據(jù)11月12日的《科學(xué)》雜志報(bào)道說(shuō),,當(dāng)我們對(duì)正在看的東西是知曉的話,,我們的大腦神經(jīng)元會(huì)比我們?cè)诜怯幸庾R(shí)性地記錄我們所看到的東西時(shí)以一種更為可靠的模式來(lái)發(fā)放沖動(dòng),。 據(jù)Aaron Schurger及其同僚披露,,這些發(fā)現(xiàn)可幫助研究人員評(píng)估當(dāng)患者處于麻醉或昏迷時(shí)的意識(shí)狀態(tài),。它們還可能用于研究像精神分裂癥,、自閉癥及分離性障礙等疾病時(shí)的腦功能。
研究人員應(yīng)用功能性核磁共振成像(或fMRI)來(lái)記錄志愿者進(jìn)行一項(xiàng)簡(jiǎn)單的視覺(jué)范疇的辨別作業(yè)時(shí)的腦部的活動(dòng)模式,。 具體地說(shuō),,這些志愿者看著有2種顏色的圖畫(huà),他們必須確認(rèn)他們所看到的是臉部或是房屋的圖畫(huà),。 這些圖畫(huà)中有些受到了色彩掩蔽技術(shù)的處理,因此在視覺(jué)系統(tǒng)中的探查亮度變化的部分可探查到圖畫(huà)中的物體,,但記錄色彩的部分則不會(huì)探查到圖畫(huà)中的物體,。 因此,在這些案例中,,這些志愿者仍然“在看”圖畫(huà),,盡管他們并不知曉正在這樣做。
文章的作者發(fā)現(xiàn),,與非意識(shí)性知曉有關(guān)的神經(jīng)活動(dòng)比那些有意識(shí)知曉的神經(jīng)活動(dòng)的可重復(fù)性要差,。 過(guò)去,科學(xué)家們發(fā)現(xiàn),,這一腦激活的強(qiáng)度和時(shí)間長(zhǎng)短取決于一個(gè)人是在有意識(shí)的情況下或是在無(wú)意識(shí)的情況下來(lái)處理有關(guān)的資訊,。Schurger及其同僚的發(fā)現(xiàn)如今添加了可重復(fù)性作為需要考慮的第三個(gè)因素。(生物谷Bioon.com)
生物谷推薦原始出處:
Science November 12, 2009 DOI: 10.1126/science.1180029
Reproducibility Distinguishes Conscious From Nonconscious Neural Representations
Aaron Schurger,1,2,* Francisco Pereira,1,2 Anne Treisman,1 Jonathan D. Cohen1,2
What qualifies a neural representation for a role in subjective experience? Previous evidence suggests that the duration and intensity of the neural response to a sensory stimulus are factors. We introduce another attribute—the reproducibility of a pattern of neural activity across different episodes—that predicts specific and measurable differences between conscious and nonconscious neural representations indepedently of duration and intensity. We found that conscious neural activation patterns are relatively reproducible when compared to nonconscious neural activation patterns corresponding to the same perceptual content. This is not adequately explained by a difference in signal-to-noise ratio.
1 Department of Psychology, Princeton University, Princeton, New Jersey, USA
2 Center for the Study of Brain, Mind, and Behavior, Princeton University, Princeton, New Jersey, USA