{"id":14357,"date":"2016-11-01T12:32:36","date_gmt":"2016-11-01T09:32:36","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=14357"},"modified":"2017-12-14T12:40:13","modified_gmt":"2017-12-14T09:40:13","slug":"beyin-goruntuleme-calismalari-bana-agriyi-goster","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/11\/01\/beyin-goruntuleme-calismalari-bana-agriyi-goster","title":{"rendered":"Beyin g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmalar\u0131:\u00a0Bana a\u011fr\u0131y\u0131 g\u00f6ster!"},"content":{"rendered":"

Fonksiyonel manyetik rezonans g\u00f6r\u00fcnt\u00fcleme (fMRI) olarak bilinen, yayg\u0131n kullan\u0131lan bir beyin g\u00f6r\u00fcnt\u00fcleme tekni\u011fiyle, a\u011fr\u0131n\u0131n beyinde yaratt\u0131\u011f\u0131 aktivite ara\u015ft\u0131r\u0131l\u0131yor. Kimi g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmalar\u0131 a\u011fr\u0131 miktar\u0131n\u0131 nesnel olarak \u00f6l\u00e7mek i\u00e7in bir yol sunabilecek modeller bulurken, baz\u0131lar\u0131 da akut a\u011fr\u0131 ile kronik a\u011fr\u0131 aras\u0131ndaki farklar\u0131 ara\u015ft\u0131r\u0131yor.<\/em><\/p>\n

David beyin taray\u0131c\u0131s\u0131nda yat\u0131yor ve elinin arkas\u0131ndan gelen \u015fiddetli lazer \u0131\u015f\u0131n\u0131na hi\u00e7bir tepki g\u00f6stermedi\u011fi g\u00f6r\u00fcl\u00fcyor. \u0130\u015flemin devam etmesinden birka\u00e7 dakika sonra, lazerin belki de durdurulmas\u0131 gerekti\u011fini s\u00f6yl\u00fcyor ve neden diye soruldu\u011funda, i\u015flemin yak\u0131c\u0131 bir aletle elinin yak\u0131lmas\u0131na al\u0131\u015f\u0131km\u0131\u015f gibi hissettirmeye ba\u015flad\u0131\u011f\u0131 yan\u0131t\u0131n\u0131 veriyor.<\/p>\n

Nadir rastlanan bir genetik mutasyondan dolay\u0131, David a\u011fr\u0131 hissetmiyor. Reading \u00dcniversitesi\u2019nde sinirbilimci olan ve David\u2019in de kat\u0131l\u0131mc\u0131s\u0131 oldu\u011fu \u00e7al\u0131\u015fmay\u0131 s\u00fcrd\u00fcren ekipten bulunan Tim Salomons, \u00e7o\u011fumuzun bu gibi bir durumun daha \u00f6nce tecr\u00fcbe ettiklerimizden hangisine benzedi\u011fini d\u00fc\u015f\u00fcnmeye gerek duymad\u0131\u011f\u0131n\u0131 s\u00f6yl\u00fcyor. Beyin aktivitesini \u00f6l\u00e7mek i\u00e7in fonksiyonel manyetik rezonans g\u00f6r\u00fcnt\u00fcleme (fMRI) olarak bilinen, yayg\u0131n kullan\u0131lan bir beyin g\u00f6r\u00fcnt\u00fcleme tekni\u011fi kullanarak, ekip David\u2019in beyninde sa\u011fl\u0131kl\u0131 bir bireydekiyle ayn\u0131 yerleri aktive eden bir a\u011fr\u0131l\u0131 uyaran tespit etti.(1)<\/sup><\/p>\n

Bu durum beyin aktivitesi ve a\u011fr\u0131 aras\u0131ndaki ili\u015fkiye \u015f\u00fcphe d\u00fc\u015f\u00fcr\u00fcyormu\u015f gibi g\u00f6z\u00fckse de, genelde g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmalar\u0131 beynin a\u011fr\u0131y\u0131 nas\u0131l i\u015fledi\u011fi konusunda \u00e7ok \u015fey g\u00f6sterdi. Kimi g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmalar\u0131 a\u011fr\u0131 miktar\u0131n\u0131 nesnel olarak \u00f6l\u00e7mek i\u00e7in bir yol sunabilecek modeller bulurken, baz\u0131lar\u0131 da akut a\u011fr\u0131 ile kronik a\u011fr\u0131 aras\u0131ndaki farklar\u0131 ara\u015ft\u0131r\u0131yor.<\/p>\n

