Decoding laughter: MEG insights on auditory perception of volitional and spontaneous vocalizations

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Abstract Submission 

Clara El Khantour¹, Anne-Lise Saive², Yann Harel¹, Hamza Abdelhedi¹, Jens Kreitewolf³, Arthur Dehgan¹, Sinead Hsi-Yi Chen⁴, Sophie Scott⁵, Guillaume Dumas⁶, Karim Jerbi⁷

¹University of Montreal, Montreal, Quebec, ²Institut de recherche Paul Bocuse, Écully, Auvergne-Rhône-Alpes, ³McGill University, Montreal, Quebec, ⁴University College London, London, United Kingdom, ⁵University College London, London, London, ⁶CHUSJ Research Center, University of Montreal, Montreal, Quebec, ⁷Computational and Cognitive Neuroscience Lab, Department of Psychology, University of Montreal, Montreal, Quebec

Clara El Khantour  
University of Montreal
Montreal, Quebec

Anne-Lise Saive  
Institut de recherche Paul Bocuse
Écully, Auvergne-Rhône-Alpes

Yann Harel  
University of Montreal
Montreal, Quebec

Hamza Abdelhedi  
University of Montreal
Montreal, Quebec

Jens Kreitewolf  
McGill University
Montreal, Quebec

Arthur Dehgan  
University of Montreal
Montreal, Quebec

Sinead Hsi-Yi Chen  
University College London
London, United Kingdom

Sophie Scott  
University College London
London, London

Guillaume Dumas  
CHUSJ Research Center, University of Montreal
Montreal, Quebec

Karim Jerbi  
Computational and Cognitive Neuroscience Lab, Department of Psychology, University of Montreal
Montreal, Quebec

Laughter is a non-verbal emotional vocalization we use in our everyday life. Its complexe nuances allows it to serve various purposes including spontaneous emotional expression (spontaneous laughter) and communication during social interaction (voluntary laughter) (Scott et al., 2014). Using fMRI, distinct brain regions have been found to be involved during the perception of distinct types of laughter (McGettigan et al., 2015): Regions typically involved in auditory processing are more activated when hearing spontaneous laughter while greater activations were found in regions implicated in mentalizing in the case of volitional laughter. EEG investigations have reported differences in the N100 and P200 ERP components between volitional and spontaneous laughter (Kosilo et al., 2021). Another study has identified differences also in later stages (Late Positive Component; Conde et al., 2022). Although encouraging, there are still many open questions when it comes to the neural processing patterns of this vocalization. This current project investigates the neural correlates of the perception and discrimination of laughter in healthy individuals through the application of magnetoencephalography (MEG).

The brain activity of 32 healthy subjects was recorded in MEG (CTF-MEG, 270 channels) during two tasks, a passive listening condition and an active task consisting of classifying the type of laughter heard. The MEG data were preprocessed using the MNE-BIDS-PIPELINE (Gramfort et al., 2014) on 27 subjects (5 subjects rejected due to technical problems during recording). In total, 3 stimulus categories were employed: laughter stimuli, comprising 25 volitional and 25 spontaneous instances, and two sets of control stimuli. The duration of the stimuli was between 1.5 and 3 sec. Evoked related potentials (ERPs) were obtained by averaging epochs (-0.5s to 1.5s) for each task and conditions respectively. We applied a non-parametric cluster-level paired t-test for spatio-temporal data to compare the ERPs between our conditions.

At the behavioral level, the discrimination rate of laughter types was 74.05%. Reaction times were faster for correct responses compared to incorrect response. No significant differences were found for discrimination rate nor the reaction between volition and spontaneous laughter. As for the ERPs, the comparison between social and spontaneous laughter revealed 2 clusters in both tasks. In the passive task, one cluster was found in the right frontal channels (786-868ms) and another one in the left parietal area (801-833ms). For the active task, a similar cluster in the right frontal sensors (898-956ms) was detected as well as one in the right occipital (772-829ms).

Taken together, our findings suggest that discriminating spontaneous and voluntary laughter may be mediated by a component in the late stage of auditory integration. This implies that late processes play a role in distinguishing between volitional and spontaneous laughter, complementing prior research on the topic (Conde et al., 2022) that underscores the necessity of high-level cognitive processes in the discrimination of laughter. Ongoing work involves determining the spatial and spectral dynamics of the neuro-magnetic processes at play during laughter perception

Emotional Perception ¹

EEG/MEG Modeling and Analysis

MEG ²

Perception: Auditory/ Vestibular

Emotions

MEG

Perception