psikoloji<\/a> ara\u015ft\u0131rmalar\u0131nda ve beyin-bilgisayar aray\u00fczleri<\/a> geli\u015ftirmede kullan\u0131l\u0131r. Beyinde ilgili merkezlerin bilgiyi (information) i\u015flemesi s\u00fcrecini direkt olarak g\u00f6r\u00fcnt\u00fcleyebilmemizi sa\u011flar. B\u00f6yle bir i\u015fleme s\u00fcreci, beyinde ilgili b\u00f6lgedeki metabolik aktivitenin artmas\u0131na ve taramada \u201cparlamas\u0131na\u201d sebep olur. N\u00f6rog\u00f6r\u00fcnt\u00fclemenin kullan\u0131ld\u0131\u011f\u0131 alanlara bir ba\u015fka \u00f6rnek de daha tart\u0131\u015fmal\u0131 olan \u201cd\u00fc\u015f\u00fcnce tan\u0131ma\u201d (mind identification) veya \u201czihin-okuma\u201d (mind-reading) alanlar\u0131d\u0131r.<\/p>\n\n\n\n

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\u0130yi huylu makrosefali hastal\u0131\u011f\u0131 olan birine ait kafan\u0131n para-sajital d\u00fczlemden \u00e7ekilen MRI g\u00f6r\u00fcnt\u00fcs\u00fc<\/figcaption><\/figure>\n\n\n\n

Tarih\u00e7e<\/strong><\/h1>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fclemenin tarih\u00e7esi \u0130talyan sinirbilimci Angelo Mosso\u2019nun, duygusal ve entelekt\u00fcel aktiviteler esnas\u0131nda kan\u0131n beyindeki da\u011f\u0131l\u0131m\u0131n\u0131 giri\u015fimsel-olmayan (non-invasive) (cildin b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc bozmayan) \u015fekilde \u00f6l\u00e7en \u201cinsan dola\u015f\u0131m dengesi\u201d aletine kadar uzan\u0131yor[2].<\/p>\n\n\n\n

1918\u2019de Amerikan beyin cerrah\u0131 Walter Dandy, ventrik\u00fclografi isimli bir teknik ortaya \u00e7\u0131kard\u0131. Beyindeki ventrik\u00fcler sistemin X-Ray g\u00f6r\u00fcnt\u00fcleri, filtrelenmi\u015f havan\u0131n beyinde lateralventrik\u00fcllere enjekte edilmesiyle elde edildi. Dandy ayn\u0131 zamanda subaraknoid bo\u015flu\u011fa bel omurundan enjekte edilen havan\u0131n serebralventrik\u00fcllere girebildi\u011fini ve normalde beyin-omurilik s\u0131v\u0131s\u0131 i\u00e7eren b\u00f6lgeleri ortaya \u00e7\u0131kard\u0131\u011f\u0131n\u0131 g\u00f6zlemledi. Bu teknik de pn\u00f6moensefalografi (beyindeki beyin-omurilik s\u0131v\u0131s\u0131n\u0131 bo\u015falt\u0131p yerine hava enjekte ederek X-Ray g\u00f6r\u00fcnt\u00fclerinde beynin daha net g\u00f6z\u00fckmesini sa\u011flayan bir teknik) olarak adland\u0131r\u0131ld\u0131.<\/p>\n\n\n\n

1927\u2019de EgasMoniz, beyindeki hem normal hem abnormal damarlar\u0131 y\u00fcksek e\u015f de\u011ferlikte g\u00f6r\u00fcnt\u00fclemeyi sa\u011flayan beyin anjiyografisi isimli metodu ortaya \u00e7\u0131kard\u0131.<\/p>\n\n\n\n

1970\u2019lerin ba\u015f\u0131nda Allan McLeodCormack ve Godfrey Newbold Hounsfield bilgisayarl\u0131 tomografiyi<\/a> (BT) buldu ve b\u00f6ylece beynin ara\u015ft\u0131rma ve tan\u0131ya y\u00f6nelik \u00e7ok daha detayl\u0131 anatomik g\u00f6r\u00fcnt\u00fcleri elde edilmeye ba\u015fland\u0131. Cormack ve Hounsfield bu teknikle 1979\u2019da Nobel Fizyoloji veya T\u0131p \u00d6d\u00fcl\u00fcn\u00fc kazand\u0131. 1980\u2019lerin ba\u015f\u0131nda radyoligandlar\u0131n geli\u015ftirilmesiyle tek-foton emisyonlu bilgisayarl\u0131 tomografi ve pozitron emisyon tomografisi<\/a> gibi teknikler ortaya \u00e7\u0131kar\u0131ld\u0131.<\/p>\n\n\n\n

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Kafatas\u0131n\u0131n \u00fcst\u00fcnden alt\u0131na do\u011fru bir bilgisayarl\u0131 tomografi \u00f6rne\u011fi<\/figcaption><\/figure>\n\n\n\n

Yakla\u015f\u0131k ayn\u0131 zamanlarda Peter Mansfield ve Paul Lauterbur gibi ara\u015ft\u0131rmac\u0131lar taraf\u0131ndan manyetik rezonans g\u00f6r\u00fcnt\u00fcleme tekni\u011fi (MRI veya MR taramas\u0131) geli\u015ftirildi ve bu teknik 2003\u2019te Nobel Fizyoloji veya T\u0131p \u00d6d\u00fcl\u00fcne lay\u0131k g\u00f6r\u00fcld\u00fc. 1980\u2019lerin ba\u015f\u0131nda MRI klinikte kullan\u0131lmaya ba\u015fland\u0131 ve 1980\u2019ler boyunca tekni\u011fe baz\u0131 d\u00fczeltmeler ve tan\u0131sal MR uygulamalar\u0131 getirildi. Bilim insanlar\u0131 daha sonra PET\u2019le \u00f6l\u00e7\u00fclen kan ak\u0131\u015f\u0131ndaki b\u00fcy\u00fck de\u011fi\u015fimlerin ayn\u0131 zamanda do\u011fru tipteki bir MRI tekni\u011fi ile \u00f6l\u00e7\u00fclebilece\u011fini \u00f6\u011frendi. Bu \u015fekilde i\u015flevsel (fonksiyonel) manyetik rezonans g\u00f6r\u00fcnt\u00fcleme (fMRI) do\u011fdu ve 1990\u2019lardan beri fMRI d\u00fc\u015f\u00fck giri\u015fimselli\u011fi (invasiveness), ki\u015fiyi radyasyona maruz b\u0131rakmamas\u0131 ve g\u00f6rece yayg\u0131n eri\u015filebilirli\u011fiyle beyin g\u00f6r\u00fcnt\u00fcleme ve haritalama alan\u0131n\u0131 domine etmektedir.<\/p>\n\n\n\n