A\u011fr\u0131n\u0131n \u00f6r\u00fcnt\u00fcs\u00fc<\/strong><\/p>\n

Di\u011fer \u00e7o\u011fu duyunun aksine, a\u011fr\u0131ya ayr\u0131lm\u0131\u015f beyin b\u00f6lgesinin kesin kan\u0131t\u0131 yoktur. Bunun yerine a\u011fr\u0131, genellikle bir\u00e7ok b\u00f6lgedeki aktiviteyle ili\u015fkilendirilir. Bu dokunma ve s\u0131cakl\u0131k gibi duyularla olu\u015fan a\u011fr\u0131n\u0131n duyusal y\u00f6nlerini i\u015fleyen somatosensoriyel korteksi ve a\u011fr\u0131n\u0131n duygusal ve g\u00fcd\u00fcsel boyutlar\u0131 i\u00e7in \u00f6nemli oldu\u011fu d\u00fc\u015f\u00fcn\u00fclen anteriorsingulat korteks ve insulay\u0131 kapsar. Di\u011fer alanlar ise prefrontal korteks ve talamustur.<\/p>\n

A\u011fr\u0131 matrisi b\u00f6lgeleri sadece a\u011fr\u0131ya \u00f6zel de\u011fildir. Bu b\u00f6lgeler fla\u015f \u0131\u015f\u0131klar ve y\u00fcksek sesler gibi dikkat \u00e7eken uyar\u0131c\u0131lar taraf\u0131ndan da etkinle\u015ftirilir. Bu uyar\u0131c\u0131 s\u00fcre\u00e7ler, \u00f6nemli olaylar\u0131 belirleme, dikkat y\u00f6neltme ve bir cevap i\u00e7in haz\u0131r hale gelmeyi i\u00e7erir. \u00c7\u00fcnk\u00fc a\u011fr\u0131 da dikkat sa\u011flar. Londra Kolej \u00dcniversitesi\u2019nde sinirbilimci olan ve fMRI \u00e7al\u0131\u015fmalar\u0131nda Salomon ile \u00e7al\u0131\u015fm\u0131\u015f olan Giandomenico Lannetti, a\u011fr\u0131 matris aktivitesinin a\u011fr\u0131n\u0131n kendisinden \u00e7ok, a\u011fr\u0131 veren olaylar\u0131n \u00f6nemiyle ili\u015fkili olabilece\u011fini iddia ediyor.<\/p>\n

