Exogenous capture of visual spatial attention by olfactory-trigeminal stimuli

PLoS One. 2021 Jun 10;16(6):e0252943. doi: 10.1371/journal.pone.0252943. eCollection 2021.

Abstract

The extent to which a nasal whiff of scent can exogenously orient visual spatial attention remains poorly understood in humans. In a series of seven studies, we investigated the existence of an exogenous capture of visual spatial attention by purely trigeminal (i.e., CO2) and both olfactory and trigeminal stimuli (i.e., eucalyptol). We chose these stimuli because they activate the trigeminal system which can be considered as an alert system and are thus supposedly relevant for the individual, and thus prone to capture attention. We used them as lateralized cues in a variant of a visual spatial cueing paradigm. In valid trials, trigeminal cues and visual targets were presented on the same side whereas in invalid trials they were presented on opposite sides. To characterize the dynamics of the cross-modal attentional capture, we manipulated the interval between the onset of the trigeminal cues and the visual targets (from 580 to 1870 ms). Reaction times in trigeminal valid trials were shorter than all other trials, but only when this interval was around 680 or 1170 ms for CO2 and around 610 ms for eucalyptol. This result reflects that both pure trigeminal and olfactory-trigeminal stimuli can exogenously capture humans' spatial visual attention. We discuss the importance of considering the dynamics of this cross-modal attentional capture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Attention / physiology*
  • Carbon Dioxide / analysis
  • Cues
  • Eucalyptol / analysis
  • Humans
  • Odorants / analysis*
  • Olfactory Bulb / physiology*
  • Olfactory Perception
  • Photic Stimulation
  • Reaction Time / physiology
  • Spatial Navigation / physiology*
  • Trigeminal Nuclei / physiology*
  • Young Adult

Substances

  • Carbon Dioxide
  • Eucalyptol

Grants and funding

This research was supported by the National Center of Competence in Research (NCCR) for the Affective Sciences, financed by a grant from the Swiss National Science Foundation hosted by the University of Geneva, and was also supported by a research grant from Firmenich, SA, to David Sander and Patrik Vuilleumier. The funder provided support in the form of salaries for author MI and provided material to conduct the experiments but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.