Craddock, M, Poliakoff, E, El-deredy, W et al. (2 more authors) (2017) Pre-stimulus alpha oscillations over somatosensory cortex predict tactile misperceptions. Neuropsychologia, 96. pp. 9-18. ISSN 0028-3932
Abstract
Fluctuations of pre-stimulus oscillatory activity in the somatosensory alpha band (8-14Hz) observed using human EEG and MEG have been shown to influence the detection of supra- and peri-threshold somatosensory stimuli. However, some reports of touch occur even without a stimulus. We investigated the possibility that pre-stimulus alpha oscillations might also influence these false reports of touch - known as tactile misperceptions. We recorded EEG while participants performed the Somatic Signal Detection Task (SSDT), in which participants must detect brief, peri-threshold somatosensory targets. We found that pre-stimulus oscillatory power in the somatosensory alpha range exhibited a negative linear relationship with reporting of touch at electrode clusters over both contralateral and ipsilateral somatosensory regions. As pre-stimulus alpha power increased, the probability of reporting a touch declined; as it decreased, the probability of reporting a touch increased. This relationship was stronger on trials without a somatosensory stimulus than on trials with a somatosensory stimulus, although was present for both trial types. Spatio-temporal cluster-based permutation analysis also found that pre-stimulus alpha was lower on trials when touch was reported - irrespective of whether it was present - over contralateral and ipsilateral somatosensory cortices, as well as left frontocentral areas. We argue that alpha power may reflect changes in response criterion rather than sensitivity alone. Low alpha power relates to a low barrier to reporting a touch even when one is not present, while high alpha power is linked to less frequent reporting of touch overall.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2017 Elsevier Ltd. This is an author produced version of a paper published in Neuropsychologia. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | EEG; alpha oscillations; perception; pre-stimulus; signal detection; somatosensory |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Psychology (Leeds) |
Funding Information: | Funder Grant number BBSRC BB/L006618/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 06 Jan 2017 09:58 |
Last Modified: | 23 Jun 2023 22:20 |
Published Version: | https://doi.org/10.1016/j.neuropsychologia.2016.12... |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.neuropsychologia.2016.12.030 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:110152 |