Di\u011ferleri bu genel aktivitenin i\u00e7inde sakl\u0131 daha \u00f6zellikli bir \u015fey oldu\u011funu d\u00fc\u015f\u00fcn\u00fcyor. Colorado Boulder \u00dcniversitesi\u2019nde sinirbilimci olan Tor Wager, farkl\u0131 beyin b\u00f6lgelerindeki aktivite \u00f6r\u00fcnt\u00fcs\u00fcn\u00fc s\u0131n\u0131fland\u0131rabilmek ve a\u011fr\u0131n\u0131n sinirsel imzas\u0131n\u0131 geli\u015ftirmek i\u00e7in makine \u00f6\u011frenmesi y\u00f6ntemleri kulland\u0131 ( Bkz. \u015eekil 1).(2) <\/sup>Wager a\u011fr\u0131y\u0131 kodlayan bu b\u00f6lgelerin i\u00e7inde \u00e7ok \u00f6zel \u00f6r\u00fcnt\u00fcler g\u00f6sterdiklerini s\u00f6yl\u00fcyor. Di\u011fer \u00f6r\u00fcnt\u00fclerin farkl\u0131 \u015feyleri kodlad\u0131\u011f\u0131n\u0131, ancak bunlar\u0131 ay\u0131rt edebildiklerini ekliyor. \u00d6rne\u011fin di\u011fer fonksiyonlar aras\u0131nda, a\u011fr\u0131 matris b\u00f6lgeleri sosyal ret, empati, hat\u0131ra gibi duygusal deneyimlerle de aktive olmas\u0131 var; bu durum, baz\u0131lar\u0131n\u0131n bu duygular\u0131n da a\u011fr\u0131 yaratt\u0131\u011f\u0131n\u0131 s\u00f6ylemesine yol a\u00e7\u0131yor. Fakat reddedilme ve fiziksel a\u011fr\u0131 ayn\u0131 duygusal tats\u0131zl\u0131k zeminini payla\u015f\u0131yor olsalar da, g\u00f6n\u00fcl yaras\u0131 a\u00e7\u0131k\u00e7a g\u00f6\u011f\u00fcsten yaralanma durumundan farkl\u0131d\u0131r ve \u015fimdi bu fark, beyin g\u00f6r\u00fcnt\u00fclerinin detaylar\u0131nda fark edilebiliyor. Wager\u2019in ekibi bu sistemi, a\u011fr\u0131l\u0131 \u0131s\u0131y\u0131, a\u011fr\u0131l\u0131 olmayan \u0131s\u0131dan, ger\u00e7ek a\u011fr\u0131y\u0131, a\u011fr\u0131 beklentisinden ya da tekrar hat\u0131rlanmas\u0131ndan ve fiziksel a\u011fr\u0131y\u0131 duygusal olandan ay\u0131rmak i\u00e7in kulland\u0131. Ekibin algoritmas\u0131 y\u00fczde 90 oran\u0131nda a\u011fr\u0131l\u0131 olmayan deneyimleri belirlemede ve y\u00fczde 90\u2019\u0131n \u00fczerinde bir do\u011frulukla da ger\u00e7ek a\u011fr\u0131y\u0131 belirlemede ba\u015far\u0131l\u0131 oldu. Wager\u2019in sistemi ayn\u0131 zamanda alg\u0131lanan a\u011fr\u0131 seviyelerini tahmin etti ve etkili opioid bir ila\u00e7la bu beyin aktivasyonunun \u00f6nemli \u00f6l\u00e7\u00fcde d\u00fc\u015f\u00fcr\u00fcld\u00fc\u011f\u00fcn\u00fc g\u00f6sterdi. Wager ger\u00e7ekten hissedilen a\u011fr\u0131y\u0131 izleyen \u00f6l\u00e7\u00fcler geli\u015ftirmeye \u00e7al\u0131\u015ft\u0131klar\u0131n\u0131 s\u00f6yl\u00fcyor.<\/p>\n

\"\"<\/p>\n

Mutsuz zihin ve a\u011fr\u0131<\/strong><\/p>\n

A\u011fr\u0131 ayn\u0131 zamanda beklenti, dikkat, duygu ve hatta ki\u015filik gibi fakt\u00f6rlerden de etkilenir. G\u00f6r\u00fcnt\u00fcleme, ara\u015ft\u0131rmac\u0131lar\u0131n bu unsurlar\u0131n insan v\u00fccudunda neye sebep oldu\u011funu ara\u015ft\u0131rmalar\u0131n\u0131 sa\u011fl\u0131yor. \u0130rade ve hayal g\u00fcc\u00fc \u00fczerindeki kontrol kabiliyeti (\u00f6zdenetim\/\u00f6z d\u00fczenleme) a\u011fr\u0131 alg\u0131s\u0131n\u0131 de\u011fi\u015ftirebilir. Fakat Wager\u2019in ekibi bu gibi bir \u00f6zdenetimin sinirsel imza \u00fczerinde bir etkisi olmad\u0131\u011f\u0131n\u0131 buldu.(3) <\/sup>Aksine bu, beynin \u00f6d\u00fcl a\u011f\u0131nda bir devre olu\u015fturmak i\u00e7in medial prefrontal korteks ba\u011flant\u0131lar\u0131 arac\u0131l\u0131\u011f\u0131yla \u00e7al\u0131\u015fan nucleus accumbens (beyindeki \u00f6d\u00fcllendirme merkezi) gibi, beynin di\u011fer b\u00f6lgelerini aktive ediyor. Dolay\u0131s\u0131yla a\u011fr\u0131n\u0131n alg\u0131lanmas\u0131 bir sistemin sonucu gibi g\u00f6z\u00fckm\u00fcyor. Wagner geli\u015ftirdikleri a\u011fr\u0131 imzas\u0131n\u0131n, a\u011fr\u0131n\u0131n \u00f6nemli bir bile\u015feni oldu\u011funu, ama bunun tam bir a\u00e7\u0131klama vermedi\u011fini s\u00f6yl\u00fcyor.<\/p>\n

