Elsevier

Neuropsychologia

Volume 56, April 2014, Pages 393-400
Neuropsychologia

Alpha power increases in right parietal cortex reflects focused internal attention

https://doi.org/10.1016/j.neuropsychologia.2014.02.010Get rights and content
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Highlights

  • This study investigated the functional significance of EEG alpha activity.

  • Right-parietal alpha power increased as a function of internal attention demands.

  • Alpha power increases during divergent thinking indicates focused attention.

  • Right-parietal alpha may reflect activity of the ventral attention network.

Abstract

This study investigated the functional significance of EEG alpha power increases, a finding that is consistently observed in various memory tasks and specifically during divergent thinking. It was previously shown that alpha power is increased when tasks are performed in mind—e.g., when bottom-up processing is prevented. This study aimed to examine the effect of task-immanent differences in bottom-up processing demands by comparing two divergent thinking tasks, one intrinsically relying on bottom-up processing (sensory-intake task) and one that is not (sensory-independence task). In both tasks, stimuli were masked in half of the trials to establish conditions of higher and lower internal processing demands. In line with the hypotheses, internal processing affected performance and led to increases in alpha power only in the sensory-intake task, whereas the sensory-independence task showed high levels of task-related alpha power in both conditions. Interestingly, conditions involving focused internal attention showed a clear lateralization with higher alpha power in parietal regions of the right hemisphere. Considering evidence from fMRI studies, right-parietal alpha power increases may correspond to a deactivation of the right temporoparietal junction, reflecting an inhibition of the ventral attention network. Inhibition of this region is thought to prevent reorienting to irrelevant stimulation during goal-driven, top-down behavior, which may serve the executive function of task shielding during demanding cognitive tasks such as idea generation and mental imagery.

Keywords

Attention
Memory
Inhibition
EEG
Alpha
Divergent thinking

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