Blink-related oscillations: Neurotechnology advances that open a new window into brain function

Although spontaneous blinking has traditionally not been considered to have much importance in cognition, increasing behavioural evidence suggests that blinking is modulated by changes in attentional demand and cognitive load. BROs (BROs) are neurophysiological responses occurring after blinking, and have been postulated to originate in the precuneus region known to be involved in environmental monitoring and awareness. Given the importance of the precuneus in supporting consciousness and awareness, BRO responses represent a potential avenue for evaluating consciousness in brain-injured patients. However, BRO studies to date have been hindered by major limitations that compromised the reliability of the findings, leading to this response having been largely dismissed by the scientific community. The current doctoral research aims to address this by investigating the potential of utilizing BRO-based measures to evaluate brain function. The first two studies in this research investigated the temporal, spectral, and neuroanatomical features of the BRO response in healthy adults using high-temporal- and high-spatial-resolution MEG, in controlled sensory environments and utilizing multiple task conditions including both resting and cognitive loading via mental calculation. The third study developed a novel signal analysis technique for extraction of BRO responses using only few sensors to enable the development of a point-of-care platform for BRO assessment. Results showed that BRO responses strongly activate the bilateral precuneus and other regions including the dorsal and ventral visual processing pathways as well as regions of the ventral attention network. There are also concomitant spectral effects consistent with sensory, episodic memory, and information processing following blinking. Crucially, results show that BROs are cognitively-driven brain responses, and that spontaneous blink instances actually represent innate ‘stimulus events’ that are actively processed by the brain, with the effects being modulated by cognitive loading. Together, these findings suggest that BRO responses engage key neural processes and activate important cortical hubs, and represent a novel and intriguing new window into brain function.