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Does a contralateral decrease in alpha power during the orienting phase predict visual awareness?

Bartenbach, Hendrik (2017) Does a contralateral decrease in alpha power during the orienting phase predict visual awareness?

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Abstract:The purpose of this study was to examine the relation between visuospatial attention and visual awareness. Dehaene, Changeux, Naccache, Sackur and Sergent (2006) claimed that there is a preconscious state of processing in which a given not too salient stimulus can only be noticed when attention is deliberately directed to it. This entails that attention has to be first directed before conscious perception can occur. In this study, it was tested whether the conscious perception of a stimulus that is near the threshold of being either detected or undetected can be predicted by the direction of attention. A variation of the Posner task (1980) was used to relate the distribution of neural oscillations in the α-band as measured by electroencephalography (EEG) that are thought to be related to visuospatial attention to the reported visual awareness of the target stimulus. The results showed high correlations of reported awareness of the target stimulus and correct responses. A predictive effect of lateralized α-activity between 40 ms and 0 ms before target presentation as measured in occipital regions of the human brain on the reported awareness of the target stimulus was found. The fact that highly salient stimuli were not detected when there was no lateralization of α-activity supports Dehaene, Changeux, Naccache, Sackur and Sergent’s (2006) statement that attention is necessary for consciousness to arise.
Item Type:Essay (Master)
Faculty:BMS: Behavioural, Management and Social Sciences
Subject:77 psychology
Programme:Psychology MSc (66604)
Link to this item:http://purl.utwente.nl/essays/73735
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