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Induction of an Isoelectric Brain State to Investigate the Impact of Endogenous Synaptic Activity on Neuronal Excitability In Vivo
Published on: March 31, 2016
EEG phase patterns reflect the selectivity of neural firing
Benedict Shien Wei Ng1, Nikos K Logothetis, Christoph Kayser
1Max Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.
Cerebral Cortex (New York, N.Y. : 1991)
|February 21, 2012
Summary
Neural firing patterns shape the phase, not amplitude, of brain oscillations, carrying sensory information. This reveals how brain activity encodes stimuli beyond simple power changes.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Auditory Neuroscience
Background:
- Brain oscillations are crucial for sensory processing and cognitive functions.
- While oscillation amplitude is well-studied, oscillation phase patterns may hold more information.
- The neural basis of phase-based information encoding remains unclear.
Purpose of the Study:
- To investigate whether neural firing patterns imprint onto the phase or amplitude of brain oscillations.
- To compare the stimulus selectivity of neural firing rates and electroencephalogram (EEG) oscillations.
- To elucidate the neural correlates of oscillatory phase patterns in auditory processing.
Main Methods:
- Recorded scalp EEGs in humans and intracortical local field potentials (LFPs) and single neurons in macaque auditory cortex.
- Utilized naturalistic sound stimuli across both human and macaque experiments.
- Employed stimulus decoding techniques to analyze neural firing rates and oscillation phase/amplitude.
Main Results:
- Stimulus-selective neural firing patterns were found to imprint on the phase, not amplitude, of slow (theta band) oscillations in LFPs and EEG.
- Stimuli discriminable by firing rates were also discriminable by phase patterns, but not by oscillation amplitude.
- Stimulus-specific phase patterns persisted even without increased oscillation power.
Conclusions:
- Findings support a neural basis for stimulus-selective and entrained EEG phase patterns.
- Reveals a deeper interrelation between encephalographic signals and neural firing beyond amplitude covariations.
- Oscillatory phase, rather than amplitude, is a key carrier of stimulus information in the auditory cortex.
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