IMR Press / JIN / Volume 20 / Issue 1 / DOI: 10.31083/j.jin.2021.01.422
Open Access Original Research
Alpha and theta mechanisms operating in internal-external attention competition
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1 Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna-Campus of Cesena, 47521 Cesena, Italy
*Correspondence: (Elisa Magosso)
J. Integr. Neurosci. 2021, 20(1), 1–19;
Submitted: 21 December 2020 | Revised: 21 January 2021 | Accepted: 3 March 2021 | Published: 30 March 2021
Copyright: © 2021 The Authors. Published by IMR Press.
This is an open access article under the CC BY 4.0 license (

Attention is the ability to prioritize a set of information at expense of others and can be internally- or externally-oriented. Alpha and theta oscillations have been extensively implicated in attention. However, it is unclear how these oscillations operate when sensory distractors are presented continuously during task-relevant internal processes, in close-to-real-life conditions. Here, EEG signals from healthy participants were obtained at rest and in three attentional conditions, characterized by the execution of a mental math task (internal attention), presentation of pictures on a monitor (external attention), and task execution under the distracting action of picture presentation (internal-external competition). Alpha and theta power were investigated at scalp level and at some cortical regions of interest (ROIs); moreover, functional directed connectivity was estimated via spectral Granger Causality. Results show that frontal midline theta was distinctive of mental task execution and was more prominent during competition compared to internal attention alone, possibly reflecting higher executive control; anterior cingulate cortex appeared as mainly involved and causally connected to distant (temporal/occipital) regions. Alpha power in visual ROIs strongly decreased in external attention alone, while it assumed values close to rest during competition, reflecting reduced visual engagement against distractors; connectivity results suggested that bidirectional alpha influences between frontal and visual regions could contribute to reduce visual interference in internal attention. This study can help to understand how our brain copes with internal-external attention competition, a condition intrinsic in the human sensory-cognitive interplay, and to elucidate the relationships between brain oscillations and attentional functions/dysfunctions in daily tasks.

Alpha and theta power
Mental math task
Visual distractors
Top-down and bottom-up influences
Granger Causality
Fig. 1.
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