2000\u2019lerin ba\u015f\u0131nda n\u00f6rog\u00f6r\u00fcnt\u00fcleme alan\u0131, i\u015flevsel beyin g\u00f6r\u00fcnt\u00fclemenin baz\u0131 pratik uygulamalar\u0131n\u0131n ger\u00e7ekle\u015ftirilebilece\u011fi bir noktaya eri\u015fti. Bu ba\u011flamda ana uygulama alan\u0131 hen\u00fcz basit formlardaki beyin-bilgisayar aray\u00fczleri<\/a>dir.<\/p>\n\n\n\n

Klinikte Kullan\u0131ld\u0131\u011f\u0131 Durumlar<\/h1>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fcleme, hekimin n\u00f6rolojik muayene sonucunda sinirsel bir hastal\u0131\u011f\u0131 olan veya olmas\u0131ndan \u015f\u00fcphelenilen bir hastay\u0131 daha detayl\u0131 incelemeye gerek duymas\u0131n\u0131 halinde kullan\u0131l\u0131r.<\/p>\n\n\n\n

Ki\u015filerin tecr\u00fcbe edebilece\u011fi yayg\u0131n sinirsel problemlerden biri de bay\u0131lmad\u0131r[3][4]. Bu durumda hastan\u0131n ge\u00e7mi\u015fi sinirsel semptomlara i\u015faret etmiyorsa te\u015fhiste n\u00f6rolojik muayene kullan\u0131l\u0131r fakat rutin n\u00f6rog\u00f6r\u00fcnt\u00fclemeye gerek duyulmaz \u00e7\u00fcnk\u00fc bu durumlarda bay\u0131lma sebebinin merkezi sinir sisteminde bulunma ihtimali son derece d\u00fc\u015f\u00fckt\u00fcr ve hasta b\u00fcy\u00fck ihtimalle n\u00f6rog\u00f6r\u00fcnt\u00fcleme prosed\u00fcr\u00fcn\u00fcn yarar\u0131n\u0131 g\u00f6rmeyecektir[4].<\/p>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fcleme s\u00fcrekli ba\u015f a\u011fr\u0131s\u0131 olan ve migren tan\u0131s\u0131 konmu\u015f hastalar i\u00e7in de \u00f6nerilmez[5]. \u00c7al\u0131\u015fmalar migrenin hastalarda intrakraniyal (intracranial) hastal\u0131k riskini art\u0131rmad\u0131\u011f\u0131n\u0131 ve papil \u00f6demi gibi di\u011fer problemler olmadan migren te\u015fhisi konulan hastalarda n\u00f6rog\u00f6r\u00fcnt\u00fclemenin gerekli olmad\u0131\u011f\u0131n\u0131 g\u00f6stermektedir. [5]. Bununla birlikte hekim, \u00f6zenli bir tan\u0131 s\u00fcrecinde ba\u015f a\u011fr\u0131s\u0131n\u0131n migren d\u0131\u015f\u0131nda bir sebebi olup olmad\u0131\u011f\u0131n\u0131 ve varsa n\u00f6rog\u00f6r\u00fcnt\u00fclemenin gerekebilece\u011fini dikkate almal\u0131d\u0131r[5].<\/p>\n\n\n\n

\u0130ntrakraniyal t\u00fcm\u00f6rler, arteriy\u00f6ven\u00f6z anomaliler ve ameliyatla tedavi edilebilecek di\u011fer durumlarda BT, MRI ve PET rehberli\u011finde yap\u0131lan stereotaktik ameliyatlar, n\u00f6rog\u00f6r\u00fcnt\u00fclemenin kullan\u0131m\u0131n\u0131 gerektiren bir di\u011fer aland\u0131r[6][7][8][9].<\/p>\n\n\n\n

Beyin G\u00f6r\u00fcnt\u00fcleme Teknikleri<\/h1>\n\n\n\n

Bilgisayarl\u0131 Aksiyal Tomografi (Computed Axial Tomography)<\/strong><\/p>\n\n\n\n

Bilgisayarl\u0131 tomografi (BT) ya da bilgisayarl\u0131 aksiyal tomografi (BAT), kafaya \u00e7ok say\u0131da farkl\u0131 a\u00e7\u0131dan X-Ray \u0131\u015f\u0131nlar\u0131n\u0131n g\u00f6nderildi\u011fi bir tarama tekni\u011fidir. Yayg\u0131n olarak beyindeki zedelenmeleri h\u0131zl\u0131ca g\u00f6r\u00fcnt\u00fclemek i\u00e7in kullan\u0131l\u0131r. BT taramalar\u0131, beynin k\u00fc\u00e7\u00fck bir k\u0131sm\u0131nda bir X-Ray \u0131\u015f\u0131n\u0131n\u0131n ne kadar\u0131n\u0131n so\u011furuldu\u011funu bulmak i\u00e7in say\u0131sal integral hesaplamalar\u0131 (ters Radon d\u00f6n\u00fc\u015f\u00fcm\u00fc gibi) yapan bir bilgisayar program\u0131 kullan\u0131r. Bu bilgi yayg\u0131n olarak beyin kesitlerine ait g\u00f6r\u00fcnt\u00fclerin elde edilmesi i\u00e7in kullan\u0131l\u0131r[10].<\/p>\n\n\n\n

Da\u011f\u0131n\u0131k Optik G\u00f6r\u00fcnt\u00fcleme (Diffuse Optical Imaging)<\/strong><\/p>\n\n\n\n

