Our psychological well-being depends on the ability to downregulate emotions (Morawetz et al., 2020). A disturbance in emotion regulation has been linked to reduced ability to activate the conscious control networks in the brain. Investigation of emotion regulation with negative images is the standard approach in the field. Smells have unique affective qualities, are neuronally distinctly processed, and are potentially more difficult to regulate cognitively. The aim of this project is to test whether emotion regulation of how we respond to negative smells in brain and behaviour relies on a network more associated to implicit emotion regulation.
We tested 30 normosmic participants using 3T imaging at Donders Institute, with the Lundstrom olfactometer for odor delivery (Lundström et al., 2010). Our paradigm involved presentation of 3 different negative odours (Pyridine, nButanol and isovaleric acid) for 8 seconds and subsequent instruction to either perceive and maintain the emotion elicited by the odour or downregulate the emotion elicited by the odour. Regulation instructions based on reappraisal techniques are given to the participants. After each trial participants rate their valence and arousal in response to the smell-condition combination. Differences in behaviour and brain activity during the trial between decrease and maintain as well as valence arousal interactions are calculated.
The main effect of regulation for valence was not significant (F1,29=3.453, p=0.073; η p 2=.106), but for arousal it was significant (F1,29; p=0.005; η p 2=.244). Initial brain analyses indicated that the tasks activates subcortical areas, insula and brain areas found in classical emotion regulation tasks. Further analysis will be conducted to elucidate the unique neuronal pattern.
In summary, conscious control of smell induced emotional states seems to be possible and similarly strong compared to classical visually induced emotional states.