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Human cortical traveling waves: dynamical properties and correlations with responses.

Patten TM, Rennie CJ, Robinson PA, Gong P - PLoS ONE (2012)

Bottom Line: The spatiotemporal behavior of human EEG oscillations is investigated.Traveling waves in the alpha and theta ranges are found to be common in both prestimulus and poststimulus EEG activity.The dynamical properties of these waves, including their speeds, directions, and durations, are systematically characterized for the first time, and the results show that there are significant changes of prestimulus spontaneous waves in the presence of an external stimulus.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, University of Sydney, Sydney, New South Wales, Australia.

ABSTRACT
The spatiotemporal behavior of human EEG oscillations is investigated. Traveling waves in the alpha and theta ranges are found to be common in both prestimulus and poststimulus EEG activity. The dynamical properties of these waves, including their speeds, directions, and durations, are systematically characterized for the first time, and the results show that there are significant changes of prestimulus spontaneous waves in the presence of an external stimulus. Furthermore, the functional relevance of these waves is examined by studying how they are correlated with reaction times on a single trial basis; prestimulus alpha waves traveling in the frontal-to-occipital direction are found to be most correlated to reaction speeds. These findings suggest that propagating waves of brain oscillations might be involved in mediating long-range interactions between widely distributed parts of human cortex.

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Wavelet power spectrum of a typical subject averaged over all trials and electrodes in normalized power units.The stimulus onset time is at 0 ms.
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pone-0038392-g003: Wavelet power spectrum of a typical subject averaged over all trials and electrodes in normalized power units.The stimulus onset time is at 0 ms.

Mentions: To detect the main oscillatory frequency bands of EEG activity, on which more fine-grained analyses were performed, we first carried out a time-frequency analysis for the EEG signals. We studied power spectrum from 0.5 to 80 Hz, and found that the signals showed very little power above 26 Hz compared to that of lower frequencies. Thus, 26 Hz was established as the upper cut off frequency for further investigation. We also closely inspected the delta range (0.5–4 Hz) oscillations and found that the Go and NoGo conditions had indistuiguishable characteristics, indicating that the delta oscillations could be neglected in the comparison between the two conditions. Therefore, 4 Hz was established as the lower cut off frequency in our study. A wavelet transform from 4–26 Hz was then performed on the entire time series of each subject. To better present the dominant frequencies of EEG activity, for each subject the wavelet power spectrum was averaged over all 100 Go trials and then averaged over all electrodes. We found that most of the subjects had strong alpha oscillations (8–12 Hz) before the stimulus onset, and strong theta oscillations (4–8 Hz) after the stimulus onset; representative results from a subject are shown in Fig. 3, from which we can see that such alpha oscillations peaking at 10.6 Hz and theta oscillations peaking at 5.8 Hz.


Human cortical traveling waves: dynamical properties and correlations with responses.

Patten TM, Rennie CJ, Robinson PA, Gong P - PLoS ONE (2012)

Wavelet power spectrum of a typical subject averaged over all trials and electrodes in normalized power units.The stimulus onset time is at 0 ms.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3366935&req=5

pone-0038392-g003: Wavelet power spectrum of a typical subject averaged over all trials and electrodes in normalized power units.The stimulus onset time is at 0 ms.
Mentions: To detect the main oscillatory frequency bands of EEG activity, on which more fine-grained analyses were performed, we first carried out a time-frequency analysis for the EEG signals. We studied power spectrum from 0.5 to 80 Hz, and found that the signals showed very little power above 26 Hz compared to that of lower frequencies. Thus, 26 Hz was established as the upper cut off frequency for further investigation. We also closely inspected the delta range (0.5–4 Hz) oscillations and found that the Go and NoGo conditions had indistuiguishable characteristics, indicating that the delta oscillations could be neglected in the comparison between the two conditions. Therefore, 4 Hz was established as the lower cut off frequency in our study. A wavelet transform from 4–26 Hz was then performed on the entire time series of each subject. To better present the dominant frequencies of EEG activity, for each subject the wavelet power spectrum was averaged over all 100 Go trials and then averaged over all electrodes. We found that most of the subjects had strong alpha oscillations (8–12 Hz) before the stimulus onset, and strong theta oscillations (4–8 Hz) after the stimulus onset; representative results from a subject are shown in Fig. 3, from which we can see that such alpha oscillations peaking at 10.6 Hz and theta oscillations peaking at 5.8 Hz.

Bottom Line: The spatiotemporal behavior of human EEG oscillations is investigated.Traveling waves in the alpha and theta ranges are found to be common in both prestimulus and poststimulus EEG activity.The dynamical properties of these waves, including their speeds, directions, and durations, are systematically characterized for the first time, and the results show that there are significant changes of prestimulus spontaneous waves in the presence of an external stimulus.

View Article: PubMed Central - PubMed

Affiliation: School of Physics, University of Sydney, Sydney, New South Wales, Australia.

ABSTRACT
The spatiotemporal behavior of human EEG oscillations is investigated. Traveling waves in the alpha and theta ranges are found to be common in both prestimulus and poststimulus EEG activity. The dynamical properties of these waves, including their speeds, directions, and durations, are systematically characterized for the first time, and the results show that there are significant changes of prestimulus spontaneous waves in the presence of an external stimulus. Furthermore, the functional relevance of these waves is examined by studying how they are correlated with reaction times on a single trial basis; prestimulus alpha waves traveling in the frontal-to-occipital direction are found to be most correlated to reaction speeds. These findings suggest that propagating waves of brain oscillations might be involved in mediating long-range interactions between widely distributed parts of human cortex.

Show MeSH