\"\"G\u00f6r\u00fcnt\u00fcleme a\u011fr\u0131n\u0131n di\u011fer bile\u015fenlerini belirlemede de yard\u0131mc\u0131. Ara\u015ft\u0131rmac\u0131lar hayvanlar \u00fczerinde yap\u0131lan \u00e7al\u0131\u015fmalardan, dikkat ve duygular\u0131n a\u011fr\u0131y\u0131, omurilikle ba\u011flanan beyin sap\u0131ndaki \u00e7e\u015fitli b\u00f6lgelerle limbik sistem (duyu merkezi) ve beyin korteksinin par\u00e7alar\u0131n\u0131 ba\u011flayan, a\u015fa\u011f\u0131ya do\u011fru seyir g\u00f6steren bir sisteme y\u00f6nlendirebildi\u011fini biliyor. Bu, a\u011fr\u0131 sinyallerini engellemek ya da artt\u0131rmak i\u00e7in beyindeki b\u00f6lgelere olanak tan\u0131r. Sinirbilimci Irene Tracey, g\u00f6r\u00fcnt\u00fclemenin, biz \u00fczg\u00fcn, gergin veya endi\u015feli oldu\u011fumuzda, bunun sadece a\u011fr\u0131n\u0131n ifade edildi\u011fi yolu de\u011fi\u015ftirmedi\u011fini, ayn\u0131 zamanda fizyolojik s\u00fcre\u00e7leri de de\u011fi\u015ftirdi\u011fini kan\u0131tlad\u0131\u011f\u0131n\u0131 belirtiyor. Tracey\u2019nin Oxford \u00dcniversitesi\u2019ndeki \u00e7al\u0131\u015fma ekibi, insanlardaki a\u011fr\u0131 mod\u00fclasyonunu ara\u015ft\u0131rmak i\u00e7in beyin g\u00f6r\u00fcnt\u00fcleme teknolojilerini kullan\u0131yor. Bir \u00e7al\u0131\u015fmalar\u0131nda,(4) <\/sup>ki\u015finin kafas\u0131 kar\u0131\u015f\u0131kken beyin sap\u0131ndaki b\u00f6lgelerin a\u011fr\u0131 sinyallerini azaltt\u0131\u011f\u0131n\u0131 belirlediler. \u015eimdiyse risk fakt\u00f6rlerini ve ki\u015fiyi kronik a\u011fr\u0131 geli\u015ftirmeye daha a\u00e7\u0131k hale getiren beyin a\u011flar\u0131n\u0131 tan\u0131mlaya \u00e7al\u0131\u015f\u0131yorlar. Tracey g\u00f6r\u00fcnt\u00fclemeyi, ki\u015finin a\u011fr\u0131 deneyiminin neden \u00f6zel bir yol izledi\u011fini ve hangi mekanizmalar\u0131n ki\u015fiyi bu duruma kilitledi\u011fini a\u00e7\u0131klamak i\u00e7in kulland\u0131klar\u0131n\u0131 s\u00f6yl\u00fcyor. Bunun, a\u011fr\u0131 terapisi i\u00e7in heyecan verici alternatifler sa\u011flayabilece\u011fini d\u00fc\u015f\u00fcn\u00fcyor. \u00a0Akut a\u011fr\u0131dan kronik a\u011fr\u0131ya olas\u0131 d\u00f6n\u00fc\u015f\u00fcm\u00fcn engellenebilmesi umut ediliyor.<\/p>\n

Akut a\u011fr\u0131 kronik a\u011fr\u0131ya d\u00f6n\u00fc\u015fmeden<\/strong><\/p>\n

Kronik a\u011fr\u0131 be\u015f ki\u015fiden birini etkileyen k\u00fcresel bir sorun. Northwestern \u00dcniversitesi\u2019nde fizyolog olan Vania Apkarian bu hastalar i\u00e7in bilimsel olarak ge\u00e7erlilik kazanm\u0131\u015f bir tedavinin olmad\u0131\u011f\u0131n\u0131 belirtiyor. Apkarian\u2019\u0131n ekibi, kronik a\u011fr\u0131 hastalar\u0131n\u0131n beyinlerinde ortak olan bir\u00e7ok fonksiyonel ve anatomik \u00f6zellik buldu, ki bu da akut a\u011fr\u0131 ile kronik a\u011fr\u0131n\u0131n temelde farkl\u0131 oldu\u011funu g\u00f6sterir. Bu farkl\u0131l\u0131klar\u0131n kronik a\u011fr\u0131n\u0131n sebebi mi yoksa sonucu mu oldu\u011funu bulmak ise bir di\u011fer \u00f6nemli nokta.<\/p>\n