Da\u011f\u0131n\u0131k optik g\u00f6r\u00fcnt\u00fcleme veya da\u011f\u0131n\u0131k optik tomografi, v\u00fccuda ait g\u00f6r\u00fcnt\u00fcler olu\u015fturmak i\u00e7in k\u0131z\u0131l\u00f6tesine yak\u0131n dalgaboylar\u0131nda \u0131\u015f\u0131k kullanan bir medikal g\u00f6r\u00fcnt\u00fcleme tekni\u011fidir. Hemoglobinin<\/a> optik so\u011furmas\u0131n\u0131 \u00f6l\u00e7en bu teknik, hemoglobinin so\u011furma spektrumunun oksijene ba\u011fl\u0131 olup olmamas\u0131na ba\u011fl\u0131 olarak de\u011fi\u015fmesini kullan\u0131r. Y\u00fcksek yo\u011funluklu da\u011f\u0131n\u0131k optik g\u00f6r\u00fcnt\u00fcleme (HD-DOT) ile i\u015flevsel manyetik rezonans g\u00f6r\u00fcnt\u00fcleme, iki teknikle de incelenen deneklerin g\u00f6rsel uyaranlara verdikleri tepkilerle ilgili bir \u00e7al\u0131\u015fmada kar\u015f\u0131la\u015ft\u0131r\u0131lm\u0131\u015f ve g\u00fcven verici \u00f6l\u00e7\u00fcde benzer sonu\u00e7lar elde edilmi\u015ftir[11]. HD-DOT ayn\u0131 zamanda fMRI ile dil ile ilgili g\u00f6revler ve dinlenme an\u0131ndaki i\u015flevsel ba\u011flant\u0131sall\u0131k konular\u0131nda da kar\u015f\u0131la\u015ft\u0131r\u0131lm\u0131\u015f durumda[12].<\/p>\n\n\n\n

Olaya Ba\u011fl\u0131 Optik Sinyal (Event-related Optical Signal)<\/strong><\/p>\n\n\n\n

Olaya-ba\u011fl\u0131 Optik Sinyal, optik fiberler arac\u0131l\u0131\u011f\u0131yla k\u0131z\u0131l\u00f6tesi \u0131\u015f\u0131nlar yollayarak serebral korteksteki aktif b\u00f6lgelerin optik \u00f6zelliklerindeki de\u011fi\u015fimleri \u00f6l\u00e7en bir beyin tarama tekni\u011fidir. Da\u011f\u0131n\u0131k optik g\u00f6r\u00fcnt\u00fcleme hemoglobinin optik so\u011furmas\u0131n\u0131 \u00f6l\u00e7t\u00fc\u011f\u00fc i\u00e7in kan ak\u0131\u015f\u0131na ba\u011fl\u0131 bir teknikken olaya ba\u011fl\u0131 optik sinyal direkt olarak n\u00f6ronlar\u0131n aktif haldeyken \u0131\u015f\u0131\u011f\u0131 sa\u00e7mas\u0131nda meydana gelen de\u011fi\u015fikliklerden faydalan\u0131r; b\u00f6ylece h\u00fccresel aktivitenin daha isabetli \u00f6l\u00e7\u00fcm\u00fcn\u00fc sa\u011flar. Bu teknik beyinde ger\u00e7ekle\u015fen aktivitelerin lokasyonunu milimetreler d\u00fczeyinde, zaman\u0131n\u0131 da milisaniyeler d\u00fczeyinde bir \u00e7\u00f6z\u00fcn\u00fcrl\u00fckle tespit eder. Tekni\u011fin en b\u00fcy\u00fck problemi ise kafatas\u0131ndan en fazla birka\u00e7 santimetre derinli\u011finde \u00f6l\u00e7\u00fcm yapabilmesidir. G\u00f6rece yeni, ucuz ve giri\u015fimselci-olmayan bir tekniktir. Urbana-Champaign\u2019deki Illinois \u00dcniversitesinde geli\u015ftirilmi\u015f olup buradaki Bili\u015fsel N\u00f6rog\u00f6r\u00fcnt\u00fcleme Laboratuvar\u0131nda Dr. GabrieleGratton ve Dr. Monica Fabiani taraf\u0131ndan kullan\u0131lmaktad\u0131r.<\/p>\n\n\n\n

Manyetik Rezonans G\u00f6r\u00fcnt\u00fcleme (Magnetic Resonance Imaging)<\/strong><\/p>\n\n\n\n

Manyetik rezonans g\u00f6r\u00fcnt\u00fcleme, iyonize edici radyasyon ve radyoaktif izleyiciler olmadan beyin yap\u0131lar\u0131n\u0131n y\u00fcksek kalitede iki veya \u00fc\u00e7 boyutlu g\u00f6r\u00fcnt\u00fclerini olu\u015fturmak i\u00e7in manyetik alanlar ve radyo dalgalar\u0131 kullan\u0131r.<\/p>\n\n\n\n

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Sajital d\u00fczlemde iki hemisferin tam orta \u00e7izgisinden al\u0131nan bir MRI kesiti<\/figcaption><\/figure>\n\n\n\n

\u0130\u015flevsel Manyetik Rezonans G\u00f6r\u00fcnt\u00fcleme (Functional Magnetic Resonance Imaging)<\/strong><\/p>\n\n\n\n

Fonksiyonel manyetik rezonans g\u00f6r\u00fcnt\u00fcleme (fMRI) ve arteriyelspin etiketleme teknikleri, beyinde sinirsel aktiviteye ba\u011fl\u0131 olarak de\u011fi\u015fen kan ak\u0131\u015f\u0131n\u0131n\u0131 g\u00f6r\u00fcnt\u00fcleyebilmek i\u00e7in oksijene ba\u011flanm\u0131\u015f ve ba\u011flanmam\u0131\u015f hemoglobinin paramanyetik \u00f6zelliklerinden faydalan\u0131r. Bu da dinlenme durumunda veya \u00e7e\u015fitli g\u00f6revlerin ger\u00e7ekle\u015ftirilmesi s\u0131ras\u0131nda hangi beyin b\u00f6lgelerinin aktifle\u015fti\u011fini (ve nas\u0131l aktifle\u015ftiklerini) g\u00f6r\u00fcnt\u00fclemeyi sa\u011flar. Oksijen durumu (oxygenation) hipotezine g\u00f6re bili\u015fsel veya davran\u0131\u015fsal aktiviteler s\u0131ras\u0131nda hangi b\u00f6lgelerdeki kan ak\u0131\u015f\u0131nda oksijen miktar\u0131nda de\u011fi\u015fim g\u00f6zleniyorsa, o b\u00f6lgeler o s\u0131radaki aktiviteyle direkt olarak ili\u015fkilendirilebilir.<\/p>\n\n\n\n

