Cortex-wide alignment to the temporal structure of smartphone interactions

Smartphones are used for different purposes, with each touchscreen interaction (taps and swipes) shaped by a distinct combination of cognitive, affective, and environmental factors. Given this uniqueness of each interaction, it would seem reasonable to treat one interaction as independent from another. Yet, emerging evidence suggests the opposite: when smartphone interactions are analyzed based on their inter-interaction interval properties, they reveal structured patterns and point to common underlying processes linking distinct interactions. To address the possibility of common neural processes underlying distinct interactions, we recorded EEG signals during hour-long smartphone use sessions spanning various activities (n = 53 participants, accumulating 136,869 taps). We tracked the next-interval property of each interaction in a two-dimensional behavioral map spanning 100 ms to 10 s. Independent component analysis of the EEG signals identified twelve broad neural signal sources. The neural signals time-locked to touchscreen interactions organized into clusters across the behavioral map, with neighboring locations sharing common neural sources and timing patterns. These clusters differed across individuals but were generally more pronounced in the signals preceding the touchscreen interaction than those following it, suggesting individualized neural strategies for planning and executing sequential smartphone interactions. Our findings show that neural processes are systematically organized according to a behavioral map derived from the temporal dynamics of short action sequences. We propose that this organization allows the brain to efficiently allocate neural resources through a low-dimensional representation of real-world behavioral dynamics.