Media Multitasking and Cognitive Control: Small Linear Associations and No Evidence for an Inverted-U Relationship Across Seven Behavioral Paradigms

Background: Heavy media multitasking has been linked to poorer cognitive control, but findings are heterogeneous, and claims of an inverted-U relationship have rarely been tested with methods that establish curve shape. Methods: Using a publicly available dataset, we analyzed 278 adults who completed up to seven cognitive-control paradigms (219 completed all seven), yielding nine behavioral outcomes. The Media Multitasking Index (MMI) was treated as continuous. Linear and quadratic regressions were complemented by two-lines tests and restricted cubic splines for every outcome, and equivalence tests and Bayes factors quantified evidence for the null. Results: MMI showed a small negative linear association with cognitive control capacity and a small positive association with conflict-resolution efficiency; the latter was sensitive to the exclusion criterion. No outcome met the two-lines criterion for a U-shaped or inverted-U relationship. Reactive control showed curvature, but performance did not increase reliably at moderate MMI levels and declined at higher levels. Six of nine outcomes were statistically equivalent to zero (|r| < 0.20), with Bayes factors of 6.82–18.67 favoring the null. Conclusions: Associations between media multitasking and cognitive control are small, and an inverted-U relationship was not supported when curve shape was tested directly.