The quest for single trial correlations in multimodal EEG-fMRI data

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• Technological advancements enable simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recordings.
• Investigating the coupling between EEG and fMRI signals is crucial for integrating their temporal and spatial resolutions.
• The correlation timing between EEG and fMRI features remains debated, impacting multimodal data analysis.

Purpose of the Study:

• To analyze the relationship between EEG and fMRI signals during a face processing task.
• To determine if single-trial dynamics of face processing correlate across EEG and fMRI modalities.
• To assess the extent of shared versus modality-specific information in EEG-fMRI during face perception.

Main Methods:

• Analysis of simultaneously recorded EEG and fMRI data from four subjects performing a face processing task.
• Separate estimation of single-trial (ST) dynamics for both EEG and fMRI data.
• Correlation analysis to identify shared information between the two modalities.

Main Results:

• Reliable estimation of single-trial (ST) face processing dynamics was achieved separately in EEG and fMRI data.
• No significant correlation was found between the EEG and fMRI signals across subjects.
• This indicates that information processed within each modality is largely distinct.

Conclusions:

• Despite technical advances in simultaneous EEG-fMRI, direct correlation between modalities for face processing is not evident in this study.
• Modality-specific information processing appears to be more prominent than shared information during this specific cognitive task.
• Further research is needed to understand the conditions under which EEG and fMRI signals may exhibit cross-modal correlations.