Exogenous attention interferes with endogenous attention processing via lateralized alpha power

Abstract

Current theories of attention differentiate exogenous (bottom-up) from endogenous (top- down) orienting of visuospatial attention. While both forms of attentional processing engage different processes, endogenous and exogenous attention are thought to share processing resources, as shown by recent empirical evidence of their functional interactions. Here, we aim to uncover the neurobiological basis of how salient events that drive exogenous attention disrupts endogenous attention processes. We hypothesize that interference from exogenous attention over endogenous attention involves alpha-band activity, a neural marker of visuospatial attention. To test this hypothesis, we contrast the effects of endogenous attention across two experimental conditions: a single cueing condition where endogenous attention is engaged in isolation, and a double cueing condition where endogenous attention is concurrently engaged with exogenous attention. Our results are consistent with previous work and show that the concurrent engagement of exogenous attention interferes with endogenous attention processes. Importantly, we evaluate our main hypothesis using a moderated mediation model. We found that changes in alpha-band activity mediate the relationship between endogenous attention and its benefits on task performance, and that the interference of exogenous attention on endogenous attention occurs via the moderation of this indirect effect. Altogether, our results substantiate a model of attention, whereby top-down and bottom-up attentional processes compete for shared neurophysiological resources. This model accounts for the observed patterns of interference between exogenous and endogenous attention.

Differential and Overlapping Effects between Exogenous and Endogenous Attention Shape Perceptual Facilitation during Visual Processing

“…These results denote that beyond early differential effects, exogenous and endogenous impact sensory processing in a similar fashion. These results support growing literature suggesting that these attention processes share neural processes at the sensory level (Landry et al, 2022). Likewise, our mediation analysis also shows analogous effects for the second and third component (which corresponded to a contralateral component and a more centroparietal topographical pattern, respectively; see Appendix B).…”

“…This outcome is consistent with results from brain imaging (e.g., Dugué, Merriam, Heeger, & Carrasco, 2020). Our recent EEG work aligns with these findings and showed that exogenous and endogenous attention interfere with each other early during visual processing (Landry, da Silva Castanheira, Raz, Baillet, & Sackur, 2022).…”

“…We analyzed data from 3 tasks: the non-cueing task, the endogenous cueing task, and the exogenous cueing task. Data from all four tasks has been disseminated elsewhere (Landry et al, 2022). The experiment was a single testing session and lasted approximately 2 hours.…”