| Alpha oscillations correlate with the successful inhibition of unattended stimuli. | |
| | |
MedLine Citation:
|
PMID: 20681750 Owner: NLM Status: In-Data-Review |
Abstract/OtherAbstract:
|
Because the human visual system is continually being bombarded with inputs, it is necessary to have effective mechanisms for filtering out irrelevant information. This is partly achieved by the allocation of attention, allowing the visual system to process relevant input while blocking out irrelevant input. What is the physiological substrate of attentional allocation? It has been proposed that alpha activity reflects functional inhibition. Here we asked if inhibition by alpha oscillations has behavioral consequences for suppressing the perception of unattended input. To this end, we investigated the influence of alpha activity on motion processing in two attentional conditions using magneto-encephalography. The visual stimuli used consisted of two random-dot kinematograms presented simultaneously to the left and right visual hemifields. Subjects were cued to covertly attend the left or right kinematogram. After 1.5 sec, a second cue tested whether subjects could report the direction of coherent motion in the attended (80%) or unattended hemifield (20%). Occipital alpha power was higher contralateral to the unattended side than to the attended side, thus suggesting inhibition of the unattended hemifield. Our key finding is that this alpha lateralization in the 20% invalidly cued trials did correlate with the perception of motion direction: Subjects with pronounced alpha lateralization were worse at detecting motion direction in the unattended hemifield. In contrast, lateralization did not correlate with visual discrimination in the attended visual hemifield. Our findings emphasize the suppressive nature of alpha oscillations and suggest that processing of inputs outside the field of attention is weakened by means of increased alpha activity. |
| | |
Authors:
|
Barbara F Händel; Thomas Haarmeier; Ole Jensen |
Publication Detail:
|
Type: Journal Article Date: 2010-08-03 |
Journal Detail:
|
Title: Journal of cognitive neuroscience Volume: 23 ISSN: 1530-8898 ISO Abbreviation: J Cogn Neurosci Publication Date: 2011 Sep |
Date Detail:
|
Created Date: 2011-07-07 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8910747 Medline TA: J Cogn Neurosci Country: United States |
Other Details:
|
Languages: eng Pagination: 2494-502 Citation Subset: IM |
Affiliation:
|
Radboud University Nijmegen, The Netherlands. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Perception of speech in noise: neural correlates.
Next Document: Prefrontal Cortex Tunes Category Selectivity in Visual Association Cortex.