Limits...
High-frequency Broadband Modulations of Electroencephalographic Spectra.

Onton J, Makeig S - Front Hum Neurosci (2009)

Bottom Line: High-frequency cortical potentials in electroencephalographic (EEG) scalp recordings have low amplitudes and may be confounded with scalp muscle activities.Multi-dimensional scaling revealed significant but spatially complex relationships between mean broadband brain IM effects and the valence of the imagined emotions.Thus, contrary to prevalent assumption, unitary modes of spectral modulation of frequencies encompassing the beta, gamma, and high gamma frequency ranges can be isolated from scalp-recorded EEG data and may be differentially associated with brain sources and cognitive activities.

View Article: PubMed Central - PubMed

Affiliation: Institute for Neural Computation, University of California San Diego, La Jolla, CA, USA.

ABSTRACT
High-frequency cortical potentials in electroencephalographic (EEG) scalp recordings have low amplitudes and may be confounded with scalp muscle activities. EEG data from an eyes-closed emotion imagination task were linearly decomposed using independent component analysis (ICA) into maximally independent component (IC) processes. Joint decomposition of IC log spectrograms into source- and frequency-independent modulator (IM) processes revealed three distinct classes of IMs that separately modulated broadband high-frequency ( approximately 15-200 Hz) power of brain, scalp muscle, and likely ocular motor IC processes. Multi-dimensional scaling revealed significant but spatially complex relationships between mean broadband brain IM effects and the valence of the imagined emotions. Thus, contrary to prevalent assumption, unitary modes of spectral modulation of frequencies encompassing the beta, gamma, and high gamma frequency ranges can be isolated from scalp-recorded EEG data and may be differentially associated with brain sources and cognitive activities.

No MeSH data available.


Mean behavioral ratings of the 15 emotion labels used in the experiment. Subjects rated each word on two scales: ‘Valence (negative-positive)’ and ‘Arousal (calm-active)’ labeled ‘Very negative’ (0) to ‘Very positive’ (10), and ‘Low activity’ (0) to ‘Stimulating’ (10), respectively, with the midpoint (5) indicated as ‘Neutral’ on both scales. Rating data were collected from 100 subjects via an anonymous on-line survey. Each emotion point represents the mean z-score and the error bars the standard deviation. Colors are applied from a continuous color spectrum and used simply to differentiate emotions from one another and do not reflect any objective metric or emotion grouping.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2806183&req=5

Figure 7: Mean behavioral ratings of the 15 emotion labels used in the experiment. Subjects rated each word on two scales: ‘Valence (negative-positive)’ and ‘Arousal (calm-active)’ labeled ‘Very negative’ (0) to ‘Very positive’ (10), and ‘Low activity’ (0) to ‘Stimulating’ (10), respectively, with the midpoint (5) indicated as ‘Neutral’ on both scales. Rating data were collected from 100 subjects via an anonymous on-line survey. Each emotion point represents the mean z-score and the error bars the standard deviation. Colors are applied from a continuous color spectrum and used simply to differentiate emotions from one another and do not reflect any objective metric or emotion grouping.

Mentions: Figure 7 shows results of the web survey by 100 subjects of differences between the 15 emotion terms used in this experiment on two dimensions long found to characterize differences between affective connotations of emotion names and many other words, valence and arousal (Russell, 1980). As expected, these results conform to common understanding and experience of these emotion terms, with love, joy, happiness, etc. rated as ‘positive’ valence (i.e., good) emotions, frustration, anger, fear, grief, etc. as ‘negative’ valence (bad), frustration, anger, joy and excitement as associated with relatively ‘active’ arousal, and contentment, grief, and sadness with relative ‘calm.’


High-frequency Broadband Modulations of Electroencephalographic Spectra.

Onton J, Makeig S - Front Hum Neurosci (2009)

Mean behavioral ratings of the 15 emotion labels used in the experiment. Subjects rated each word on two scales: ‘Valence (negative-positive)’ and ‘Arousal (calm-active)’ labeled ‘Very negative’ (0) to ‘Very positive’ (10), and ‘Low activity’ (0) to ‘Stimulating’ (10), respectively, with the midpoint (5) indicated as ‘Neutral’ on both scales. Rating data were collected from 100 subjects via an anonymous on-line survey. Each emotion point represents the mean z-score and the error bars the standard deviation. Colors are applied from a continuous color spectrum and used simply to differentiate emotions from one another and do not reflect any objective metric or emotion grouping.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2806183&req=5

Figure 7: Mean behavioral ratings of the 15 emotion labels used in the experiment. Subjects rated each word on two scales: ‘Valence (negative-positive)’ and ‘Arousal (calm-active)’ labeled ‘Very negative’ (0) to ‘Very positive’ (10), and ‘Low activity’ (0) to ‘Stimulating’ (10), respectively, with the midpoint (5) indicated as ‘Neutral’ on both scales. Rating data were collected from 100 subjects via an anonymous on-line survey. Each emotion point represents the mean z-score and the error bars the standard deviation. Colors are applied from a continuous color spectrum and used simply to differentiate emotions from one another and do not reflect any objective metric or emotion grouping.
Mentions: Figure 7 shows results of the web survey by 100 subjects of differences between the 15 emotion terms used in this experiment on two dimensions long found to characterize differences between affective connotations of emotion names and many other words, valence and arousal (Russell, 1980). As expected, these results conform to common understanding and experience of these emotion terms, with love, joy, happiness, etc. rated as ‘positive’ valence (i.e., good) emotions, frustration, anger, fear, grief, etc. as ‘negative’ valence (bad), frustration, anger, joy and excitement as associated with relatively ‘active’ arousal, and contentment, grief, and sadness with relative ‘calm.’

Bottom Line: High-frequency cortical potentials in electroencephalographic (EEG) scalp recordings have low amplitudes and may be confounded with scalp muscle activities.Multi-dimensional scaling revealed significant but spatially complex relationships between mean broadband brain IM effects and the valence of the imagined emotions.Thus, contrary to prevalent assumption, unitary modes of spectral modulation of frequencies encompassing the beta, gamma, and high gamma frequency ranges can be isolated from scalp-recorded EEG data and may be differentially associated with brain sources and cognitive activities.

View Article: PubMed Central - PubMed

Affiliation: Institute for Neural Computation, University of California San Diego, La Jolla, CA, USA.

ABSTRACT
High-frequency cortical potentials in electroencephalographic (EEG) scalp recordings have low amplitudes and may be confounded with scalp muscle activities. EEG data from an eyes-closed emotion imagination task were linearly decomposed using independent component analysis (ICA) into maximally independent component (IC) processes. Joint decomposition of IC log spectrograms into source- and frequency-independent modulator (IM) processes revealed three distinct classes of IMs that separately modulated broadband high-frequency ( approximately 15-200 Hz) power of brain, scalp muscle, and likely ocular motor IC processes. Multi-dimensional scaling revealed significant but spatially complex relationships between mean broadband brain IM effects and the valence of the imagined emotions. Thus, contrary to prevalent assumption, unitary modes of spectral modulation of frequencies encompassing the beta, gamma, and high gamma frequency ranges can be isolated from scalp-recorded EEG data and may be differentially associated with brain sources and cognitive activities.

No MeSH data available.