\u00c7o\u011fu fMRI taray\u0131c\u0131s\u0131 deneklere farkl\u0131 g\u00f6rsel, i\u015fitsel veya dokunsal uyaranlar verilebilmesine ve bir tu\u015fa basmak veya oyun konsolunu hareket ettirmek gibi farkl\u0131 hareketleri yapabilmelerine olanak tan\u0131yor. Sonu\u00e7 olarak fMRI; alg\u0131, d\u00fc\u015f\u00fcnce ve hareketle ili\u015fkili beyin yap\u0131lar\u0131n\u0131 ve s\u00fcre\u00e7leri ortaya \u00e7\u0131karmak i\u00e7in kullan\u0131labiliyor. fMRI\u2019\u0131n \u015fu anki \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc 2\u20133 milimetre ve bu s\u0131n\u0131r sinirsel aktiviteye ba\u011fl\u0131 olu\u015fan hemodinamik tepkinin uzamsal yay\u0131lma g\u00f6stermesinden ( ve hemoglobinin oksijene ba\u011fl\u0131l\u0131k oran\u0131n\u0131n sadece aktif h\u00fccrenin oldu\u011fu noktalarda de\u011fil, \u00e7evre b\u00f6lgelerde de de\u011fi\u015fmesinden) kaynaklan\u0131yor. Beyindeki aktivite \u00f6r\u00fcnt\u00fclerinin incelenmesinde fMRI, PET y\u00f6nteminin yerini alm\u0131\u015f durumda. Fakat PET; radyoaktif izleyiciyle i\u015faretlenmi\u015f resept\u00f6r<\/a>ligandlar\u0131n\u0131 (resept\u00f6r ligand\u0131, bir resept\u00f6re ba\u011flanan herhangi bir kimyasald\u0131r) kullanarak beyinde belirli n\u00f6rotransmiterlere ba\u011flanan ilgili resept\u00f6rleri tespit edebilmesi avantaj\u0131na sahip.<\/p>\n\n\n\n

Sa\u011fl\u0131kl\u0131 bireylerle yap\u0131lan ara\u015ft\u0131rmalar\u0131n yan\u0131 s\u0131ra, hastal\u0131k te\u015fhisinde de fMRI giderek daha fazla kullan\u0131l\u0131yor. fMRI kan ak\u0131\u015f\u0131ndaki oksijen seviyesine olduk\u00e7a hassas oldu\u011fundan, beyinde iskemi (dokuya giden kan miktar\u0131n\u0131n a\u015f\u0131r\u0131 d\u00fc\u015f\u00fck olmas\u0131 durumu) veya inme sonucu meydana gelen erken de\u011fi\u015fikliklere de son derece duyarl\u0131. Baz\u0131 inme t\u00fcrlerinde p\u0131ht\u0131lar\u0131 da\u011f\u0131tacak maddeler ilk birka\u00e7 saatte kullan\u0131labilirken, sonras\u0131nda bu maddelerin kullan\u0131m\u0131 tehlikeli olmaya ba\u015fl\u0131yor. Dolay\u0131s\u0131yla n\u00f6rolojide inmenin belli t\u00fcrlerinin erken te\u015fhisi \u00f6nem kazan\u0131yor. fMRI\u2019da g\u00f6r\u00fclen de\u011fi\u015fimler, bu maddelerle tedavi uygulay\u0131p uygulamama karar\u0131na yard\u0131mc\u0131 olabiliyor. Ayr\u0131ca fMRI teknikleri, dene\u011fin belli bir anda bir g\u00f6r\u00fcnt\u00fc setinden hangisini g\u00f6rd\u00fc\u011f\u00fcn\u00fc[14] %72 il\u00e2 %90 aras\u0131ndaki bir e\u015fde\u011ferlikle tahmin edebiliyor (ayn\u0131 tahminin \u015fansla do\u011fru \u00e7\u0131kmas\u0131 ihtimali %0.8[13]).<\/p>\n\n\n\n

\"\"\/
\u00d6rnek FMRI g\u00f6r\u00fcnt\u00fcs\u00fc.<\/figcaption><\/figure>\n\n\n\n

Manyetoensefalografi<\/strong><\/p>\n\n\n\n

Manyetoensefalografi (MEG), S\u00fcperiletken Kuantum Giri\u015fim Cihaz\u0131 (SQUID)<\/a>gibi[15]m\u0131knat\u0131s \u00f6l\u00e7erlerle beyinde elektriksel aktivite sonucu olu\u015fan manyetik alanlar\u0131 \u00f6l\u00e7en bir g\u00f6r\u00fcnt\u00fcleme tekni\u011fidir. MEG; fMRI\u2019a k\u0131yasla n\u00f6ronlardaki elektriksel aktiviteyi \u00e7ok daha direkt olarak \u00f6l\u00e7er, y\u00fcksek zamansal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011fe fakat d\u00fc\u015f\u00fck uzamsal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011fe sahiptir. Sinirsel aktivite sonucu \u00fcretilen manyetik alanlar\u0131 \u00f6l\u00e7menin avantaj\u0131, manyetik alanlar\u0131n elektroensefalografide (EEG)<\/a> \u00f6l\u00e7\u00fclen elektrik alanlar\u0131n aksine \u00e7evre dokulardan (\u00f6zellikle kafa derisi ve kafatas\u0131) daha az etkilenmesidir. Spesifik olarak elektriksel aktivite sonucu \u00fcretilen manyetik alanlar\u0131n \u00e7evredeki kafa dokusundan etkilenmedi\u011fi, kafan\u0131n her biri homojen ve izotropik (y\u00f6nba\u011f\u0131ms\u0131z) iletkenler olan i\u00e7 i\u00e7e ge\u00e7mi\u015f k\u00fcresel kabuklar olarak modellenmesiyle g\u00f6sterilebilir. Fakat ger\u00e7ek kafalar k\u00fcresel de\u011fildir ve (\u00f6zellikle beyaz madde ve kafatas\u0131n\u0131n) iletkenlikleri b\u00fcy\u00fck \u00f6l\u00e7\u00fcde anizotropiktir. Kafatas\u0131 anizotropisinin MEG\u2019ye olan etkisi ihmal edilebilir \u00f6l\u00e7\u00fcdeyken (EEG\u2019nin aksine), beyaz madde anizotropisininbeynin derin b\u00f6lgelerindeki kaynaklardan yap\u0131lan MEG \u00f6l\u00e7\u00fcmlerini \u00f6nemli \u00f6l\u00e7\u00fcde etkiledi\u011fi bulunmu\u015ftur[16]. Fakat bu \u00e7al\u0131\u015fmada kafan\u0131n da homojen bir bi\u00e7imde anizotropik oldu\u011fu varsay\u0131lm\u0131\u015ft\u0131r ki bu ger\u00e7ek kafalar i\u00e7in do\u011fru de\u011fildir. Dolay\u0131s\u0131yla MEG\u2019nin kafatas\u0131 anizotropisinden de etkilenmesi olas\u0131d\u0131r[17], fakat bu etki EEG\u2019deki kadar y\u00fcksek de\u011fildir.<\/p>\n\n\n\n

