Media multitasking enhances individuals' anticipatory brain functions.

Media multitasking has become pervasive in our daily lives, yet its impact on cognitive abilities remains contentious, with more evidence supporting adverse effects (scattered attention hypothesis) than benefits (trained attention hypothesis). Recent studies have increasingly focused on the training effects of behavioral training on anticipatory brain functions, which involve cognitive and motor preparation before stimulus onset, assessed using event-related potentials (ERPs). This study investigated whether media multitasking enhances anticipatory brain functions and how task difficulty influences this relationship. Participants performed a response discrimination task where they detected targets among distractors, with salient and nonsalient targets manipulating task difficulty. Behavioral results indicated faster response times and comparable accuracy in heavy media multitaskers (HMM) compared to light media multitaskers (LMM) across both salient and nonsalient conditions, suggesting that media multitasking can expedite responses without sacrificing accuracy. The larger Bereitschaftspotential (BP) amplitude observed in HMM compared to LMM reflects heightened motor preparation in HMM, consistent with their quicker responses. The larger prefrontal negativity (pN) and P3 amplitudes in the nonsalient condition for HMM indicate increased cognitive preparation before stimulus onset and heightened attention control after stimulus onset. Our results suggest that HMM can flexibly adjust resource allocation based on task demands to maintain their response speed advantage. These findings suggest that LMM may possess a relatively steady acceleration/brake system, whereas HMM exhibit a more adaptable system capable of responding flexibly to diverse situations. Overall, these results underscore the training effects of media multitasking on anticipatory brain functions, supporting the trained attention hypothesis.