Spatiotemporal Profiles of Brain Activation During Learning and Strategy Formulation

How do humans learn complex visuomotor tasks with a strategic component? We explore this question in the context of the Naval Research Laboratories Navigation Task that is used for selecting and training future submarine pilots. About 50% of participants fail to achieve the desired competence level on the task, even after a large number of trials. A central question in this project is whether we can analyze learning failures rapidly enough to intervene during training. To this end, we set out to identify a neural signature of strategy formulation by adopting a system-of-systems approach to dynamically track the learning state of a subject using measurements of brain activity and coordinated visuomotor actions throughout the learning process. We analyzed the spatiotemporal profiles of brain activation using a coherence measure and interpreted them based on the visuomotor performance data. Our results show the presence of long-range synchronies in the gamma band of brain activity in subjects who successfully formulate a strategy for the task and suggest a tight cooperation between occipital and frontal brain regions. These long-range synchronies are absent in lower frequencies. Subjects who lack this pattern fail to devise an appropriate strategy, a fact confirmed by the analysis of their visuomotor performance data. The absence or presence of long-range synchronies in the gamma band can be detected fairly early during the learning process and, therefore, our method can be used to identify learning difficulties that would require appropriate intervention based on neural signatures of strategy formulation.