MEG\u2019nin; bir hastal\u0131\u011f\u0131 lokalize etmede cerrahlara, beyinde belli yolaklar\u0131n i\u015flevini belirlemede de ara\u015ft\u0131rmac\u0131lara yard\u0131mc\u0131 olmas\u0131 gibi bir\u00e7ok kullan\u0131m alan\u0131 vard\u0131r.<\/p>\n\n\n\n

Pozitron Emisyon Tomografisi<\/strong><\/p>\n\n\n\n

Pozitron Emisyon Tomografisi (PET), kana enjekte edilen radyoaktif olarak i\u015faretlenmi\u015f ve metabolik olarak aktif kimyasallardan yay\u0131lan radyasyonu \u00f6l\u00e7er. \u00d6l\u00e7\u00fclen emisyon verileri bilgisayar taraf\u0131ndan bu kimyasallar\u0131n beyindeki da\u011f\u0131l\u0131m\u0131na ait 2 veya 3 boyutlu g\u00f6r\u00fcnt\u00fcler olu\u015fturacak bi\u00e7imde i\u015flenir[18]:57. Pozitron yayan radyoizotoplar bir t\u00fcrpar\u00e7ac\u0131k h\u0131zland\u0131r\u0131c\u0131da<\/a> (kiklotron) \u00fcretilir ve kimyasallar bu radyoaktif atomlarla i\u015faretlenir. Radyoaktif i\u015faretleyici olarak adland\u0131r\u0131lan bu bile\u015fik damardan enjekte edilir ve beyne ula\u015f\u0131r. PET taray\u0131c\u0131lar\u0131ndaki sens\u00f6rler, i\u015faretleyici madde beynin \u00e7e\u015fitli b\u00f6lgelerinde birikirken o b\u00f6lgelerdeki radyoaktiviteyi \u00f6l\u00e7er. Bir bilgisayar, sens\u00f6rler taraf\u0131ndan toplanan verileri kullanarak, ilgili maddenin beynin hangi b\u00f6lgeleri taraf\u0131ndan kullan\u0131ld\u0131\u011f\u0131n\u0131 g\u00f6steren 2 veya 3 boyutlu renklendirilmi\u015f g\u00f6r\u00fcnt\u00fcler olu\u015fturur. \u00d6zellikle n\u00f6rotransmitter<\/a> aktivitesinin farkl\u0131 y\u00f6nlerini haritalamak i\u00e7in kullan\u0131lan ligandlar<\/a> olduk\u00e7a kullan\u0131\u015fl\u0131 olmakla beraber, PET\u2019te en yayg\u0131n olarak kullan\u0131lan i\u015faretleyici, glikozun i\u015faretlenmi\u015f bir formu olan Fludeoxyglucose\u2019dur.<\/p>\n\n\n\n

PET taramas\u0131n\u0131n en b\u00fcy\u00fck avantaj\u0131; farkl\u0131 bile\u015fiklerin \u00e7al\u0131\u015fan beyinde kan ak\u0131\u015f\u0131n\u0131, oksijen seviyesini ve glikoz metabolizmas\u0131n\u0131 g\u00f6sterebilmesidir. Bu \u00f6l\u00e7\u00fcmler beynin \u00e7e\u015fitli b\u00f6lgelerindeki aktivite miktar\u0131n\u0131 yans\u0131t\u0131r ve beynin nas\u0131l \u00e7al\u0131\u015ft\u0131\u011f\u0131 hakk\u0131nda daha fazla \u015fey \u00f6\u011frenmeyi sa\u011flar. PET taramalar\u0131 piyasaya ilk \u00e7\u0131kt\u0131\u011f\u0131nda, uzamsal \u00e7\u00f6z\u00fcn\u00fcrl\u00fck ve tamamlanma s\u00fcresi bak\u0131m\u0131ndan (30 saniye gibi az bir s\u00fcre) di\u011fer t\u00fcm metabolik g\u00f6r\u00fcnt\u00fcleme y\u00f6ntemlerinden \u00fcst\u00fcnd\u00fc. Uzamsal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fcn geli\u015fmesi, belirli bir g\u00f6rev esnas\u0131nda beynin hangi b\u00f6lgelerinin aktifle\u015fti\u011fi konusunda daha iyi \u00e7al\u0131\u015fmalar\u0131n yap\u0131lmas\u0131n\u0131 sa\u011flad\u0131. PET taramas\u0131n\u0131n en b\u00fcy\u00fck sorunu, radyoaktivite h\u0131zl\u0131ca azald\u0131\u011f\u0131 i\u00e7in ancak k\u0131sa s\u00fcreli g\u00f6revlerin incelenebilmesiydi[18]:60. fMRI teknolojisinden \u00f6nce PET, i\u015flevsel beyin g\u00f6r\u00fcnt\u00fcleme (yap\u0131sal g\u00f6r\u00fcnt\u00fclemenin aksine) i\u00e7in tercih edilmekteydi ve bug\u00fcn de sinirbilime b\u00fcy\u00fck katk\u0131lar sa\u011flamaya devam ediyor.<\/p>\n\n\n\n

