The public defence will be held as a video conference over Zoom.
The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.
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Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.
Digital Trial Lecture – time and place
Adjudication committee
- First opponent: Professor Francis McGlone, Liverpool John Morre University, UK
- Second opponent: Professor Annett Schirmer, The Chinese University of Hong Kong
- Third member and chair of the evaluation committee: Professor Sandip Kanse, University of Oslo
Chair of the Defence
Associate Professor Maja Elstad, Faculty of Medicine, University of Oslo
Principal Supervisor
Professor Uta Sailer, Institute of Basic Medical Sciences, University of Oslo
Summary
Stroking someone’s skin activates a group of slow-conducting, unmyelinated low-threshold mechanoreceptors considered integral in affective behaviour involving touch. These afferent fibres are referred to as C-tactile (CT) fibres and they respond vigorously to slow stroking of the skin at velocities between 1-10 cm/s and the firing of these fibres correlates with the perceived pleasantness of the touch. Moreover, field studies have shown that people become more prosocial and friendly after being touched, however, laboratory studies investigating potential mechanisms are lacking.
This thesis attempted to investigate the psychophysiology of affective touch using a combination of subjective reports and physiological and behavioural responses. In study 1, forty-five participants received touch targeting CT fibres, control touch and a visual control condition and rated the perceived pleasantness and intensity of the stimulation. Skin conductance level was recorded and facial electromyography (EMG) was recorded from two facial muscles related to negative and positive affect. Additionally, we investigated if the participants’ level of prosocial behaviour changed following tactile stimulations using two economic games. In study 2, forty-eight participants received slow stroking touch to the arm at two separate sessions whilst we collected facial EMG and heart rate variability.
Our findings corroborate previous studies that report the pleasantness of CT targeted touch as a hallmark finding. However, although we were able to document consistent and coherent responses to affective touch, touch targeting CT fibres did not change the level of prosocial behaviour when measured in a laboratory setting. A novel finding is that we demonstrated that the activation of the corrugator muscle decreased during CT targeted touch and increased during control touch. We propose that this activation is timed to the arrival of CT afferent input, which can be measured precisely using facial EMG.
Additional information
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