The relationship between negative BOLD responses and ERS and ERD of alpha/beta oscillations in visual and motor cortex

• Published in: NeuroImage (Orlando, Fla.) Vol. 199; pp. 635 - 650
• Main Authors: Wilson, Ross, Mullinger, Karen J., Francis, Susan T., Mayhew, Stephen D.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2019; Elsevier Limited
• Subjects: Adult; Alpha; Alpha Rhythm - physiology; Beta Rhythm - physiology; Correlation analysis; Cortex (motor); Cortex (somatosensory); Cortical Synchronization - physiology; Cross-modal; Deactivation; EEG; EEG-fMRI; ERS; Female; Functional magnetic resonance imaging; Functional Neuroimaging - methods; Humans; Magnetic Resonance Imaging; Male; Medical imaging; Motor Activity - physiology; Motor Cortex - diagnostic imaging; Motor Cortex - physiology; NBR; Negative BOLD; Oscillations; Pattern Recognition, Visual - physiology; Receptive field; Sensorimotor integration; Sensory integration; Synchronization; Visual cortex; Visual Cortex - diagnostic imaging; Visual Cortex - physiology; Visual stimuli; Alpha; Negative BOLD; EEG-fMRI; Cross-modal; ERS; NBR
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2019.06.009

Previous work has investigated the electrophysiological origins of the intra-modal (within the stimulated sensory cortex) negative BOLD fMRI response (NBR, decrease from baseline) but little attention has been paid to the origin of cross-modal NBRs, those in a different sensory cortex. In the current study we use simultaneous EEG-fMRI recordings to assess the neural correlates of both intra- and cross-modal responses to left-hemifield visual stimuli and right-hand motor tasks, and evaluate the balance of activation and deactivation between the visual and motor systems. Within- and between-subject covariations of EEG and fMRI responses to both tasks are assessed to determine how patterns of event-related desynchronization/synchronisation (ERD/ERS) of alpha/beta frequency oscillations relate to the NBR in the two sensory cortices. We show that both visual and motor tasks induce intra-modal NBR and cross-modal NBR (e.g. visual stimuli evoked NBRs in both visual and motor cortices). In the EEG data, bilateral intra-modal alpha/beta ERD were consistently observed to both tasks, whilst the cross-modal EEG response varied across subjects between alpha/beta ERD and ERS. Both the mean cross-modal EEG and fMRI response amplitudes showed a small increase in magnitude with increasing task intensity. In response to the visual stimuli, subjects displaying cross-modal ERS of motor beta power displayed a significantly larger magnitude of cross-modal NBR in motor cortex. However, in contrast to the motor stimuli, larger cross-modal ERD of visual alpha power was associated with larger cross-modal visual NBR. Single-trial correlation analysis provided further evidence of relationship between EEG signals and the NBR, motor cortex beta responses to motor tasks were significantly negatively correlated with cross-modal visual cortex NBR amplitude, and positively correlated with intra-modal motor cortex PBR. This study provides a new body of evidence that the coupling between BOLD and low-frequency (alpha/beta) sensory cortex EEG responses extends to cross-modal NBR. •EEG-fMRI study of negative BOLD in stimulated and unstimulated sensory cortex.•Visual and motor stimuli both induce intra- and cross-modal negative BOLD responses.•CM ERS of alpha/beta power inconsistent across subjects, but linked to larger CM NBR.•Single-trial EEG-NBR correlations further support neural origin of NBR.