Multiple studies have shown mindfulness to be an effective tool in reducing mind-wandering. Some studies define mindfulness purely as maintaining awareness of the present moment, while others also include nonjudgement, or acceptance, in their definition of mindfulness. Because of this variability among studies in terms of how mindfulness is operationally defined, there have been mixed results among studies regarding the role of acceptance in mindfulness training for mind-wandering. However, work by Teper (2013) suggests that acceptance—in addition to mindful awareness—contributes to the efficacy of mindfulness through its effect on executive functioning (e.g., inhibition). We hypothesized that receiving acceptance-enhanced mindfulness training would reduce mind-wandering and increase inhibitory control compared to mindfulness training without acceptance and compared to an active control group.

Our final sample included n = 92 individuals who were divided into three groups: acceptance-enhanced mindfulness training, mindfulness training without acceptance, and a control condition. Due to disruptions from COVID-19, the study was conducted through an online study platform (Inquisit, 2021). Four mixed-methods 3 x 2 ANOVAs were run examining the effect of training type on each of the mind-wandering and inhibition variables at two timepoints.

There was no effect of training type on any of the main dependent variables, though there was an effect of time for some variables.

Limitations of the online study format are discussed in regard to their potential contributions to null results. Topics for future research and the implications for study design are considered.