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A brain-computer-interface for the detection and modulation of gamma band activity.

Salari N, Rose M - Brain Sci (2013)

Bottom Line: The BCI incorporates modules for online detection of various artifacts (including microsaccades) and the artifacts were continuously fed back to the volunteer.The analyses revealed a high level of accuracy with respect to frequency and topography for the gamma-band modulations.Thus, the developed BCI can be used to manipulate the fast oscillatory activity with a high level of specificity.

View Article: PubMed Central - PubMed

Affiliation: NeuroImage Nord, Department of Systems Neuroscience, University Medical Center Hamburg Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. n.salari@uke.de.

ABSTRACT
Gamma band oscillations in the human brain (around 40 Hz) play a functional role in information processing, and a real-time assessment of gamma band activity could be used to evaluate the functional relevance more directly. Therefore, we developed a source based Brain-Computer-Interface (BCI) with an online detection of gamma band activity in a selective brain region in the visual cortex. The BCI incorporates modules for online detection of various artifacts (including microsaccades) and the artifacts were continuously fed back to the volunteer. We examined the efficiency of the source-based BCI for Neurofeedback training of gamma- and alpha-band (8-12 Hz) oscillations and compared the specificity for the spatial and frequency domain. Our results demonstrated that volunteers learned to selectively switch between modulating alpha- or gamma-band oscillations and benefited from online artifact information. The analyses revealed a high level of accuracy with respect to frequency and topography for the gamma-band modulations. Thus, the developed BCI can be used to manipulate the fast oscillatory activity with a high level of specificity. These selective modulations can be used to assess the relevance of fast neural oscillations for information processing in a more direct way, i.e., by the adaptive presentation of stimuli within well-described brain states.

No MeSH data available.


Related in: MedlinePlus

The neurofeedback design. Neurofeedback training: during the passive period (20 s) volunteers fixated the central cross. This period was used to assess an actual baseline value of alpha or gamma current density power in the ROIs. In the feedback period (second 21–30) participants tried to increase the current density power in the ROIs (value at fixation) and at the same time avoid EOG (bar above value) and EMG (electromyography) (bar below value) artifacts by keeping the bars green. As an artifact occurred (at least one of the bars red) the presented value was set to zero. The success of the intentionally increased artifact free gamma or alpha values was presented after the feedback period (success display).
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brainsci-03-01569-f002: The neurofeedback design. Neurofeedback training: during the passive period (20 s) volunteers fixated the central cross. This period was used to assess an actual baseline value of alpha or gamma current density power in the ROIs. In the feedback period (second 21–30) participants tried to increase the current density power in the ROIs (value at fixation) and at the same time avoid EOG (bar above value) and EMG (electromyography) (bar below value) artifacts by keeping the bars green. As an artifact occurred (at least one of the bars red) the presented value was set to zero. The success of the intentionally increased artifact free gamma or alpha values was presented after the feedback period (success display).

Mentions: (4) The change of gamma- or alpha-band activity in the LOC was visualized by a value at fixation. In addition, two bars were added above and below the feedback value, representing EOG and EMG artifacts (see Section 2.3 Procedure and Figure 2).


A brain-computer-interface for the detection and modulation of gamma band activity.

Salari N, Rose M - Brain Sci (2013)

The neurofeedback design. Neurofeedback training: during the passive period (20 s) volunteers fixated the central cross. This period was used to assess an actual baseline value of alpha or gamma current density power in the ROIs. In the feedback period (second 21–30) participants tried to increase the current density power in the ROIs (value at fixation) and at the same time avoid EOG (bar above value) and EMG (electromyography) (bar below value) artifacts by keeping the bars green. As an artifact occurred (at least one of the bars red) the presented value was set to zero. The success of the intentionally increased artifact free gamma or alpha values was presented after the feedback period (success display).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061891&req=5

brainsci-03-01569-f002: The neurofeedback design. Neurofeedback training: during the passive period (20 s) volunteers fixated the central cross. This period was used to assess an actual baseline value of alpha or gamma current density power in the ROIs. In the feedback period (second 21–30) participants tried to increase the current density power in the ROIs (value at fixation) and at the same time avoid EOG (bar above value) and EMG (electromyography) (bar below value) artifacts by keeping the bars green. As an artifact occurred (at least one of the bars red) the presented value was set to zero. The success of the intentionally increased artifact free gamma or alpha values was presented after the feedback period (success display).
Mentions: (4) The change of gamma- or alpha-band activity in the LOC was visualized by a value at fixation. In addition, two bars were added above and below the feedback value, representing EOG and EMG artifacts (see Section 2.3 Procedure and Figure 2).

Bottom Line: The BCI incorporates modules for online detection of various artifacts (including microsaccades) and the artifacts were continuously fed back to the volunteer.The analyses revealed a high level of accuracy with respect to frequency and topography for the gamma-band modulations.Thus, the developed BCI can be used to manipulate the fast oscillatory activity with a high level of specificity.

View Article: PubMed Central - PubMed

Affiliation: NeuroImage Nord, Department of Systems Neuroscience, University Medical Center Hamburg Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. n.salari@uke.de.

ABSTRACT
Gamma band oscillations in the human brain (around 40 Hz) play a functional role in information processing, and a real-time assessment of gamma band activity could be used to evaluate the functional relevance more directly. Therefore, we developed a source based Brain-Computer-Interface (BCI) with an online detection of gamma band activity in a selective brain region in the visual cortex. The BCI incorporates modules for online detection of various artifacts (including microsaccades) and the artifacts were continuously fed back to the volunteer. We examined the efficiency of the source-based BCI for Neurofeedback training of gamma- and alpha-band (8-12 Hz) oscillations and compared the specificity for the spatial and frequency domain. Our results demonstrated that volunteers learned to selectively switch between modulating alpha- or gamma-band oscillations and benefited from online artifact information. The analyses revealed a high level of accuracy with respect to frequency and topography for the gamma-band modulations. Thus, the developed BCI can be used to manipulate the fast oscillatory activity with a high level of specificity. These selective modulations can be used to assess the relevance of fast neural oscillations for information processing in a more direct way, i.e., by the adaptive presentation of stimuli within well-described brain states.

No MeSH data available.


Related in: MedlinePlus