Media multitasking advertising slogan

Our research model investigates the following hypotheses:
H1: An atypical (i.e., visual) advertising slogan increases the salience of manipulative intent in media multitasking situations as compared to a typical (i.e, audiovisual) advertising slogan.
H2: The salience of manipulative intent mediates the influence of advertising slogans on consumers’ attitudes toward the brand featured in the ad; increased levels of salience of manipulative intent lead to a decrease in brand attitude.
We simulated a media multitasking situation in a controlled laboratory experiment by asking participants to simultaneously browse an internet website and watch a television program (one-factor (two-level) between-subjects design). The two experimental conditions were created by manipulating the typicality of the TV advertising slogan based on its sensory modality. While the visual slogan represented the atypical condition, the audiovisual slogan was used for the typical condition. A group of 70 non-student participants was obtained through convenience sampling (53% female, Mage = 24.73).
H1 was tested with an ANCOVA (attention allocation used as covariate). H1 and H2 were tested with a mediation analysis (a sensory modality dummy was the independent variable; the salience of manipulative intent was the mediator, and brand attitude the dependent variable; attention allocation served as covariate).