Target enhancement or distractor suppression? Functionally distinct alpha oscillations form the basis of attention

Recent advances in attention research have been propelled by the debate on target enhancement versus distractor suppression. A predominant neural correlate of attention is the modulation of alpha oscillatory power (similar to 10 Hz), which signifies shifts of attention in time, space and between sensory modalities. However, the under-specified functional role of alpha oscillations limits the progress of tracking down the neurocognitive basis of attention. In this short opinion article, we review and critically examine a synthesis of three conceptual and methodological aspects that are indispensable for a mechanistic understanding of the role of alpha oscillations for attention. (a) Precise mapping of the anatomical source and the temporal response profile of neural signals reveals distinct alpha oscillatory processes that implement facilitatory versus suppressive components of attention. (b) A testable framework enables unanimous association of alpha modulation with either target enhancement or different forms of distractor suppression (active vs. automatic). (c) Linking anatomically specified alpha oscillations to behavior reveals the causal nature of alpha oscillations for attention. The three reviewed aspects substantially enrich study design, data analysis and interpretation of results to achieve the goal of understanding how anatomically specified and functionally relevant neural oscillations contribute to the implementation of facilitatory versus suppressive components of attention.

Automated summary

Recent advances in attention research have been driven by the debate on target enhancement versus distractor suppression. The modulation of alpha oscillatory power has been identified as a predominant neural correlate of attention, but its functional role remains under-specified. This article reviews three essential aspects for a mechanistic understanding of how alpha oscillations contribute to the implementation of facilitatory versus suppressive components of attention, enriching study design, data analysis, and interpretation of results.