EEG CORRELATES OF HUMAN-RHYTHM INTERACTION DEPARTMENT OF INFORMATION TECHNOLOGY, WAVES Wannes Van Ransbeeck, Dick Botteldooren, Sarah Verhulst, Marc Leman The scene Within the metaverse a tendency exists towards a seamless and intuitive interaction in the virtual world by an immersive and interactive environment. Capturing user sensation and experience during the interaction can help to build and maintain this immersion in any interaction or context, including music and rhythm. Furthermore, it may extend or improve an interaction into creating a lasting meaningful interaction. Besides physical user inputs or pupillometry, the brain shines a relevant light on this interaction. Hence brain monitoring and bio-synchronization can be a relevant tool for user analysis of the experience. The issue The main techniques used for neural analysis in relation to music perception and experience encompass two fields being frequency tagging and phase synchronisation. The former deals with the manifestation of the stimuli frequencies while the latter considers band activity as it synchronised to presented rhythms and its prolonged continuation. The syncing of brain, neural entrainment as you will, has opened a lot of research into evaluating rhythm and music perception, prediction and also the evoked emotion. However, despite being a topic of major interest in neuroscience, correct non-invasive quantification of this entrainment seems difficult. Especially when it comes to defining the emotion, experience and sensation without providing misinterpretation [1]. A fundamental linkage between user experience, interaction and neural markers has still not been fully explored and pilot data of a suggested approach is presented here. Plan Pilot data and experiment setup are presented in this poster. This aimed at exploring potential brain markers in relation to synchronicity of a performance and associated questionnaire responses to identify bio- indicators of a good human-rhythm interaction and through it identify entrainment and user experience. Figure 1: Illustration of band activity fluctuation for 6 beats and 3 taps. Setup A finger-taping experiment with variable beat patterns will be conducted on a cohort of 15 subjects, in which a subject synchronizes its tapping to the auditory presented rhythm or a variation of it. The accompanying auditory rhythm can be either a binary, ternary or metronome rhythm in a 6 beat measure controlled by a computer or second participant. The subject will either perform the binary or ternary rhythm. During the synchronization both spectral band activity and the low rhythm-frequency content of the EEG activity will be evaluated locally in time and across the experiment. Two spatial filters, based on localizer trials, will allow separation of sensorimotor and perceptual activity to study their response separately. The quality of the rhythm interaction quality is defined on the basis of the physical performance (mean asynchrony and resultant vector), questionnaires and additionally builds on the theory of human embodiment within music interaction. Figure 2: Spectral activity at stimulation frequencies for 2 beats and 3 taps (polyrhythm), for motor components (MOT IC3) and auditory responses(AUD IC16) as well as individual electrodes. Figure 3: Localiser for motor (left) and auditory(right) activity. Figure 4: Illustration of location of stimulation frequency in the brain. Results & Discussion Initial analysis was conducted and allowed extraction of both spectral band activity in windows around tapping instances (Figure 1), frequency activity across the entire experiment at stimulation frequencies (Figure 2), localizer data on separate motor and auditory components (Figure 3) and identification of frequency specific activation regions in the brain (Figure 4). Spectral influence of the sphere visualization illustrated clear effects on spectral content at stimulation frequencies and accuracy throughout the experiment prov