Bursts of regional cortical inhibition during smartphone use

Transient burst of beta (β) oscillations – brief neural events lasting only a fraction of a second – are increasingly recognised for their role in functional inhibition that may support cognitive processes and motor timing underlying goal-directed behaviour. Smartphone behaviour, which involves sustained engagement across diverse cognitive processes provides a fresh avenue to examine these bursts. In this study, we used EEG to measure β-bursts as participants freely interacted with their smartphones using their right hand for ∼ 80 min. Bursts were detected across the scalp, with bilateral sensorimotor electrodes accumulating more periods with bursts than the rest of the electrodes. There was a brain-wide reduction in the probability of bursts preceding a touchscreen touch, followed by an increase, with the strongest modulation in the left sensorimotor electrodes. Interestingly, touchscreen touches sometimes occurred during the bursts. We further examined the intra-burst touch rate across the scalp and found that the rate was lower over the left sensorimotor cortex than the rest of electrodes. Finally, we characterised the diverse behaviours in terms of the interval between touchscreen interactions to find that the behaviours with bursts were typically longer than the behaviours without bursts. We propose that the apparently continuous stream of smartphone touches is supported by brief, spatially localised transient bursts of inhibition. These transients may help support the computational flexibility in distributed neural networks needed for processing continuous motor output and integrating the rich sensory information.