Cited by 675Neural dynamics and brain functionFunctional Brain Connectivity StudiesVisual perception and processing mechanisms

Very Slow Activity Fluctuations in Monkey Visual Cortex: Implications for Functional Brain Imaging

Leopold, D. A.·2003·Cerebral Cortex

Abstract

We examined fluctuations in band-limited power (BLP) of local field potential (LFP) signals recorded from multiple electrodes in visual cortex of the monkey during different behavioral states. We asked whether such signals demonstrated coherent fluctuations over time-scales of seconds and minutes, and would thus serve as good candidates for direct comparison with data obtained from functional magnetic resonance imaging (fMRI). We obtained the following results. (i) The BLP of the local field displayed fluctuations at many time-scales, with particularly large amplitude at very low frequencies (<0.1 Hz). (ii) These fluctuations exhibited high coherence between electrode pairs, particularly for BLP signals derived from the gamma frequency range. (iii) Coherence in the BLP, unlike that in the raw LFP, did not fall off sharply as a function of cortical distance. (iv) The structure and coherence of BLP changes were highly similar under distinctly different behavioral states. These results demonstrate the existence of widespread coherent activity fluctuations in the brain of the awake monkey over very long time-scales. We propose that such signals may make a significant contribution to the high variability observed in the time course of physiological signals, including those measured with functional imaging techniques. The results are discussed in the context of combined fMRI/electrophysiological recordings.

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Crossref · 10.1093/cercor/13.4.422

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71 of 71 references verified0 citation errors · 0 not checkable

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  • Oscillation power or amplitude fluctuations occur in a time range similar to the fMRI signal, though the oscillation itself is too fast for fMRI to follow.

    “Although the oscillation itself is too fast for fMRI to follow, its power or amplitude fluctuation falls in a similar time range as the fMRI signal (162).”
  • Spontaneous BOLD fluctuations measured in the resting state reflect underlying changes in neuronal activity.

    “Although the exact nature of the spontaneous BOLD fluctuations measured in the present analysis is unknown, the specific topography of these fluctuations and previous observations by using local field-potential recordings (36) suggest that they reflect underlying changes in neuronal activity.”

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Authors
Leopold, D. A.
Affiliations
Max Planck Society (DE)
Corresponding author
Leopold, D. A.
Venue
Cerebral Cortex
Published
2003-04-01
Volume
13
Issue
4
Pages
422-433
ISSN
  • 1047-3211 (ISSN-L)
  • 1460-2199
OpenAlex
W2167546316
Cited by
675
References
71
Citations by year
2026: 4 · 2025: 13 · 2024: 27 · 2023: 20 · 2022: 24 · 2021: 21 · 2020: 31 · 2019: 31 · 2018: 22 · 2017: 26 · 2016: 31 · 2015: 35 · 2014: 30 · 2013: 49 · 2012: 47
FWCI
9.98
Type
journal article
Language
en
Open access
closed
Locations
  • Cerebral Cortex (publishedVersion)
  • PubMed (publishedVersion)
  • MPG.PuRe (Max Planck Society) (submittedVersion)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Neural dynamics and brain function
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Functional Brain Connectivity Studies
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Visual perception and processing mechanisms
Keywords
local field potentials, visual cortex, monkeys, coherence, gamma oscillations, long time scales, behavioral state
MeSH terms
Animals, Brain Mapping, Macaca mulatta, Magnetic Resonance Imaging, Synaptic Transmission, Visual Cortex

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