Abstract
Our perception and cognitive integration of the environment are based on multisensory processes. Thus, all sensory-perceptual systems reciprocally influence each other. This is also true for the less-studied olfactory sense, which has repeatedly been shown to modulate visual exploratory behavior. For example, when they explore a complex visual scene adult subjects orient their gaze more rapidly and for shorter duration to the stimuli that are congruent, rather than incongruent, with the odor context (Seigneuric et al., 2010). Such an odor-based visual bias can be mediated by emotional processes, as the valence of odors can modulate how efficiently facial expressions are processed (e.g., Leppänen & Hietanen, 2003). So far, only few studies have assessed whether and how odorants administered at subliminal levels affect visual processing. In this study, odorants chosen to be hedonically contrasted (i.e. strawberry and Butiric Acid) were delivered at subliminal levels to evaluate whether they modulate the ability to detect facially-expressed emotions. Participant's detection threshold for both odorants was first measured using a single ascending staircase procedure with a triple forced-choice. Then, while exposed or not to a subliminal odor, they were required to visually detect an emotional target, in determining whether an expressive face (i.e. expressing anger, disgust, fear, joy or sadness) was present in an array of 6 faces among which 5 were neutral. During the detection task, different oculometric parameters were collected (e.g., emotional target and distractors treatment time, target fixation latency, etc.). It came out that the odors influence different oculometric parameters. In sum, the present findings confirm that odors delivered below threshold can modulate visual search for emotional faces, and clarify its different effects on visual exploration for facial expressions.
Meeting abstract presented at VSS 2014