کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4329424 1614219 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Human EEG very high frequency oscillations reflect the number of matches with a template in auditory short-term memory
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب (عمومی)
پیش نمایش صفحه اول مقاله
Human EEG very high frequency oscillations reflect the number of matches with a template in auditory short-term memory
چکیده انگلیسی

Auditory perception comprises bottom-up as well as top-down processes. While research in the past has revealed many neural correlates of bottom-up processes, less is known about top-down modulation. Memory processes have recently been associated with oscillations in the gamma-band of human EEG (30 Hz and above) which are enhanced when incoming information matches a stored memory template. Therefore, we investigated event-related potentials (ERPs) and gamma-band activity in 17 healthy participants in a Go/NoGo-task. They listened to four frequency-modulated (FM) sounds which varied regarding the frequency range traversed and the direction of frequency modulation. One sound was defined as target and required a button press. The results of ERPs (N1, P2, N2, and P3) were consistent with previous studies. Analysis of evoked gamma-band responses yielded no significant task-dependent modulation, but we observed a stimulus dependency, which was also present in a control experiment: The amplitude of evoked gamma responses showed an inverted U-shape as a function of stimulus frequency. Investigation of total gamma activity revealed functionally relevant responses at high frequencies (90 Hz to 250 Hz), which showed significant modulations by matches with STM: Complete matches led to the strongest enhancements (starting around 100 ms after stimulus onset) and partial matches resulted in intermediate ones. The results support the conclusion that very high frequency oscillations (VHFOs) are markers of active stimulus discrimination in STM matching processes and are attributable to higher cognitive functions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain Research - Volume 1220, 18 July 2008, Pages 81–92
نویسندگان
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