Corticospinal Excitability During Action Observation: A TMS Study of Digital Natives and Digital Immigrants

Individuals born into a fully digital world, termed Digital Natives (DN), have accumulated years of intensive two-thumb smartphone typing experience during developmentally sensitive periods, in contrast to Digital Immigrants (DI), who adopted technologies only in adulthood. This difference in sensorimotor history may produce distinct motor representations of smartphone typing, with potential consequences for how each group processes observed digital actions. The mirror neuron system is known to be calibrated by the observer’s own motor repertoire, with richer sensorimotor experience producing stronger corticospinal facilitation during action observation. The present study investigated two primary questions: first, whether observing smartphone typing elicits corticospinal facilitation, measured through motor-evoked potential (MEP) amplitudes recorded from the Opponens Pollicis (OP) muscle using single-pulse TMS; second, whether this facilitation is influenced by the observer’s sensorimotor expertise relative to the demonstrator, specifically whether Digital Native (DN) observers show greater corticospinal excitability when observing DN typing compared to Digital Immigrant (DI) typing. Thirty-seven right-handed DN participants observed video stimuli depicting smartphone typing performed by four demonstrators (two DN and two DI) while TMS pulses were delivered to activate the Opponens Pollicis muscle. Z-scored MEP amplitudes from thirty-five participants (following exclusions) were analysed using a 2 × 2 repeated-measures ANOVA with Group (DN vs. DI) and Gender (Female vs. Male) as factors, while baseline-normalised MEP ratio scores were used to assess corticospinal facilitation relative to rest. Observing smartphone typing produced significant corticospinal facilitation above baseline across all conditions (all ps < .001), confirming robust motor resonance for digital hand actions. However, no significant effects of demonstrator group or gender emerged. Although non-significant, DN demonstrators elicited slightly higher corticospinal excitability than DI demonstrators, following a pattern directionally consistent with predictions. These findings provide evidence that observing smartphone typing engages the human motor system similarly to other goal-directed actions. While expertise-dependent modulation was not statistically confirmed, the results suggest that shared digital motor experience may influence the neural processing of observed digital actions, providing a foundation for future research and potential applications in the domain of social cognition and clinical settings.