PET taramalar\u0131 beyin hastal\u0131klar\u0131n\u0131n te\u015fhisinde de kullan\u0131lmaktad\u0131r. Bunun en \u00f6nemli sebebi demans hastal\u0131klar\u0131na (Alzheimer gibi) yol a\u00e7an beyin t\u00fcm\u00f6rleri, inmeler ve n\u00f6ronlara zarar veren hastal\u0131klar\u0131n hepsinin beyin metabolizmas\u0131nda ciddi, dolay\u0131s\u0131yla PET taramalar\u0131nda kolayca g\u00f6r\u00fclebilen de\u011fi\u015fimlere sebep olmas\u0131. PET taramas\u0131n\u0131n muhtemelen en kullan\u0131\u015fl\u0131 oldu\u011fu evreler, belli baz\u0131 demans hastal\u0131klar\u0131n\u0131n (Alzheimer ve Pick<\/a> hastal\u0131klar\u0131 gibi) erken evreleridir. Bunun sebebi de erken evredeki hasar\u0131n beyinde fazla da\u011f\u0131lm\u0131\u015f olmas\u0131, beyin hacmi ve kaba yap\u0131s\u0131nda \u00e7ok az de\u011fi\u015fime yol a\u00e7mas\u0131 ve bu tarz hasarlar\u0131n BT veya MRI g\u00f6r\u00fcnt\u00fclerinde kortikalatrofinin (k\u00f6relme) \u201cnormal\u201d miktarlar\u0131ndan, yani ya\u015flanmayla olu\u015fan fakat klinik demans hastal\u0131klar\u0131na yol a\u00e7mayan durumdan ay\u0131rt edilememesidir.<\/p>\n\n\n\n

Tek-Foton Emisyon Bilgisayarl\u0131 Tomografisi (Single-photon Emission Computed Tomography)<\/strong><\/p>\n\n\n\n

Tek-foton emisyon BT (SPECT), PET\u2019e benzer bir y\u00f6nteme sahiptir.Gama \u0131\u015f\u0131n\u0131 yayan radyoizotoplar ile bir bilgisayar\u0131n beynin aktif b\u00f6lgelerine ait 2 veya 3 boyutlu g\u00f6r\u00fcnt\u00fcler olu\u015fturmak i\u00e7in kulland\u0131\u011f\u0131 verileri kaydeden gamma kameras\u0131 kullan\u0131r. [19]. SPECT, bir radyoaktif i\u015faretleyicinin enjeksiyonuna dayan\u0131r ve bu madde beyin taraf\u0131ndan h\u0131zl\u0131ca al\u0131n\u0131r fakat tekrar da\u011f\u0131t\u0131lmaz. SPECT i\u015faretleyicisinin beyin taraf\u0131ndan al\u0131nmas\u0131, enjeksiyon an\u0131nda serebral dola\u015f\u0131ma<\/a> ba\u011fl\u0131 olarak 30 il\u00e2 60 saniyede tamamlan\u0131r. Bu da SPECT\u2019i, normalde hastalar\u0131n hareket etmeleri ve n\u00f6bet tiplerinin \u00e7e\u015fitlili\u011fi nedeniyle zor yap\u0131labilen epilepsi g\u00f6r\u00fcnt\u00fclemelerine uygun k\u0131lar. Radyoaktif i\u015faretleyici n\u00f6bet esnas\u0131nda enjekte edildi\u011fi s\u00fcrece SPECT, kan ak\u0131\u015f\u0131n\u0131n epilepsi an\u0131ndaki g\u00f6r\u00fcnt\u00fcs\u00fcn\u00fc verir. SPECT\u2019in \u00f6nemli bir sorunu, MRI\u2019a g\u00f6re d\u00fc\u015f\u00fck olan uzamsal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fcd\u00fcr (yakla\u015f\u0131k 1 cm). G\u00fcn\u00fcm\u00fczde ikili dedekt\u00f6r ba\u015fl\u0131\u011f\u0131 olan SPECT makineleri yayg\u0131n olarak kullan\u0131lmaktad\u0131r. Beyin yap\u0131s\u0131n\u0131n tomografik olarak yeniden in\u015fas\u0131 (\u00e7o\u011funlukla beynin anl\u0131k i\u015flevsel foto\u011fraflar\u0131n\u0131 elde etmek i\u00e7in), kafatas\u0131n\u0131n etraf\u0131nda d\u00f6nen dedekt\u00f6r ba\u015fl\u0131klar\u0131ndan \u00e7\u0131kan \u00e7oklu projeksiyonlara ihtiya\u00e7 duyar. Baz\u0131 ara\u015ft\u0131rmac\u0131lar \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc art\u0131r\u0131p g\u00f6r\u00fcnt\u00fcleme i\u00e7in gereken zaman\u0131 azaltmak ad\u0131na 6 il\u00e2 11 tane dedekt\u00f6r ba\u015fl\u0131\u011f\u0131 i\u00e7eren SPECT makineleri geli\u015ftirmi\u015ftir. [20][21].<\/p>\n\n\n\n

SPECT de PET gibi, demans hastal\u0131\u011f\u0131na yol a\u00e7an \u00e7e\u015fitli s\u00fcre\u00e7leri ay\u0131rt etme amac\u0131yla giderek daha fazla kullan\u0131lmaktad\u0131r. PET, FDG gibi yar\u0131-\u00f6mr\u00fc en fazla 110 dakika olan i\u015faretleyicileri kullanmak durumundad\u0131r ve bunlar par\u00e7ac\u0131k h\u0131zland\u0131r\u0131c\u0131larda \u00fcretilebildi\u011finden olduk\u00e7a pahal\u0131 olup PET\u2019in ger\u00e7ekle\u015ftirilece\u011fi yere ula\u015ft\u0131r\u0131lma s\u00fcreleri birka\u00e7 yar\u0131-\u00f6mr\u00fc ge\u00e7erse kullan\u0131lmalar\u0131 m\u00fcmk\u00fcn de\u011fildir. \u00d6te yandan SPECT, yar\u0131-\u00f6mr\u00fc \u00e7ok daha uzun i\u015faretleyicilerden (technetium-99m gibi) faydalanabilir ve sonu\u00e7 olarak kullan\u0131ma \u00e7ok daha elveri\u015flidir.<\/p>\n\n\n\n

