Chapter 14 - Mindfulness training as cognitive training in high-demand cohorts: An initial study in elite military servicemembers

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Abstract

Cognitive ability is a key selection criterion for entry into many elite professions. Herein, we investigate whether mindfulness training (MT) can enhance cognitive performance in elite military forces. The cognitive effects of a short-form 8-h MT program contextualized for military cohorts, referred to as Mindfulness-Based Attention Training (MBAT), were assessed. Servicemembers received either a 2-week (n = 40) or 4-week (n = 36) version of MBAT or no training (NTC, n = 44). Sustained attention and working memory task performance along with self-reported cognitive failures were assessed at study onset (T1) and 8-weeks later (T2). In contrast to both the NTC and 2-week MT groups, the 4-week MT group significantly improved over time on attention and working memory outcome measures. Among the 4-week more so than the 2-week MBAT participants, working memory performance improvements were correlated with their amount of out-of-class MT practice. In addition to these group-wise effects, all participants receiving MBAT decreased in their self-reported cognitive failures from T1 to T2. Importantly, none of these improvements were related to self-reported task motivation. Together, these results suggest that short-form MT, when delivered over a 4-week delivery schedule, may be an effective cognitive training tool in elite military cohorts.

Introduction

Attention and working memory are cognitive abilities necessary for complex fluid behavior. Whereas attention involves the selection and privileged processing of a subset of available information, working memory allows for the maintenance and manipulation of selected information over short intervals (see Jha, 2002). These cognitive processes are critical for efficient and successful performance. Yet, attentional lapses are frequent and performance errors commonly occur. One compelling context in which cognitive failures may have life or death consequences is during military operations. Lapses of attention during security screening or watch-standing, or failures of working memory in tasks with high workloads, such as operating modern military weapons or aircraft, for example, could lead to death and devastation on a grand scale. Although the value of promoting peak cognitive functioning for such contexts is obvious, successful routes to do so have not been fully investigated (see Blacker et al., 2018). Nonetheless, the field of cognitive neuroscience has been keen to examine if and how such cognitive abilities may be strengthened via training (see Simons et al., 2016).

Special operations forces (SOF) from militaries around the world are tasked with some of the most physically and cognitively demanding military missions. To best ensure their mission success, SOF personnel undergo a rigorous selection process based, in part, on their “cognitive ability domain” (see NATO, 2012). Beyond selection, there has been recent interest in cognitive training approaches to optimize cognitive abilities in such forces. A recent article reported in the Journal of Special Operations Medicine suggested that application of mindfulness skills, cultivated by engagement in mindfulness training (MT) programs, may be one route by which cognitive abilities can be augmented in the service of mission-related tasks (Deuster and Schoomaker, 2015).

Mindfulness skills can be used for a multitude of mission-related activities. Agile and adaptive reasoning, which is required for mission planning and execution, surely can benefit from improvements in attentiveness and the working memory of factors influencing selection of the best course of action among a multitude of choices. (Deuster and Schoomaker, 2015, p. 95)

Herein, we describe an initial feasibility and effectiveness study (see Bowen et al., 2009) of MT as a form of cognitive training in SOF cohorts. Our overarching goal is to evaluate whether MT has salutary cognitive effects in such elite military cohorts. If so, it may be fruitful to consider its use as a cognitive enhancement tool in other highly skilled and elite professions in civilian contexts, or more broadly in highly demanding but routine settings. In the service of motivating the specific research questions of the present study, prior studies examining cognitive vulnerabilities suffered by those in high-demand circumstances, as well as prior results from cognitive training studies, including those involving MT, are discussed below.

Military operations conducted by conventional forces and SOF routinely place consequential and life-threatening demands on finite cognitive abilities. Attentional lapses and cognitive failures in these situations can prove disastrous (e.g., Loeb, 2002). Many high-demand situations depend heavily on an individual servicemember's ability to attend to the environment, hold mission-critical information in mind, and adjust and monitor thoughts and actions in the service of ongoing goals. While critical for mission success, such cognitive abilities may be at risk of being compromised under demanding circumstances, in which distractions, fatigue, and psychological stress can impair performance (Morgan et al., 2006; see also Jha et al., 2016). Accordingly, specialized military training aims to develop considerable procedural and declarative knowledge necessary for operational success, and inure individuals to constant-yet-unpredictable situational demands (NATO, 2012). Unfortunately, these intensive training and “stress inoculation” programs may themselves degrade and compromise cognitive functions such as attention and working memory (e.g., Morgan et al., 2006).

As such, there is a significant need for training methods that may successfully target cognitive functioning in servicemembers to best support their operational readiness and mission success. One avenue for improving cognitive functioning in servicemembers is computer-based cognitive training. One study recently explored the application of computerized cognitive training for reducing rates of noncombatant injuries in a simulated shooting environment (Biggs et al., 2015). Noncombatant or friendly fire injuries frequently occur when shooters misidentify their target or fail to appropriately inhibit pre-potent responses resulting in unintentional harm to noncombatants or allies with weapons fire. Such errors can have disastrous consequences, promote concerns regarding the harm of servicemembers from those within their own units, and increase the risk of psychiatric illness (e.g., post-traumatic stress disorder) for the survivors of these incidents (Pietrzak et al., 2011). Biggs et al. (2015) found that individuals with poor cognitive control, specifically inhibitory control, were more likely to injure civilians in the simulated scenario. These findings are consistent with other research findings demonstrating the negative consequences of failures in attentional and motor control on the frequency of simulated friendly fire incidents (e.g., Gamble et al., 2018; Wilson et al., 2015). Importantly, however, 3 h (over three consecutive days) of computer-based response-inhibition training was shown to reduce the frequency of simulated civilian casualties, providing initial support for the military application of computer-based cognitive trainings (Biggs et al., 2015). Such cognitive training may, therefore, have significant practical and life-saving benefits.

