Séminaire d'équipe SCALab

Marine R. Coeugnet

Titre : Scents of Focus: How Pleasant and Unpleasant Odors Shape Cognitive Engagement

Description : The Yerkes-Dodson law (1908) posits that there is an optimal level of arousal that allows for peak performance in a task. To enhance cognitive performance and foster concentration, it may be beneficial to modulate this level of arousal using olfactory stimuli, which are powerful affective modulators. Depending on our emotional state, odors could help us either relax or energize, thus helping us reach the optimal level of arousal for the task.
Russell's Affective Circumplex Model (1980) suggests that emotions can be mapped along two primary dimensions: valence (pleasant vs. unpleasant) and arousal (level of emotional activation). While the impact of odors on modulating arousal has been well-documented (Herz & Engen, 1996), the connection between odors and valence is equally important. This raises the question: Can a negative but stimulating odor improve performance as much as a positive and stimulating odor?
In this presentation, we explore the mediating role of odor valence, while also investigating brain dynamics using EEG to better understand how these factors interact to modulate focus and engagement in a moderate cognitive effort task, such as active listening to an audiobook. While no significant changes were observed in physiological measures like heart rate and respiratory rate, the EEG results revealed more nuanced insights. Specifically, positive odors seemed to be associated with faster and stronger brain responses, particularly early in the task. Interestingly, both menthol (positive) and cadaverine (negative) increased alpha waves (mu rhythm) in centro-parietal regions, which are typically linked to internal focus and motor inhibition. Cadaverine, in particular, also triggered beta waves in frontal regions, commonly associated with attention and cognitive control. These findings imply that odors influence different brain wave frequencies, modulating focus and cognitive effort in subtle but significant ways, thus highlighting their potential to optimize cognitive performance.