Limits...
Steady-state BOLD response modulates low frequency neural oscillations.

Wang YF, Liu F, Long ZL, Duan XJ, Cui Q, Yan JH, Chen HF - Sci Rep (2014)

Bottom Line: Specifically, the harmonic phenomenon of SSBR was task-related and independent of the neurovascular coupling.These findings suggested that the SSBRs represent non-linear neural oscillations but not brain activations.In comparison with the conventional general linear model, the SSBRs provide us novel insights into the non-linear brain activities, low frequency neural oscillations, and neuroplasticity of brain training and cognitive activities.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.

ABSTRACT
Neural oscillations are the intrinsic characteristics of brain activities. Traditional electrophysiological techniques (e.g., the steady-state evoked potential, SSEP) have provided important insights into the mechanisms of neural oscillations in the high frequency ranges (>1 Hz). However, the neural oscillations within the low frequency ranges (<1 Hz) and deep brain areas are rarely examined. Based on the advantages of the low frequency blood oxygen level dependent (BOLD) fluctuations, we expected that the steady-state BOLD responses (SSBRs) would be elicited and modulate low frequency neural oscillations. Twenty six participants completed a simple reaction time task with the constant stimuli frequencies of 0.0625 Hz and 0.125 Hz. Power analysis and hemodynamic response function deconvolution method were used to extract SSBRs and recover neural level signals. The SSEP-like waveforms were observed at the whole brain level and at several task-related brain regions. Specifically, the harmonic phenomenon of SSBR was task-related and independent of the neurovascular coupling. These findings suggested that the SSBRs represent non-linear neural oscillations but not brain activations. In comparison with the conventional general linear model, the SSBRs provide us novel insights into the non-linear brain activities, low frequency neural oscillations, and neuroplasticity of brain training and cognitive activities.

Show MeSH

Related in: MedlinePlus

The relative power of Task/Resting throughout the brain.Aside from regions above the threshold in the t-test, slight SSBRs were shown throughout the brain. Paired-sample t-test revealed that the HRF deconvolution did not significantly change the distribution of SSBRs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4260215&req=5

f3: The relative power of Task/Resting throughout the brain.Aside from regions above the threshold in the t-test, slight SSBRs were shown throughout the brain. Paired-sample t-test revealed that the HRF deconvolution did not significantly change the distribution of SSBRs.

Mentions: The SSBRs after HRF deconvolution throughout the brain are slightly higher (not statistically significant different) than those before HRF deconvolution. This suggests that the SSBR is independent of HRF convolution, a key hypothesis in the conventional general linear model (GLM). Except for the SA and SMA regions, most areas of the brain showed a little higher power (the ratio of Task/Rest >1 but not arrives significance) on task conditions than on the resting condition (Figure 3). Although there were no significant differences, to certain extent, the stimuli presented in a constant signal frequency changed the brain state or rhythmic activity. This result, therefore, supports the perspective of neuroscience that cognitive processing is implemented by widely distributed brain areas acting in collaboration20.


Steady-state BOLD response modulates low frequency neural oscillations.

Wang YF, Liu F, Long ZL, Duan XJ, Cui Q, Yan JH, Chen HF - Sci Rep (2014)

The relative power of Task/Resting throughout the brain.Aside from regions above the threshold in the t-test, slight SSBRs were shown throughout the brain. Paired-sample t-test revealed that the HRF deconvolution did not significantly change the distribution of SSBRs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260215&req=5

f3: The relative power of Task/Resting throughout the brain.Aside from regions above the threshold in the t-test, slight SSBRs were shown throughout the brain. Paired-sample t-test revealed that the HRF deconvolution did not significantly change the distribution of SSBRs.
Mentions: The SSBRs after HRF deconvolution throughout the brain are slightly higher (not statistically significant different) than those before HRF deconvolution. This suggests that the SSBR is independent of HRF convolution, a key hypothesis in the conventional general linear model (GLM). Except for the SA and SMA regions, most areas of the brain showed a little higher power (the ratio of Task/Rest >1 but not arrives significance) on task conditions than on the resting condition (Figure 3). Although there were no significant differences, to certain extent, the stimuli presented in a constant signal frequency changed the brain state or rhythmic activity. This result, therefore, supports the perspective of neuroscience that cognitive processing is implemented by widely distributed brain areas acting in collaboration20.

Bottom Line: Specifically, the harmonic phenomenon of SSBR was task-related and independent of the neurovascular coupling.These findings suggested that the SSBRs represent non-linear neural oscillations but not brain activations.In comparison with the conventional general linear model, the SSBRs provide us novel insights into the non-linear brain activities, low frequency neural oscillations, and neuroplasticity of brain training and cognitive activities.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 610054, China.

ABSTRACT
Neural oscillations are the intrinsic characteristics of brain activities. Traditional electrophysiological techniques (e.g., the steady-state evoked potential, SSEP) have provided important insights into the mechanisms of neural oscillations in the high frequency ranges (>1 Hz). However, the neural oscillations within the low frequency ranges (<1 Hz) and deep brain areas are rarely examined. Based on the advantages of the low frequency blood oxygen level dependent (BOLD) fluctuations, we expected that the steady-state BOLD responses (SSBRs) would be elicited and modulate low frequency neural oscillations. Twenty six participants completed a simple reaction time task with the constant stimuli frequencies of 0.0625 Hz and 0.125 Hz. Power analysis and hemodynamic response function deconvolution method were used to extract SSBRs and recover neural level signals. The SSEP-like waveforms were observed at the whole brain level and at several task-related brain regions. Specifically, the harmonic phenomenon of SSBR was task-related and independent of the neurovascular coupling. These findings suggested that the SSBRs represent non-linear neural oscillations but not brain activations. In comparison with the conventional general linear model, the SSBRs provide us novel insights into the non-linear brain activities, low frequency neural oscillations, and neuroplasticity of brain training and cognitive activities.

Show MeSH
Related in: MedlinePlus