title: Metacognitive awareness of covert somatosensory attention corresponds to contralateral alpha power.
abstract: Studies on metacognition have shown that participants can report on their performance on a wide range of perceptual, memory and behavioral tasks. We know little, however, about the ability to report on one's attentional focus. The degree and direction of somatosensory attention can, however, be readily discerned through suppression of alpha band frequencies in EEG/MEG produced by the somatosensory cortex. Such top-down attentional modulations of cortical excitability have been shown to result in better discrimination performance and decreased response times. In this study we asked whether the degree of attentional focus is also accessible for subjective report, and whether such evaluations correspond to the amount of somatosensory alpha activity. In response to auditory cues participants maintained somatosensory attention to either their left or right hand for intervals varying randomly between 5 and 32 seconds, while their brain activity was recorded with MEG. Trials were terminated by a probe sound, to which they reported their level of attention on the cued hand right before probe-onset. Using a beamformer approach, we quantified the alpha activity in left and right somatosensory regions, one second before the probe. Alpha activity from contra- and ipsilateral somatosensory cortices for high versus low attention trials were compared. As predicted, the contralateral somatosensory alpha depression correlated with higher reported attentional focus. Finally, alpha activity two to three seconds before the probe-onset was correlated with attentional focus. We conclude that somatosensory attention is indeed accessible to metacognitive awareness.
authors.affiliation: Donders Centre for Cognitive Neuroimaging, Box 9104, 6500 HE Nijmegen, The Netherlands; Institute for Computing and Information Sciences, Radboud University Nijmegen, Box 9010, 6500 GL Nijmegen, The Netherlands. Electronic address: stephen.whitmarsh@gmail.com.
authors.forename: Stephen
authors.initials: S
authors.lastname: Whitmarsh
authors.forename: Henk
authors.initials: H
authors.lastname: Barendregt
authors.forename: Jan-Mathijs
authors.initials: JM
authors.lastname: Schoffelen
authors.forename: Ole
authors.initials: O
authors.lastname: Jensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000513:Alpha Rhythm / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013003:Somatosensory Cortex / Q000502:physiology*; D055815:Young Adult
keywords: Alpha; Attention; Awareness; Metacognition; Neural oscillations