Friday, 20 October 2017
Dr. Bosiljka Tadić (Department of Theoretical Physics, Jožef Stefan Institute, Ljubljana, Slovenia) was guest at our SCL seminar of the Center for the Study of Complex Systems, on Friday, 20 October 2017.
The talk was entitled:
“Social brain—manifestation of a high-dimensional structure”
Abstract of the talk:
We are our brains (Είμαστε ο εγκέφαλός μας)—the idea originating from Hippocrates becomes increasingly recognized in the era of massive brain imaging and modern science techniques of the data analysis. In recent years, the research activity on brain imaging data considerably increased our knowledge about the fascinating brain functional capabilities, recognizing the brain areas responsible for different activities, information processing, emotions, a comprehension of languages, time, space, numbers, as well as the origin of various diseases. In this context, mapping the imaging data to suitable networks and the use of objective mathematical techniques of graphs theory has provided a significant leap in contemporary science of the brain. Furthermore, the application of Statistical physics to research brain as a complex dynamical system has a long tradition. The problem of the social brain considers the social impact on the brain functions and the neuronal basis of social conduct of individuals. Unlike the single brain imaging, such experiments are rare; they concern simultaneous recordings of a group of people during a particular communication, and the design of an experiment is based on a valid research hypothesis in currently developing science of social neurology and social psychology. The additional complexity of the social brain comes from the fact that it involves areas of the brain hat communicate in a different way, depending on the type of inputs and their precise content (emotional and cognitive).
In this Seminar, based on our recent work , we will present the main concepts and results of our analysis of a set of EEG empirical data recorded in a group of people during spoken communications. Mapping the aggregate data on multi-brain networks, we use methods of algebraic topology of graphs to investigate functional brain connections that underly the social brain of the participants. These mathematical techniques identify the basic geometric descriptors such as triangles, tetrahedrons and cliques of higher orders, as well as the ways in which they assemble to form the complex multi-brain graph structure. Interestingly, our analysis reveals how the occurrence of these higher organized geometries of inter-brain networks correlates with the listener’s self-reported quality of coordination with the speakers. Moreover, these methods can detect shifts in the brain activity pattern arising from the changes of the subject or other impact on the individual.
 B. Tadić, M. Andjelković, B. M. Boškoska, Z. Levnajić, Algebraic topology of multi-brain connectivity networks reveals dissimilarity in functional brain patterns during spoken communications, PLOS one 11, e0166787 (2016)