Bu soruyu ele almak i\u00e7in, Apkarian\u2019\u0131n \u00e7al\u0131\u015fma ekibi ilk kronik a\u011fr\u0131 beyin g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmas\u0131n\u0131 y\u00fcr\u00fctt\u00fc.(5) <\/sup>Ara\u015ft\u0131rmac\u0131lar s\u0131rt a\u011fr\u0131s\u0131 olan 39 ki\u015fiyi bir y\u0131l boyunca periyodik olarak beyin taramas\u0131 yaparak takip etti. Bu s\u00fcre zarf\u0131nda, kronik a\u011fr\u0131 geli\u015ftirenlerin insula ve nucleus accumbens k\u0131sm\u0131nda gri madde yo\u011funlu\u011funda d\u00fc\u015f\u00fc\u015f g\u00f6zlendi. Takip eden \u00e7al\u0131\u015fmada, Apkarian\u2019\u0131n ekibi s\u0131rt a\u011fr\u0131s\u0131yla ili\u015fkilendirilen beyin aktivitesini izledi ve a\u011fr\u0131 kronikle\u015ftik\u00e7e, aktif alan\u0131n duygu ve \u00f6d\u00fclle ili\u015fkilendirilen alana kayd\u0131\u011f\u0131n\u0131 buldu.(6) <\/sup>Bu kayman\u0131n boyutu ayn\u0131 zamanda medial prefrontal korteks ve nucleus accumbens aras\u0131ndaki ba\u011flant\u0131n\u0131n g\u00fcc\u00fc ile alakal\u0131d\u0131r.<\/p>\n

Bu bulgular, sonu\u00e7lar\u0131 olan anatomik de\u011fi\u015fimlerle birlikte, akuttan kronik a\u011fr\u0131ya ge\u00e7i\u015fi tetikledi\u011fi g\u00f6r\u00fclen devreyi i\u015faret ediyor. Apkarian bunun, kronik a\u011fr\u0131n\u0131n yumurta ve tavu\u011funu belirginle\u015ftirdi\u011fini s\u00f6yl\u00fcyor. Ekibinin ayn\u0131 zamanda, kronik a\u011fr\u0131n\u0131n ana belirleyicisinin sakatlanma olmad\u0131\u011f\u0131n\u0131, ki\u015filerin beyin \u00f6zellikleri oldu\u011funu g\u00f6sterdi\u011fini de belirtiyor. Ara\u015ft\u0131rmac\u0131lar kemirgenlerde, nucleus accumbenste n\u00f6ronlar\u0131 engelleyen ila\u00e7lar kullanarak, akut a\u011fr\u0131dan kronik a\u011fr\u0131ya ge\u00e7i\u015fi engelleyebildi.(7) <\/sup>Bunun insanda da i\u015fe yaray\u0131p yaramad\u0131\u011f\u0131n\u0131 g\u00f6rmek i\u00e7in denemeler de yolda. Apkarian, kronik a\u011fr\u0131n\u0131n farkl\u0131 tipleri i\u00e7in bir dizi \u00f6zel yeni tedavi se\u00e7enekleri geli\u015ftireceklerine g\u00fcvendi\u011fini belirtiyor.<\/p>\n

Apkarian\u2019\u0131n tan\u0131mlad\u0131\u011f\u0131 beyin b\u00f6lgeleri, Wager\u2019in ekibinin \u00f6zdenetim\/\u00f6zd\u00fczenleme ile alakal\u0131 oldu\u011funu buldu\u011fu b\u00f6lgelerle ayn\u0131. Bu nedenle, \u00f6d\u00fcl-\u00f6\u011frenme ve duygusal devre \u015femas\u0131n\u0131n, akut a\u011fr\u0131n\u0131n sinirsel imzas\u0131n\u0131n par\u00e7as\u0131 olmasa da, kronik a\u011fr\u0131da kilit rol oynad\u0131\u011f\u0131 g\u00f6r\u00fcl\u00fcyor. Wager farkl\u0131 tipteki a\u011fr\u0131lar\u0131n beyinde nas\u0131l farkl\u0131 temelleri oldu\u011funu \u00f6\u011frendi\u011fimizi ve ki\u015filerin a\u011fr\u0131s\u0131n\u0131 olu\u015fturan\u0131n klasik a\u011fr\u0131 s\u00fcre\u00e7leri olmayabilece\u011fini s\u00f6yl\u00fcyor.<\/p>\n

