Mindfulness and Attention: Current State-of-Affairs and Future Considerations

Abstract

This review examines longitudinal studies of changes in components of attention following mindfulness training. A total of 57 retreat studies, non-randomized trials, and randomized controlled trials were identified. Employing the classical taxonomy proposed by Posner and Petersen (1990), outcome measures were broadly categorized based on whether they involved maintenance of an aroused state (alerting), selective prioritization of attention to target items (orienting), or assessed conflict monitoring (executive attention). Although many non-randomized and retreat studies provide promising evidence of gains in both alerting and conflict monitoring following mindfulness training, evidence from randomized controlled trials, especially those involving active control comparison groups, is more mixed. This review calls attention to the urgent need in our field of contemplative sciences to adopt the methodological rigor necessary for establishing mindfulness meditation as an effective cognitive rehabilitation tool. Although studies including wait-listed control comparisons were fruitful in providing initial feasibility data and pre-post effect sizes, there is a pressing need to employ standards that have been heavily advocated for in the broader cognitive and physical training literatures. Critically, inclusion of active comparison groups and explicit attention to the reduction of demand characteristics are needed to disentangle the effects of placebo from treatment. Further, detailed protocols for mindfulness and control groups and examination of theoretically guided outcome variables with established metrics for reliability and validity are key ingredients in the systematic study of mindfulness meditation. Adoption of such methodological rigor will allow for causal claims supporting mindfulness training as an efficacious treatment modality for cognitive rehabilitation and enhancement.

Keywords: attention; meditation; mindfulness; rigorous randomized controlled trials.

Figure 1.

Presents the search results using the PRISMA flowchart.

Figure 2.

Study design characteristics of longitudinal studies of mindfulness training. Spheres represent existing longitudinal training studies examining the impact of mindfulness training on facets of attention (labeled with their study numbers as listed in Table 1 (A-C)). Concentric layers are used to denote the presence of the first four study design issues discussed in the manuscript. The clustered “pearls of wisdom” denote studies that followed CONSORT guidelines.

Figure 3.

Results of mindfulness training studies on attention separated by study design characteristic. For each characteristic, separate bars represent studies that did (“Yes”, opaque colors) and did not (“No”, faded colors) employ each characteristic. Studies finding benefits of mindfulness for one or more measures of attention are shown in green (“Favorable”). For RCTs this refers to differential improvements in the mindfulness group compared to control groups, but for retreat studies and non-randomized studies, where no control group was employed, this includes pre-post improvements within the mindfulness group or where control participants were included, differential improvements compared to controls. Studies finding no significant effect of mindfulness training on attention or equivalent performance between the mindfulness and the control group at post-training are shown in blue (“No Effect”) and those finding a benefit for a control group over mindfulness training are shown in red (“Unfavorable”). The percentage of studies with each result are indicated within the bars, calculated separately for studies that did and did not employ each design characteristic.