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Section BRAIN-COMPUTER INTERFACES, COGNITIVE NAVIGATION WORKSHOP AND NEUROENGINEERING
Methodological Aspects of Enactive Neurocinema Creation
N.V.Galkina, M.V.Koroleva, V.N.Anisimov, A.O.Luhin
Neurotrend Company, Moscow, Russia. * Presenting e-mail: info@neurotrend.ru
Enactive cinema (EC) is one of the directions of innovative filmmaking. Plot development can be changed depending on the viewers psycho-physiological metrics. The first attempt to create enactive movie was an experimental art project "Obsession" (2005) by Pia Tikka, the filmmaker from Finland. EC technology provides an opportunity to increase emotional influence efficiency of the movie and make it more "environmentally friendly", meaning that the plot can be developed in a more "moderate" way without any stressful details if extremely high emotional reactivity was registered among a greater part of viewers. Both, cardiovascular body reactions metrics, such as heart rate, blood pressure, respiration rate, electrical conductance of the skin etc. [4], and metrics of the bioelectrical activity of the brain [1,2,3,5] can be used as psycho-physiological correlates for objectify emotional reactions (ER) of respondents. However, EEG metrics, frontal asymmetries of alpha-activity in particular, are more appropriate for the fast evaluation of ER dynamics.
Aims
To realize innovative approach in development of EC it is necessary to create the algorithms of relevant psycho-physiological metrics analysis in real time that can be followed by automatic decision in favour of one or another version of the plot.
The aim of the current research was to develop the algorithms of automatic plot development choice, which would cause more relevant state, based on an assessment of the viewers' ER.
Methods
In the pilot study we used three versions of the same video that differ from each other by varying plot fragments, related to specialities of forthe interpretation main part of the video. The shortest version - version 1 has been used as a base. Versions 2 and 3 contained additional fragments, 1 min. 20 sec. and 2 min. respectively. That subsequent fragments specified and expanded the follow plot development.
The plot development choice was made depending on the EEG metrics that were registered during the 2 min. introduction with parameter of alpha-activity asymmetry in frontal areas as an marker of respondent's positive and negative emotions [2,3]. The shortest version of the plot was shown to the respondents when negative emotional state was registered during the introduction, the longest version (v.3) was demonstrated when asymmetry metrics was quite high (confirming positive emotional reaction to the video). Version 2 was shown to the audience with average metrics.
Psycho-physiological metrics registered simultaneously for 5 respondents who were sitting in chairs in the cinema while looking at the same screen. EEG was analysed in real time. Thus, intensity and direction of ER changes for the group in general has been taken into account for the plot choice decisions.
50 respondents participated in the study (27 men and 23 women between the ages of 18 to 50), all right-dominated based on the leading eye and hand.
Results
This study allowed us to reveal relevant psycho-physiological metrics that can be used for evaluation of viewers ER in real time. We also got the control meanings for such metrics which can be used for ER ranking. The group analysis and decision-making algorithms were built that provide an opportunity to choose plot development direction in real time depending on the audience.
References
1. Афтанас Л.И., Рева Н.В., Варламов А.А. и др. Анализ вызванной синхронизации и десинхронизации ЭЭГ при эмоциональной активации у человека: временные и топографические характеристики // Журн. высш. нфвн. деят.- 2003.- Т. 53.- №4.- С.485-494.
2. Aftanas L. I., Golocheikine S. A. Human anterior and frontal midline theta and lower alpha reflect emotionally positive state and internalized attention: high-resolution EEG investigation of meditation //Neuroscience letters. - 2001. - Т. 310. - №. 1. - С. 57-60.
3. Davidson R. J. Anterior cerebral asymmetry and the nature of emotion //Brain and cognition. - 1992. - Т. 20. - №. 1. - С. 125-151.
OM&P
Section BRAIN-COMPUTER INTERFACES, COGNITIVE NAVIGATION WORKSHOP AND NEUROENGINEERING
4. Kreibig S. D. Autonomic nervous system activity in emotion: A review //Biological psychology. - 2010. - T. 84. - №. 3. - C. 394-421.
5. Ravaja N., Somervuori O., Salminen M. Predicting purchase decision: The role of hemispheric asymmetry over the frontal cortex //Journal of Neuroscience, Psychology, and Economics. - 2013. - T. 6. - №. 1. - C. 1.
OM&P
Steady State Visual Evoked Potential Based BCI Study in Overt and Covert Attention
Zafer Iscan1 *, Elena Sokolova2'3, Vadim V. Nikulin1,4
1 Centre for Cognition and Decision Making, National Research University Higher School of Economics, Moscow, Russian Federation;
2 Faculty of Materials Science, Moscow State University, Moscow, Russian Federation ;
3 Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow, Russian Federation;
4 Neurophysics Group, Department of Neurology, Charité - University Medicine Berlin, Berlin, Germany. * Presenting e-mail: zaferiscan@yahoo.com
Introduction
Brain-computer interfaces (BCIs) have potential to help severely disabled people by translation of the intentions of subjects into a number of different commands. Due to its safety and high time resolution, electroencephalogram (EEG) based BCIs have become popular and various designs using different signals (e.g. P300, oscillations) have been proposed. Among them, steady state visual evoked potentials (SSVEPs) are particularly attractive due to their high signal to noise ratio (SNR). In this study, we proposed a four-class BCI design based on SSVEPs to study the differences between the overt and covert attention.
Methods
Four circles with individual flickering frequencies (5.45, 8.57, 12 and 15 Hz) were presented to healthy participants on an LCD monitor. EEG was recorded from 60 channels with three electrooculogram (EOG) channels in 30 trials. In each trial, subjects focused either on the fixation cross or one of the four circles and paid attention to the circle indicated by a red oval frame for three seconds. Decision tree, Naive Bayes and K-Nearest Neighbor classifiers were used to evaluate the classification performance using features generated by canonical correlation analysis.
Results
The offline classification accuracy for the overt attention was positively correlated with the duration of stimuli and was more than 90% when it was longer than two seconds. The accuracy dropped drastically in the covert attention case. Discussion: Classification performance for the overt attention condition validates the robustness of the SSVEP-based BCIs. However, different classification approaches should be developed in order to classify the covert attention responses.
Experimental Measurements of Human Brain Noise Intensity in Perception of Ambiguous Images
Alexander E. Hramov1,2, Vadim V. Grubov1,2, Alexey A. Koronovskii1,2 *, Maria K. Kurovskaya1,2, Anastasiya E. Runnova1,2,Maxim O. Zhuravlev1,2, Alexander N. Pisarchik3,4
1 Saratov State University, Astrakhanskaya, 83, Saratov, 410012, Russia
2 Saratov State Technical University, Politehnicheskaya, 77, Saratov, 410054, Russia;
3 Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato, Mexico;
4 Center for Biomedical Technology, Technical University of Madrid, Campus Montegancedo, 28223 Pozuelo de Alarcon, Madrid, Spain.
* Presenting e-mail: alexey.koronovskii@gmail.com