N\u00f6rog\u00f6r\u00fcnt\u00fcleme Tekniklerinin Avantajlar\u0131 ve Bu Teknikler Hakk\u0131ndaki Endi\u015feler<\/h1>\n\n\n\n

\u0130\u015flevsel Manyetik Rezonans G\u00f6r\u00fcnt\u00fcleme (fMRI)<\/strong><\/p>\n\n\n\n

fMRI, di\u011fer tekniklere g\u00f6re giri\u015fimsel-olmayan bir teknik oldu\u011fu i\u00e7in az il\u00e2 orta derecede riskli olarak s\u0131n\u0131fland\u0131r\u0131l\u0131r. fMRI, g\u00f6r\u00fcnt\u00fcleme i\u00e7in kandaki oksijen seviyesine ba\u011fl\u0131 (blood oxygenation level dependent \u2014 BOLD) kontrast\u0131 kullan\u0131r. BOLD kontrast\u0131 v\u00fccutta do\u011fal olarak olu\u015fur, bu y\u00fczden de benzer g\u00f6r\u00fcnt\u00fcler elde etmek i\u00e7in radyoaktif i\u015faretleyicilere ihtiya\u00e7 duyan di\u011fer tekniklere g\u00f6re \u00e7o\u011funlukla tercih edilir[22].fMRI\u2019\u0131n kullan\u0131m\u0131 hakk\u0131nda bir endi\u015fe, v\u00fccudunda protez, implant gibi metalik objeler bulunan ki\u015filerde uygulanma durumudur. Bu objelerden yay\u0131lan manyetik rezonans (MR) , t\u0131bbi cihazlar\u0131n bozulmas\u0131na ve v\u00fccuda ba\u015fka metallerin \u00e7ekilmesine sebep olabilir. FDA<\/a>, g\u00fcn\u00fcm\u00fczde t\u0131bbi implant ve cihazlar\u0131 MR\u2019a uygunlu\u011funa g\u00f6re; MR i\u00e7in g\u00fcvenli, MR i\u00e7in g\u00fcvenli de\u011fil ve duruma g\u00f6re g\u00fcvenli olarak \u00fc\u00e7 kategori sunar.[23].<\/p>\n\n\n\n

Bilgisayarl\u0131 Tomografi (BT) Taramalar\u0131<\/strong><\/p>\n\n\n\n

BT, 1970\u2019lerde piyasaya \u00e7\u0131kar\u0131lm\u0131\u015ft\u0131r ve h\u0131zl\u0131ca en \u00e7ok kullan\u0131lan g\u00f6r\u00fcnt\u00fcleme tekniklerinden biri haline gelmi\u015ftir. BT taramas\u0131 bir saniyenin alt\u0131nda ger\u00e7ekle\u015ftirilebilir ve klinisyenler i\u00e7in h\u0131zl\u0131 sonu\u00e7lar sunar. Klinisyenler \u00e7o\u011funlukla birden fazla BT taramas\u0131 al\u0131rlar; BT taramas\u0131 istenen hastalar\u0131n y\u00fczde 30\u2019u bir seferde en az 3 taramaya girer[25]. BT taramalar\u0131, hastalar\u0131 geleneksek X-Ray \u0131\u015f\u0131nlar\u0131na g\u00f6re 100 il\u00e2 500 kat daha fazla radyasyona maruz b\u0131rak\u0131r; radyasyon miktar\u0131 artt\u0131k\u00e7a daha y\u00fcksek \u00e7\u00f6z\u00fcn\u00fcrl\u00fckl\u00fc g\u00f6r\u00fcnt\u00fcler elde edilir [26]. Kullan\u0131m\u0131 basit olmakla beraber \u00f6zellikle semptom g\u00f6stermeyen hastalarda BT kullan\u0131m\u0131, y\u00fcksek miktarda radyasyon sebebiyle bir endi\u015fe konusudur[25].<\/p>\n\n\n\n

Pozitron Emisyon Tomografisi (PET)<\/strong><\/p>\n\n\n\n

PET taramalar\u0131nda g\u00f6r\u00fcnt\u00fcleme do\u011fal biyolojik s\u00fcre\u00e7lere de\u011fil, kana enjekte edilen (ve dola\u015f\u0131mla beyne ula\u015fan) yabanc\u0131 bir madde sayesinde yap\u0131l\u0131r. Hastalara beyinde metabolizmaya kat\u0131lan molek\u00fcllere eklenen radyoizotoplar enjekte edilir ve onlardan yay\u0131lan pozitronlar beyin aktivitesinin g\u00f6r\u00fcnt\u00fclenmesini sa\u011flar [22]. Hastan\u0131n PET taramas\u0131nda maruz kald\u0131\u011f\u0131 radyasyon miktar\u0131, y\u0131l boyunca \u00e7evreden ald\u0131\u011f\u0131 radyasyona g\u00f6re daha d\u00fc\u015f\u00fck seviyededir. PET radyoizotoplar\u0131n\u0131n yar\u0131-\u00f6m\u00fcrleri \u00e7ok k\u0131sa olup (2 saat civar\u0131) \u00e7abuk bozunduklar\u0131ndan, v\u00fccutta kalma s\u00fcreleri de d\u00fc\u015f\u00fckt\u00fcr[27]. G\u00fcn\u00fcm\u00fczde beyin aktivitesini g\u00f6r\u00fcnt\u00fclemede fMRI, PET\u2019ten daha \u00e7ok tercih edilir \u00e7\u00fcnk\u00fc radyasyon i\u00e7ermez, zamansal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc PET\u2019e g\u00f6re daha y\u00fcksektir ve \u00e7o\u011fu t\u0131bbi ortamda daha kolayca bulunabilir[22].<\/p>\n\n\n\n