\"\"
Ara\u015ft\u0131rmac\u0131 Tim Salomon, fonksiyonel manyetik rezonans g\u00f6r\u00fcnt\u00fclemeyle, lazer uyar\u0131c\u0131ya maruz
kalan bir ki\u015finin beyin taramalar\u0131n\u0131 inceliyor.<\/figcaption><\/figure>\n

A\u011fr\u0131metre<\/strong><\/p>\n

Bu geli\u015fmeler bizi a\u011fr\u0131y\u0131 nesnel olarak \u00f6l\u00e7ebilmeye yakla\u015ft\u0131r\u0131yor mu? Bu geli\u015fmeler hem ila\u00e7 geli\u015ftirmek i\u00e7in; hem de bebekler, komadakiler ya da ya\u015fl\u0131lar gibi a\u011fr\u0131 \u00e7ekip \u00e7ekmedi\u011fini ifade edemeyen insanlar i\u00e7in yararl\u0131 olabilir. ABD\u2019de ki\u015finin a\u011fr\u0131 imzas\u0131n\u0131 \u00e7\u0131kard\u0131\u011f\u0131n\u0131 s\u00f6yleyen ve bu hizmeti veren bir\u00e7ok \u015firket zaten var. Ve Amerikan hukuk mahkemelerinde beyin taramas\u0131n\u0131n kronik a\u011fr\u0131n\u0131n kan\u0131t\u0131 olarak kabul edildi\u011fi en az bir dava var. Ama ara\u015ft\u0131rmac\u0131lar endi\u015felerini ifade ediyor. \u00d6zellikle Wager\u2019in bulgular\u0131, kronik a\u011fr\u0131 i\u00e7in ge\u00e7erli de\u011fil. Toronto \u00dcniversitesi\u2019nde sinirbilimci olan Karen Davis, Tor ve di\u011ferlerinin kulland\u0131\u011f\u0131 teknolojinin bir uyar\u0131c\u0131ya beynin nas\u0131l kar\u015f\u0131l\u0131k verdi\u011fini kaydetti\u011fini; ancak kronik a\u011fr\u0131da uyar\u0131c\u0131 olmad\u0131\u011f\u0131n\u0131, bu y\u00fczden de farkl\u0131 bir yakla\u015f\u0131ma gerek oldu\u011funu belirtiyor.<\/p>\n

Ge\u00e7ti\u011fimiz Aral\u0131k ay\u0131nda, Washington\u2019daki Uluslararas\u0131 A\u011fr\u0131 \u00c7al\u0131\u015fmalar\u0131 Birli\u011fi (IASP), Davis\u2019in ba\u015fkanl\u0131\u011f\u0131nda a\u011fr\u0131y\u0131 tan\u0131mlamada beyin g\u00f6r\u00fcnt\u00fclemenin kullan\u0131lmas\u0131 \u00fczerinde \u00e7al\u0131\u015fmak i\u00e7in \u00f6zel bir grup olu\u015fturdu. Gelecek y\u0131l i\u00e7inde bu grup, teknolojinin ne yap\u0131p yapamayaca\u011f\u0131n\u0131, yasal d\u00fczenlemeler i\u00e7in yeterince g\u00fcvenilir olup olmad\u0131\u011f\u0131n\u0131 ve etik ve sosyal konular hakk\u0131ndaki ana hatlar\u0131 \u00e7\u0131kartacak. Davis\u2019in ve di\u011fer bir\u00e7ok ara\u015ft\u0131rmac\u0131n\u0131n endi\u015fesi fMRI\u2019n\u0131n yanl\u0131\u015f sonu\u00e7lar verebilece\u011fi. Mesela, baz\u0131 ila\u00e7lar beyin aktivitesinde de\u011fi\u015fim yapmadan vask\u00fcler (damarsal) fonksiyonlarda ve dolay\u0131s\u0131yla fMRI sinyallerinde de\u011fi\u015fime sebep olabiliyor. Davis vask\u00fcler tabanl\u0131 bir teknolojinin d\u00fc\u015f\u00fcn\u00fclmeyen bir konu oldu\u011funu s\u00f6yl\u00fcyor. Bu teknolojinin kullan\u0131lmas\u0131, beyin g\u00f6r\u00fcnt\u00fcleme a\u011fr\u0131n\u0131n de\u011ferlendirilmesinde rol \u00fcstlenecekse \u00f6nemli olacak.<\/p>\n

