Modulation of functional connectivity using neurofeedback and its effects on behaviour

Abstract

The brain is composed of several functionally specialized areas. Communication between these brain regions serves as the main substrate for complex cognitive processes and behaviours that require a continuous integration of information. The kind of interaction concluding between disparate brain regions both, time-locked to, or independent of external events can be indexed by functional communication. There is abundance of literature suggesting the modulation of the underlying functional communication between different brain regions by manipulating the behaviour i.e. different variations in motor tasks and cognitive tasks. But, the outcome of all these studies only suggests the correlative nature of the task induced functional communication without suggesting the causal relation. In the presented dissertation, we have trained healthy participant to volitionally modulate their functional connectivity between the target brain regions using real-time magnetoencephalography neurofeedback (rt-MEG Neurofeedback) and assessed its effects on behavioural outcome. Together with literature reports, our result hint towards a causal relationship between changes of functional connectivity and changes in perceptual and behavioural performance. In the first study, 30 healthy participants learned to modulate their functional connectivity between primary motor cortices using real-time neurofeedback. Effects of the training on the behavioural outcome was assessed by investigating their motor performance prior and after the training. We conclude from this study that the increase of the functional communication between the two primary motor cortices results in the deterioration of the motor performance in a bimanual finger tapping task. In the second study, 8 healthy participants learned to modulate their fronto-parietal communication using a ViBM paradigm in neurofeedback setup. Effect of the training on the perceptual threshold were assessed. We demonstrated that the modulation of the fronto-parietal communication is feasible and does influence participants’ perceptual thresholds suggesting that the improvement in the fronto-parietal communication does reduce the perceptual threshold measured before (Pre-test) and after (Post-test) the neurofeedback training. This doctoral dissertation provides evidence supporting a causal relation between the modulation of functional connectivity and behaviour and perception and thus provides new insights in the intra-cortical communication and thus in the hierarchical organization of the human brain.