کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4346895 | 1296809 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Differential effects of eyes open or closed in darkness on brain activation patterns in blind subjects
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موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Differential effects of eyes open or closed in darkness on brain activation patterns in blind subjects Differential effects of eyes open or closed in darkness on brain activation patterns in blind subjects](/preview/png/4346895.png)
چکیده انگلیسی
In functional brain imaging, specific task conditions can be compared to a reference condition which is often eyes-open or eyes-closed in darkness without the execution of a specific task. Previous fMRI studies in sighted subjects have shown that eyes-open in darkness, without visual stimulation, increases the relative activity in cortical ocular motor and attentional areas (“exteroceptive” state; contrast OPENÂ >Â CLOSED). By contrast, eyes-closed causes a relative signal increase in sensory systems (“interoceptive” state; contrast CLOSEDÂ >Â OPEN). In the present study we used fMRI to determine whether these differential brain activity states can also be found in congenitally blind subjects: there were intragroup differences between the OPEN and CLOSED conditions. These differences were, however, less pronounced and occurred in other areas than in sighted controls. The contrast OPENÂ >Â CLOSED revealed a relative signal increase in the left frontal eye field, the middle occipital gyrus bilaterally and in the anterior cingulum. Relative signal increases in occipital cortex areas and the anterior cingulum were also apparent for this contrast in the intergroup comparison (congenitally totally blind subjects vs. sighted controls). They reflect the increased attentional load or arousal during the eyes-open condition and could be indicative of a functional reorganization of the occipital cortex in the blind. The contrast CLOSEDÂ >Â OPEN in the congenitally totally blind subjects lead to relative activations in the somatosensory cortex bilaterally, the middle temporal gyrus on the left and the frontal gyri on the right. These activations are residues of the “interoceptive” state found in sighted controls.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuroscience Letters - Volume 466, Issue 1, 27 November 2009, Pages 30-34
Journal: Neuroscience Letters - Volume 466, Issue 1, 27 November 2009, Pages 30-34
نویسندگان
K. Hüfner, T. Stephan, V.L. Flanagin, A. Deutschländer, A. Stein, R. Kalla, T. Dera, G. Fesl, K. Jahn, M. Strupp, T. Brandt,