Augmenting EEG-global-coherence with auditory and visual noise: Multisensory internal stochastic resonance

Area of Science:

• Neuroscience
• Sensory Processing
• Computational Neuroscience

Background:

• Multisensory integration is crucial for perception.
• Stochastic resonance (SR) describes how noise can enhance signal detection.
• Internal SR in the brain, particularly in electroencephalographic (EEG) coherence, remains underexplored.

Purpose of the Study:

• To investigate the phenomenon of multisensory internal stochastic resonance (MISR) in human EEG coherence.
• To determine if intermediate levels of auditory or visual noise enhance EEG coherence in response to another sensory modality.
• To explore the role of noise in visuoauditory processing within the central nervous system.

Main Methods:

• EEG data was recorded from human subjects.
• Global Weighted Coherence (GWC) was used to quantify EEG coherence.
• Auditory and visual noise stimuli were systematically varied (zero, optimal, high levels).
• GWC was compared across different noise conditions and basal activity.

Main Results:

• An intermediate level of input noise was found to enhance GWC in the majority of subjects.
• This enhancement occurred when noise was applied to one sensory modality while the other was also noisy.
• The findings demonstrate the occurrence of MISR in visuoauditory processing.

Conclusions:

• Multisensory internal stochastic resonance (MISR) is an electrophysiological phenomenon observable in human EEG coherence.
• Optimal noise levels can facilitate neural processing in multisensory environments.
• This research provides novel insights into the role of noise in the human brain's sensory integration mechanisms.