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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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The reaction speed index (RSI) and wave index (WI) over trials for a typical subject; solid line for RSIand dashed line for WI. The wave index was calculated for the F-to-O alpha waves.
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pone-0038392-g009: The reaction speed index (RSI) and wave index (WI) over trials for a typical subject; solid line for RSIand dashed line for WI. The wave index was calculated for the F-to-O alpha waves.

Mentions: Figure 9 shows the typical wave index of the prestimulus alpha waves and reaction speed index of one subject, as defined above, over trials. It is well known that reaction time fluctuates significantly over trials even when external stimuli are identical. For all subjects in our recordings, one can clearly see such variations. As shown in Fig. 9, there were great trial-by-trial fluctuations in both indices. However, the two indices appear to follow a similar fluctuating trend; larger wave occurrences have larger response speeds (i.e., subjects reacted faster), and smaller wave occurrences have smaller response speeds (i.e., subjects responded slower). This, therefore, demonstrates a potential correlation between the two indices. To directly quantify this and to test whether the trial-by-trial fluctuations of the waves can predict the response speeds, we calculated the Pearson correlation coefficient of the two indices (see Methods) for the 16 subjects. The results for the alpha waves during 500 ms preceding stimulus onset, including correlation values and the corresponding p values obtained from permutation tests (see Methods), are summarized in Table 2; the results indicate that prestimulus alpha waves had significant correlations with reaction speeds (r = 0.58, p = 0.001).


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

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

The reaction speed index (RSI) and wave index (WI) over trials for a typical subject; solid line for RSIand dashed line for WI. The wave index was calculated for the F-to-O alpha waves.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0038392-g009: The reaction speed index (RSI) and wave index (WI) over trials for a typical subject; solid line for RSIand dashed line for WI. The wave index was calculated for the F-to-O alpha waves.
Mentions: Figure 9 shows the typical wave index of the prestimulus alpha waves and reaction speed index of one subject, as defined above, over trials. It is well known that reaction time fluctuates significantly over trials even when external stimuli are identical. For all subjects in our recordings, one can clearly see such variations. As shown in Fig. 9, there were great trial-by-trial fluctuations in both indices. However, the two indices appear to follow a similar fluctuating trend; larger wave occurrences have larger response speeds (i.e., subjects reacted faster), and smaller wave occurrences have smaller response speeds (i.e., subjects responded slower). This, therefore, demonstrates a potential correlation between the two indices. To directly quantify this and to test whether the trial-by-trial fluctuations of the waves can predict the response speeds, we calculated the Pearson correlation coefficient of the two indices (see Methods) for the 16 subjects. The results for the alpha waves during 500 ms preceding stimulus onset, including correlation values and the corresponding p values obtained from permutation tests (see Methods), are summarized in Table 2; the results indicate that prestimulus alpha waves had significant correlations with reaction speeds (r = 0.58, p = 0.001).

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