Olfaction spontaneously highlights visual saliency map

Abstract

Attention is intrinsic to our perceptual representations of sensory inputs. Best characterized in the visual domain, it is typically depicted as a spotlight moving over a saliency map that topographically encodes strengths of visual features and feedback modulations over the visual scene. By introducing smells to two well-established attentional paradigms, the dot-probe and the visual-search paradigms, we find that a smell reflexively directs attention to the congruent visual image and facilitates visual search of that image without the mediation of visual imagery. Furthermore, such effect is independent of, and can override, top-down bias. We thus propose that smell quality acts as an object feature whose presence enhances the perceptual saliency of that object, thereby guiding the spotlight of visual attention. Our discoveries provide robust empirical evidence for a multimodal saliency map that weighs not only visual but also olfactory inputs.

Odours reduce the magnitude of object substitution masking for matching visual targets in females

“…Essentially, it seems odours prime visual representations of matching objects, thus making them more salient and more difficult to mask. Previous studies have shown that olfactory-visual integration serves to enhance perception when olfactory and visual information is congruent (Chen et al, 2013;Robinson et al, 2013). The current study builds on these previous findings by showing that cross-modal associations between odours and their corresponding visual objects can enhance object identification when visual awareness is disrupted.…”

“…Surprisingly, there has been little focus on gender differences in multisensory integration between olfaction and other modalities, despite accumulating research on interactions between olfaction and vision. Several olfactory-visual experiments have been conducted with a majority of female participants (Chen et al, 2013;Seo, Roidl, Muller, & Negoias, 2010;Seo, Arshamian, et al, 2010;Zhou et al, 2012), so it is possible that previous results have been driven by larger multisensory effects in females than males.…”

“…These interactions also are bidirectional. As noted, certain visual features can enhance odour perception, but perhaps more unexpectedly, specific odours also can influence visual perception (Chen, Zhou, Chen, He, & Zhou, 2013;Robinson, Mattingley, & Reinhard, 2013;Zhou, Jiang, He, & Chen, 2010). Under conditions of binocular rivalry, for example, matching odorants can prolong durations of perceptual dominance of matching versus mismatching visual objects (Zhou et al, 2010;Zhou, Zhang, Chen, Wang, & Chen, 2012).…”

“…In this study, we asked whether familiar odorants, such as orange and mint, can alter participants' ability to detect matching visual objects, such as images orange or mint leaves, under conditions of OSM. Given previous findings that such odours can enhance the perceptual salience of matching visual objects (Chen et al, 2013;Robinson et al, 2013), we predicted that OSM would be reduced for matching odour-object pairs relative to mismatching pairs. We also examined whether olfactory-visual OSM performance differed for males and females by recruiting and testing a large cohort of female (N = 36; Experiment 1) and male (N = 36; Experiment 2) participants.…”

The Role of Olfactory Challenge Tests in Incipient Dementia and Clinical Trial Design

“…It will be interesting to see if the newer paradigms of olfactory testing offer significant benefits. From a broader perspective, the study of olfaction sits at the intersection of many vibrant disciplines, including neuroscience, genetics, and immunology [77,78]. For the AD field, animal model studies, some employing highly innovative techniques [79], are yielding important insights; neurogenesis within the olfactory structures holds treatment potential [80]; the possibility that biopsy of olfactory mucosa might aid early diagnosis is again under discussion [2•, 34].…”