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A real-time, online study of the functions of consciousness

Periodic Reporting for period 1 - Consciousness online (A real-time, online study of the functions of consciousness)

Reporting period: 2015-06-01 to 2017-05-31

What – if any – is the functional significance of conscious awareness? Even after centuries of theoretical effort and decades of experimental research, the answer to this question is still unknown, partly due to conceptual and methodological limitations of previous approaches. In this action, I proposed a novel approach that addresses this fundamental psychological question by capitalizing on neuroscientific development. I planned to construct a real-time system that analyzes intracranial and EEG data and presents it to the subject as sensory feedback. I suggested to train the system to detect unconscious neural events as they unfold, and present them to the subject online, hereby turning these unconscious events into consciously accessible ones. The effect of this manipulation on performance could then be measured, revealing the unique contribution of consciousness to the function of interest. This proposal included four experiments that focus on consciousness’ involvement in volitional control, using the Binocular Rivalry paradigm (BR). In BR, subjects' perception alternates between two stimuli presented simultaneously but separately to each eye. This promised to yield new insights about the widely-debated role of consciousness in volitional control while paving the way to a systematic, innovative investigation of the possible functions of consciousness.
At the end of the two-years period assigned for this project, we still haven’t managed to establish such a real-time system, but we obtained insightful data about the dynamics of binocular rivalry, both using intracranial data and EEG recordings. Below I explain these and describe our achievements so far in greater detail. This will hopefully pave the way for future applications of the realtime system paradigm, as well as substantially advance our understanding of consciousness, its underlying mechanisms and its functions.
In the last two years, we made substantial progress in identifying the underlying neural mechanisms of Binocular Rivalry (BR) and the attempts to control its dynamics, both with intracranial data and with EEG – in line with the proposed research plan. The intracranial part of the project turned out to be highly complicated; our first step was to reanalyze the data we already obtained from five patients, which entailed extensive training and modifications of previous analysis codes to our needs. In addition, we gathered data from three new patients, leading to a total of eight. Analyzing these data yielded interesting results, including a special class of neurons which are instruction-sensitive, so that they change their firing patterns according to subjects’ volitional efforts. Yet our units-yield was lower than expected, and some of the activations were not as strong as we hoped for, making it unlikely that they would suffice for a realtime system and online feedback. Thus, we decided to join forces with another MSCA awardee, Dr. Hagar Gelbard Sagiv, who has been working on a similar project, yet with a somewhat different approach. There, using selective responses rather than categorical ones, we identified much stronger activations, starting as early as 2s prior to the perceptual switch. We have just submitted a manuscript reporting our results. This constitutes an important contribution to our understanding of consciousness and its underlying mechanisms, as reflected in BR dynamics, and might also pave the way for the online realtime project originally suggested in this action. The EEG study was completed as planned, and is now being finalized as well; we are at the final stages of the analysis, and the results corroborate and complement those of the intracranial project, showing early activations which precede the switch, as well as differential responses which are instruction-selective, like some of the neurons we found. We anticipate submitting the manuscript in the next few months. Two additional papers were accepted for publication, addressing questions which fall under the umbrella of the main research question (yet tackle it in different ways than the ones which were originally planned).
This research is a classical basic science one, and accordingly it does not have any social-economic impact or wider societal implications. Yet it does progress the state of the art in our understanding of the mechanisms underlying human conscious perception, and more specifically – the single unit and EEG correlates of perceptual switches during binocular rivalry. It further sheds light on the processes by which attention influences rivalry. Hopefully, this will help us develop novel techniques in line with the proposed research, which in turn will allow us to take a necessary step towards a better understanding of consciousness and its functions.
Results of the EEG study