Modulation of Mind Wandering Using Monaural Beat Stimulation in Subjects With High Trait-Level Mind Wandering

Abstract

Mind wandering (MW) refers to a state when attention shifts from the task at hand or current situation toward thoughts, feelings, and imaginations. This state is often accompanied by a decline in mood, and patients suffering from major depression exhibit more perseverative MW. Hence, although the directionality of the relationship between mood and MW is still under investigation, it may be useful to explore possible avenues to reduce MW. In an earlier pilot study, we investigated MW during auditory beat stimulation in healthy subjects using thought-probes during a sustained attention to response task (SART). We found evidence for reduced MW during monaural 5 Hz beats compared to silence, sine tones, and binaural 5 Hz beats. Moreover, the data tentatively suggested that this reduction was particularly pronounced in subjects with high levels of MW during silence. In the current study, we therefore asked whether MW can be reduced by monaural theta beats in subjects with high trait-levels of MW, as indicated by an online MW questionnaire. Preselected subjects performed a SART task with thought-probes assessing the propensity to mind wander, meta-awareness, and the temporal orientation of MW. Stimulation conditions comprised monaural theta beats, as well as silence (headphones on), and sine tones as control conditions. Our main hypothesis stating that the propensity to mind wander during monaural theta beats is reduced compared to both control conditions was only partly confirmed. Indeed, MW was significantly diminished during exposure to the theta beats compared to sine tones. However, reduced MW during theta beats versus silence was only observed in a subgroup using stricter inclusion criteria. Considering possible reasons for this outcome, our data suggest that the preselection procedure was suboptimal and that beat effects are modulated by the individual responses to auditory stimulation in general.

Side effects of monaural beat stimulation during sustained mental work on mind wandering and performance measures

“…While we found evidence for a modulation of MW propensity due to monaural beat stimulation in our previous studies (Chaieb et al, 2020(Chaieb et al, , 2022b, we did not observe such an effect in our current study. Differences in study design and methodology might account for this discrepancy.…”

“…Moreover, modulation rates of the monaural beat stimuli were continuously shifted between 4 and 8 Hz to render the beat stimuli less monotonous. Furthermore, the lengths of SART blocks were shorter in the present study (around 15 min) than in Chaieb et al (2020;around 30 min) and Chaieb et al (2022b;around 35 min), which may also have affected the outcome. In this context, we recently reported that the temporal evolution of MW characteristics during SART blocks may depend on auditory stimulation conditions (Chaieb and Fell, 2023).…”

“…However, most participants identified as female in the present study. In Chaieb et al (2022b) subjects were preselected for high scores of the MW questionnaire (indicating high trait MW) (Mrazek et al, 2013). Moreover, modulation rates of the monaural beat stimuli were continuously shifted between 4 and 8 Hz to render the beat stimuli less monotonous.…”

“…We observed tentative evidence for decreased MW during monaural 5 Hz beats compared to binaural 5 Hz beats, silence, and sine wave stimulation. In a follow-up study (Chaieb et al, 2022b), monaural theta beats with shifting modulation frequencies (4-8 Hz) were employed, with subjects preselected for high MW traits based on MW questionnaire scores (Mrazek et al, 2013). Findings of this study pointed to a beat-related reduction of MW compared to sine waves and silence, in subjects with high trait levels of MW.…”

“…In the present study, we therefore used visual-analog scales to assess the subjective perception of the stimulation conditions (distracting, disturbing, uncomfortable, tiring), as well as changes of anxiety, stress and negative mood after versus before stimulation. To enable evaluation of the influence of trait levels of MW (Chaieb et al, 2022b), subjects completed two wellestablished MW questionnaires (Mrazek et al, 2013;Mowlem et al, 2019). Aside from 5 Hz monaural beats, we also implemented a condition in which subjects were free to choose a modulation frequency in the theta range (range of choices: 3.5/4/4.5/5/5.5/6/6.5 Hz).…”