Smartphone behavior is suppressed during bursts of wake slow waves

Abstract

Real-world behavior unfolds as a continuous flow of actions over time. One possibility is that this continuous flow is enabled by a seamless stream of cortical activity. However, emerging evidence suggests that even during ongoing behaviors, cortical neural populations undergo brief periods of silence. This off-state can be detected as wake slow waves in EEG, similar to the slow waves characterizing deep sleep. Here, we leveraged the spontaneously occurring fluctuations in smartphone touchscreen interactions in combination with EEG to investigate the dynamics of slow waves during behavior. We find that slow waves occur in bursts - characterized by short consecutive intervals - interleaved with longer periods of absent slow waves. During smartphone use, the probability of bursts increased compared to rest, and the duration of burst-absent periods was lower. During the bursts, however, the likelihood of generating smartphone interactions was substantially diminished. Conversely, the periods of absent slow waves were more permissive to the behavioral output. We propose that slow wave burst dynamics are state-dependent, configured to create temporal windows permissive to action generation. This configuration, in turn, allows behavioral outputs to leverage the windows of opportunity that emerge between slow wave bursts. Our study, combining smartphone behavior with EEG, reveals how brief cortical silencing events structure the computations underlying everyday actions.