Manyetoensefalografi (MEG) ve Elektroensefalografi (EEG)<\/strong><\/p>\n\n\n\n

MEG ve EEG\u2019nin y\u00fcksek zamansal \u00e7\u00f6z\u00fcn\u00fcrl\u00fckleri, onlar\u0131 beyin aktivitesini milisaniyeler d\u00fczeyinde \u00f6l\u00e7meye elveri\u015fli k\u0131lar. \u0130ki metodun da \u00e7al\u0131\u015fmas\u0131 i\u00e7in hastan\u0131n radyasyona maruz b\u0131rak\u0131lmas\u0131 gerekmez. Beyindeki aktiviteyi \u00f6l\u00e7mek i\u00e7in EEG elektrotlar\u0131 n\u00f6ronlarda \u00fcretilen elektrik sinyallerini tespit ederken, MEG bu elektrik sinyallerinin manyetik alanda yaratt\u0131\u011f\u0131 dalgalanmalar\u0131 \u00f6l\u00e7er. MEG\u2019nin yayg\u0131n olarak kullan\u0131lmas\u0131n\u0131n \u00f6n\u00fcndeki bir engel ise pahal\u0131 olu\u015fudur, sistemlerin fiyat\u0131 milyonlarca dolar\u0131 bulabilmektedir. EEG, \u00e7ok daha d\u00fc\u015f\u00fck maliyetinden \u00f6t\u00fcr\u00fc bahsedilen zamansal \u00e7\u00f6z\u00fcn\u00fcrl\u00fcklere ula\u015fmak i\u00e7in \u00e7ok daha yayg\u0131n olarak kullan\u0131lan bir y\u00f6ntem. Bu iki tekni\u011fin fMRI\u2019a g\u00f6re dezavantaj\u0131 ise daha d\u00fc\u015f\u00fck uzamsal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011fe sahip olmalar\u0131d\u0131r[22].<\/p>\n\n\n\n

Ele\u015ftiri ve Uyar\u0131lar<\/h1>\n\n\n\n

Baz\u0131 bilim insanlar\u0131, bilimsel dergilerde ve pop\u00fcler bas\u0131nda \u201cbeyinde yeteneklerden, belirli belleklerden ve sevgi gibi duygular\u0131n \u00fcretilmesinden sorumlu b\u00f6lgelerin ke\u015ffi\u201d gibi beyin g\u00f6r\u00fcnt\u00fcleme temelli iddialar\u0131 ele\u015ftirdi. \u00c7o\u011fu g\u00f6r\u00fcnt\u00fcleme tekni\u011fi g\u00f6rece d\u00fc\u015f\u00fck \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011fe sahip; tek bir \u00fc\u00e7 boyutlu pikselin (voksel) i\u00e7erisine y\u00fcz binlerce n\u00f6ron s\u0131\u011fd\u0131r\u0131labiliyor. Ayr\u0131ca canl\u0131larda bir\u00e7ok i\u015flev i\u00e7in beynin birden fazla b\u00f6lgesi kullan\u0131l\u0131yor; bu da bahsedilen t\u00fcrden bir iddiay\u0131 hem kullan\u0131lan ekipman\u0131n yetersizli\u011finden \u00f6t\u00fcr\u00fc onaylanamaz k\u0131l\u0131yor hem de bu tarz iddialar genelde beyin i\u015flevlerinin anatomik olarak nas\u0131l b\u00f6l\u00fcnd\u00fc\u011f\u00fc hakk\u0131nda yanl\u0131\u015f varsay\u0131mlara dayan\u0131yor. \u00c7o\u011fu beyin i\u015flevinin yaln\u0131zca \u00e7ok fazla say\u0131da k\u00fc\u00e7\u00fck beyin devresi incelenebildi\u011finde do\u011fru olarak a\u00e7\u0131klanabilece\u011fi tahmin ediliyor. Beyin g\u00f6r\u00fcnt\u00fclemeye dair \u00e7al\u0131\u015fmalar\u0131n \u00e7o\u011fu ayn\u0131 zamanda \u00f6rnek hacminin d\u00fc\u015f\u00fckl\u00fc\u011f\u00fc ve ekipman\u0131n yeterince iyi kalibre edilememesi gibi, bu \u00e7al\u0131\u015fmalar\u0131n tekrarlanabilirli\u011fini ortadan kald\u0131ran teknik problemlere de sahip \u2014 b\u00fcy\u00fck yank\u0131 uyand\u0131racak bir makale veya haber \u00fcretebilmek ad\u0131na bu tarz sorunlar ne yaz\u0131k ki ihmal edilebiliyor. Baz\u0131 durumlarda beyin g\u00f6r\u00fcnt\u00fcleme teknikleri ticari ama\u00e7larla veya yalan dedekt\u00f6r\u00fc olarak kullan\u0131labiliyor fakat bu y\u00f6ntemler bilimsel olarak onaylanm\u0131\u015f de\u011fil[28].<\/p>\n\n\n\n

Kaynak\u00e7a<\/h1>\n\n\n\n
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  28. ^<\/strong><\/a>\u00a0Satel S, Lilienfeld SO (2015). (2013).\u00a0Brainwashed: The Seductive Appeal of Mindless Neuroscience<\/em><\/a>\u00a0(\u0130ngilizce). Basic Books.\u00a0ISBN<\/a>\u00a0978\u20130465062911<\/a>.<\/li>\n<\/ol>\n","protected":false},"featured_media":1664,"template":"","meta":{"_acf_changed":false},"event_publishing_tags":[83,93,378,518,82,691,64,377,92,198,812,813,468,134,364,815,363,200,66,65,199,814,471],"kategori":[302],"class_list":["post-1672","blog_content","type-blog_content","status-publish","has-post-thumbnail","hentry","event_publishing_tags-beyin","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-eeg","event_publishing_tags-fmri","event_publishing_tags-meg","event_publishing_tags-method","event_publishing_tags-methodology","event_publishing_tags-metod","event_publishing_tags-metodoloj","event_publishing_tags-metot","event_publishing_tags-neuroimaging","event_publishing_tags-neuroscience","event_publishing_tags-norobilim","event_publishing_tags-norogoruntuleme","event_publishing_tags-pet","event_publishing_tags-sinirbilim","kategori-vikimaraton"],"acf":[],"_links":{"self":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/blog_content\/1672","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\/1672\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media\/1664"}],"wp:attachment":[{"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/media?parent=1672"}],"wp:term":[{"taxonomy":"event_publishing_tags","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/event_publishing_tags?post=1672"},{"taxonomy":"kategori","embeddable":true,"href":"https:\/\/cog-ist.com\/en\/wp-json\/wp\/v2\/kategori?post=1672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}