کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5045393 1475559 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Pre-stimulus alpha oscillations over somatosensory cortex predict tactile misperceptions
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب رفتاری
پیش نمایش صفحه اول مقاله
Pre-stimulus alpha oscillations over somatosensory cortex predict tactile misperceptions
چکیده انگلیسی


- Pre-stimulus alpha brain activity influences detection of peri-threshold touch.
- Alpha power over somatosensory cortex was measured using EEG to hits and false alarms.
- The probability of reporting touch decreased as contralateral alpha power increased.
- Ipsilateral alpha power showed a similar relationship for false alarms.
- Accounts of the role of pre-stimulus power need to consider true and false perceptions.

Fluctuations of pre-stimulus oscillatory activity in the somatosensory alpha band (8-14 Hz) 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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Neuropsychologia - Volume 96, February 2017, Pages 9-18
نویسندگان
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