Investigating real-life emotions in romantic couples: a mobile EEG study

Abstract

The neural basis of emotional processing has been largely investigated in constrained spatial environments such as stationary EEGs or fMRI scanners using highly artificial stimuli like standardized pictures depicting emotional scenes. Typically, such standardized experiments have low ecological validity and it remains unclear whether their results reflect neuronal processing in real-life affective situations at all. Critically, emotional situations do not only encompass the perception of emotions, but also behavioral components associated with them. In this study, we aimed to investigate real-life emotions by recording couples in their homes using mobile EEG technology during embracing, kissing and emotional speech. We focused on asymmetries in affective processing as emotions have been demonstrated to be strongly lateralized in the brain. We found higher alpha and beta power asymmetry during kissing and embracing on frontal electrodes during emotional kisses and speech compared to a neutral control condition indicative of stronger left-hemispheric activation. In contrast, we found lower alpha power asymmetry at parieto-occipital electrode sites in the emotional compared to the neutral condition indicative of stronger right-hemispheric activation. Our findings are in line with models of emotional lateralization that postulate a valence-specific processing over frontal cortices and right-hemispheric dominance in emotional processing in parieto-occipital regions. Overall, we could thus support theories of emotional asymmetries which suggest that affective processing is not uniformly lateralized across the brain using a highly ecologically valid paradigm.

A short review on emotion processing: a lateralized network of neuronal networks

“…Analysis of alpha-band electroencephalographic activity in the frontal lobe revealed that stimuli designed to induce happiness elicit a greater cortical activity the left hemisphere, whereas stimuli designed to evoke negative emotions resulted in a greater cortical activity in the right hemisphere (Jones and Fox 1992;Zhao et al 2018). A recent study addressing the ecological validity of the valence lateralization hypothesis by means of a mobile EEG recording system to monitor brain activity of romantic partners in their everyday environment also found emotional kisses to be associated with an increased asymmetry index in alphaband activity of the frontal lobe (Packheiser et al 2021).…”

“…Reports on functional lateralization date back as early as 1861, when Broca associated a lesion in the third convolution of the left frontal lobe with the patient's sudden loss of the ability to speak (Broca 1861a;b). Besides the richly documented asymmetry associated with speech production and language comprehension (Friederici and Gierhan 2013), lateralization has also been described for functions as varied motor control (Amunts et al 1997;Sainburg et al 2016;Sokolowska, 2021), visuospatial skills (Ciricugno et al 2021;Vogel et al 2003), and emotion processing (Demaree et al 2005;Packheiser et al 2021), to name only a few of many studies.…”

Towards real-world neuroscience using mobile EEG and augmented reality

“…Mobile whole-head EEG applications have made great strides in the past decade, recently being applied to study memory (Griffiths et al, 2016; Park & Donaldson, 2019; Piñeyro Salvidegoitia et al, 2019), emotion (Packheiser et al, 2021; Soto et al, 2018), attention (Ladouce et al, 2019; Liebherr et al, 2021) and movement (Mustile et al, 2021; Packheiser et al, 2020; Reiser et al, 2021) in complex real-world settings. Advances in hardware and software have made fully mobile high-density EEG a useful tool for cognitive neuroscience (Klug & Gramann, 2021; Symeonidou et al, 2018), however, what remains problematic is the ability to flexibly manipulate key variables, as now our cognitive variables of interest are part of the real world.…”