RT Journal Article
SR Electronic
T1 Alpha/beta power decreases track the fidelity of stimulus-specific information
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 633107
DO 10.1101/633107
A1 Benjamin J. Griffiths
A1 Stephen D. Mayhew
A1 Karen J. Mullinger
A1 João Jorge
A1 Ian Charest
A1 Maria Wimber
A1 Simon Hanslmayr
YR 2019
UL http://biorxiv.org/content/early/2019/05/09/633107.abstract
AB Massed synchronised neuronal firing is detrimental to information processing. When networks of task-irrelevant neurons fire in unison, they mask the signal generated by task-critical neurons. On a macroscopic level, mass synchronisation of these neurons can contribute to the ubiquitous alpha/beta (8-30Hz) oscillations. Reductions in the amplitude of these oscillations, therefore, may reflect a boost in the processing of high-fidelity information within the cortex. Here, we test this hypothesis. Twenty-one participants completed an associative memory task while undergoing simultaneous EEG-fMRI recordings. Using representational similarity analysis, we quantified the amount of stimulus-specific information represented within the BOLD signal on every trial. When correlating this metric with concurrently-recorded alpha/beta power, we found a significant negative correlation which indicated that as alpha/beta power decreased, our metric of stimulus-specific information increased. This effect generalised across cognitive tasks, as the negative relationship could be observed during visual perception and episodic memory retrieval. Further analysis revealed that this effect could be better explained by alpha/beta power decreases providing favourable conditions for information processing, rather than directly representing stimulus-specific information. Together, these results indicate that alpha/beta power decreases parametrically track the fidelity of both externally-presented and internally-generated stimulus-specific information represented within the cortex.