Multimodal attention in a simulated driving environment - Novel approaches to the quantification of attention based on brain activity

Abstract

The concept of attention is an established focus of study in neurosciences. The quantification of attention during driving can help identify situations in which the driver is not completely aware of the situation. This work deals with the implementation of a setup to simulate a driving environment that enables audiovisual tasks to be embedded into the driving task while acquiring biosignals such as electroencephalography. The main goal of this dissertation was to find a correlation between attention and brain activity as seen on the electroencephalographic activity while driving. By using the principle of phase-amplitude coupling in electroencephalographic signals, it was hypothesized that Theta-Gamma phase-amplitude coupling might correlate to multimodal attention and thus might be eligible as a biomarker of attention in tasks such as driving. Surface electroencephalography was measured simultaneously in drivers and copilots while participating in simulated driving scenarios with varying multimodal attentional demands. The phase-amplitude coupling between Theta-band phase and Gamma-band amplitude from the electroencephalograpic signal was obtained and evaluated. Results showed significant phase-amplitude coupling differences between drivers and copilots in areas related to multimodal attention (prefrontal cortex, frontal eye fields, primary motor cortex, and visual cortex). The results were confirmed by behavioral data acquired during the test (detection task). We conclude that phase-amplitude coupling does function as a biomarker for attentional demand by detecting cortical areas being activated through specific multimodal (in this case, driving) tasks. Additionally, the data acquired in the main work of this thesis was used to test an auditory stimulus reconstruction algorithm previously tested by our work group. The stimulus reconstruction allowed to obtain post-hoc additional information regarding attentional effort during driving (success of the stimulus reconstruction was significantly correlated to auditory effort) and serves as a compliment to the main results. This dissertation thus offers an insight on attentional systems in multimodal situations and the neurophysiological systems underlying attention. It develops methods to measure attention in a driving environment, both as seen using phase-amplitude coupling and by being able to single out auditory effort by reconstructing the auditory stimuli. Finally, these methods can be translated to other activities since they are both based on non-invasive electroencephalography.