A\u011fr\u0131 matrisi aktif olmas\u0131na ra\u011fmen, David gibi a\u011fr\u0131 hissetmeyen birini beyin taray\u0131c\u0131s\u0131na koydu\u011funuzda, yanl\u0131\u015f bir pozitif sonu\u00e7 elde etmi\u015f olursunuz. Buna kar\u015f\u0131t olarak, aktivitenin olmamas\u0131 da a\u011fr\u0131n\u0131n olmad\u0131\u011f\u0131 y\u00f6n\u00fcnde sonu\u00e7 \u00e7\u0131kartabilir. Ancak \u00e7o\u011fu ara\u015ft\u0131rmac\u0131 bu tip bir sonucun garanti edilemeyece\u011fi noktas\u0131nda hemfikir. Wager belirli t\u00fcrdeki a\u011fr\u0131lar\u0131 do\u011frulayabileceklerini, ama herhangi bir a\u011fr\u0131n\u0131n insanlar\u0131n beyinlerinin benzersiz olmas\u0131ndan dolay\u0131 yok say\u0131lamayaca\u011f\u0131n\u0131 s\u00f6yl\u00fcyor.<\/p>\n

Kaynaklar<\/strong><\/p>\n

1)\u00a0 Salomons, T. et al. (2016), \u00a0JAMA Neurol.<\/em>, http:\/\/dx.doi.org\/10.1001\/jamaneurol.2016.0653.<\/p>\n

2) Wager, T. D. et al. (2013), N. Engl. J. Med<\/em>. 368, 1388-1397.<\/p>\n

3) Woo, C. W., Roy, M., Buhle, J. T. & Wager, T. D. (2015), PLoS<\/em><\/p>\n

Biol.<\/em> 13, e1002036.<\/p>\n

4) Tracey, I. et al. (2002), J. Neurosci.<\/em> 22, 2748-2752.<\/p>\n

5) Baliki, M. N. et al. (2012), Nature Neurosci.<\/em> 15, 1117-1119.<\/p>\n

6) Hashmi, J. A. et al. (2013), Brain<\/em> 136, 2751-2768.<\/p>\n

7) Ren, W. et al. (2016), Nature Neurosci.<\/em> 19, 220-222.<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Fonksiyonel manyetik rezonans g\u00f6r\u00fcnt\u00fcleme (fMRI) olarak bilinen, yayg\u0131n kullan\u0131lan bir beyin g\u00f6r\u00fcnt\u00fcleme tekni\u011fiyle, a\u011fr\u0131n\u0131n beyinde yaratt\u0131\u011f\u0131 aktivite ara\u015ft\u0131r\u0131l\u0131yor. Kimi g\u00f6r\u00fcnt\u00fcleme \u00e7al\u0131\u015fmalar\u0131 a\u011fr\u0131 miktar\u0131n\u0131 nesnel olarak \u00f6l\u00e7mek i\u00e7in bir yol sunabilecek modeller bulurken, baz\u0131lar\u0131 da akut a\u011fr\u0131 ile kronik a\u011fr\u0131 aras\u0131ndaki farklar\u0131 ara\u015ft\u0131r\u0131yor. David beyin taray\u0131c\u0131s\u0131nda yat\u0131yor ve elinin arkas\u0131ndan gelen \u015fiddetli lazer \u0131\u015f\u0131n\u0131na hi\u00e7bir tepki […]<\/p>\n","protected":false},"author":749,"featured_media":14360,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[190,21,1464,35],"tags":[1624,1626,254,1625,347,1521],"class_list":["post-14357","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-153-sayi","category-biyoloji","category-dosya","category-noroloji","tag-agri","tag-akut-agri","tag-beyin","tag-kronik-agri","tag-noroloji","tag-tedavi"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t