کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5705885 1603166 2017 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Development of contrast normalization mechanisms during childhood and adolescence
ترجمه فارسی عنوان
توسعه سازوکارهای نوسازی کنتراست در دوران کودکی و نوجوانی
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی سیستم های حسی
چکیده انگلیسی
Contrast sensitivity is regulated by neural mechanisms that flexibly adjust responsiveness to optimize stimulus encoding across different environments. Here we studied the developmental status of gain control mechanisms in school-age children (5-17 years) and adults using a visual masking paradigm. A variable contrast, spatially random 2-D noise test pattern was masked by the presence of a superimposed independent noise pattern presented at 0, 12 and 40% contrast. Frequency-tagged steady state visual evoked potentials were used to separately record responses to the test (5.14 Hz) and the mask (7.2 Hz). By incrementally increasing the test contrast we measured contrast response functions for each mask contrast. The unmasked contrast response functions were largely similar in shape across age, but peak amplitude was higher in the children. Masking shifted the contrast response function rightward on the contrast axis in both the adults and older children, elevating contrast thresholds by a similar factor across age. However, in younger children, masking resulted in a change in the slope of the contrast response function. These findings suggest that immaturity in the contrast normalization process persists until approximately 11 years of age.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Vision Research - Volume 133, April 2017, Pages 12-20
نویسندگان
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