Research
Thesis Defense

Lise Hobeika's PhD Defense

November 29,
2 p.m.- 5:30 p.m.
Ircam
salle Stravinsky

Lise Hobeika will defend his doctoral thesis carried out at IRCAM in the Acoustic and Cognitive Spaces team (STMS - CNRS/IRCAM/UPMC):
"Interplay between multisensory integration and social interaction in auditory space: towards an integrative neuroscience approach of proxemics"

Abstract

The space near the body, called peripersonal space (PPS), was originally stud- ied in social psychology and anthropology as an important factor in interpersonal communication. It was later described by neurophysiological studies in monkeys as a space mapped with multisensory neurons. Those neurons discharge only when events are occurring near the body (be it tactile, visual or audio information), delineating the space that people consider as belonging to them. The human brain also codes events that are near the body differently from those that are farther away. This dedicated brain function is critical to interact satisfactorily with the external world, be it for defending oneself or to reach objects of interest. However, little is known about how this function is impacted by real social interactions. In this work, we have conducted several studies aiming at understanding the factors that contribute to the permeability and adaptive aspects of PPS.

A first study examined lateral PPS for individuals in isolation, by measuring re- action time to tactile stimuli when an irrelevant sound is looming towards the body of the individual. It revealed an anisotropy of reaction time across hemispaces, that we could link to handedness. A second study explored the modulations of PPS in social contexts. It was found that minimal social instructions could influence the shape of peripersonal space, with a complex modification of behaviors in collaborative tasks that outreaches the handedness effect. The third study is a methodological investi- gation attempting to go beyond the limitations of the behavioral methods measuring PPS, and proposing a new direction to assess how stimuli coming towards the body are integrated according to their distance and the multisensory context in which they are processed.

Taken together, our work emphasizes the importance of investigating multisen- sory integration in 3D space around the body to fully capture PPS mechanisms, and the potential impacts of social factors on low-level multisensory processes. Moreover, this research provides evidence that neurocognitive social investigations, in particu- lar on space perception, benefit from going beyond the traditional isolated individual protocols towards actual live social interactive paradigms.

Jury

Ana Tajadura-Jiménez, Research Fellow at the Universidad Carlos III de Madrid, Spain, Rapporteur
Stefan Glasauer, University Professor at Ludwig-Maximilian University Munich, Germany, Rapporteur
Guenther Knoblich, University Professor at Central European University, Hungary, Examinateur
Malika Auvray, Chargée de Recherche, CNRS, France, Examinateur
Giandomenico Iannetti, University Professor at University College of London, UK, Examinateur
Isabelle Viaud-Delmon, Directrice de Recherche, CNRS, France, Directeur de thèse