Recently there has been growing interest in the use of such training techniques for broad dissemination in military populations (Blacker et al., 2018). A central issue emerging from this literature is the degree of transfer from the trained context to novel and unrelated tasks (see Blacker et al., 2018; Simons et al., 2016). Far-transfer of training is exemplified when there is minimal or no featural overlap between the training task and tasks on which improved performance is observed. Given that there is a high degree of uncertainty, novelty, variability, and ambiguity in military operations, training which could achieve far-transfer in strengthening attention and working memory, for example, would be highly beneficial. Yet, most computer-based trainings have primarily observed near-transfer effects (Sala and Gobet, 2017), in which performance benefits are restricted to those contexts sharing features with the training program. Despite this, there is great practical utility for computer-based training approaches involving near-transfer of learned skills. For example, in military settings, receiving training to become proficient in the use of a specific piece of equipment could be quite beneficial and cost-effective. Nonetheless, identifying training methods that provide broad and generalizable benefits over many contexts remains of central interest in civilian and military settings.

Interestingly, there has been emerging evidence that mindfulness training (MT) may bolster a range of cognitive control-related functions such as attention and working memory, with studies finding that cognitive benefits transfer between the training context of mindfulness practice and the testing context of computer-based cognitive tasks (see Lutz et al., 2015). Thus, MT has been proposed to lead to generalizable improvements, akin to “far-transfer” effects in cognitive processes involved in directing attention and guiding thoughts and actions in line with internal goals (Slagter et al., 2011). For example, studies investigating MT have demonstrated improvements on measures of attention (e.g., Jha et al., 2007; Zanesco et al., 2013), reductions in mind wandering (i.e., disruptive task-unrelated thought, Mrazek et al., 2013; Zanesco et al., 2016), and improvements in working memory (e.g., Chambers et al., 2008; Mrazek et al., 2013; van Vugt and Jha, 2011). Such benefits are of particular interest for high-performing military servicemembers who are confronted with a variety of demanding tasks on a daily basis (see Blacker et al., 2018; Deuster and Schoomaker, 2015).

Mindfulness training involves didactic content and systematized instruction for mental exercises designed to build attentional skills and cognitive strategies for maintaining attention on present-moment experiences. Mindfulness is defined as a mental mode characterized by attention to present-moment experience without conceptual elaboration or emotional reactivity (see Jha et al., 2010; Kabat-Zinn, 2013). Over time with continued and regular engagement in MT practice exercises, such training is thought to reshape habitual thought and action patterns and facilitate neural and cognitive plasticity among cognitive control processes (Lutz et al., 2015; Slagter et al., 2011). Some of the attentional benefits of MT, for instance, may be maintained for years in regular dedicated practitioners (Zanesco et al., 2018).

In the military context, MT has primarily been explored as a means of cognitive remediation, promoting resilience against declines in attention and working memory performance that may occur over highly demanding and stressful intervals (see Deuster and Schoomaker, 2015; Stanley and Jha, 2009). Prior research has shown that these cognitive functions are susceptible to stress-related degradation, and deficits have been observed over demanding periods such as special operations survival school training (Morgan et al., 2006), and intense combat training in conventional forces (Lieberman et al., 2005). MT has been shown to protect against declining cognitive capacity over protracted high-demand intervals such as pre-deployment training in conventional forces (Jha et al., 2010, Jha et al., 2015, Jha et al., 2016, Jha et al., 2017).

Two recent studies examined the protective benefits of short-form MT on Soldiers' sustained attention and working memory over a high-demand pre-deployment training interval (Jha et al., 2015, Jha et al., 2017). Soldiers were assigned to receive an 8-h, 8-week experiential-focused vs. didactic-focused MT program or undergo no training at all. While Soldiers who did not receive training showed decreased cognitive performance over time, Soldiers who received MT, particularly the experiential-focused group that emphasized in-class training and practice, showed less degradation. Moreover, compared to the didactic-focused group, the experiential-focused group demonstrated greater protection from cognitive decline in sustained attention (Jha et al., 2015) and working memory (Jha et al., 2017). Although these studies have provided evidence of “sustainment” (see Deuster and Schoomaker, 2015), such that MT might protect cognitive functions from decline over high-demand intervals, the potential for MT to improve cognitive functioning over baseline has not yet been established in short-form programs made available to military servicemembers. Furthermore, alternative, yet effective, program structures that might better accommodate servicemember's schedules with the time-pressure nature of military service, require further investigation.

The present study examined whether an 8-h Mindfulness-Based Attention Training (MBAT) program might improve attentional control and working memory in a cohort of SOF personnel. Participants were assessed on a number of cognitive performance and self-report measures at study onset (T1) and roughly 8 weeks later (T2). In line with prior studies of MT in military cohorts, sustained attention and response inhibition were indexed with the Sustained Attention to Response Task (SART; Robertson et al., 1997), a go/no-go task that includes interspersed self-reported questions designed to catch moments of off-task thinking (i.e., mind wandering; Christoff et al., 2009). Working memory performance was assessed using a delayed-recognition task with affective distracters (WMDA; Jha et al., 2017), in which participants were instructed to remember target stimuli over a delay period during which negative combat-related images or neutral distracting images are presented. Furthermore, cognitive functioning in participants' daily lives was assessed by measuring the frequency of self-reported cognitive failures using the Cognitive Failures Questionnaire (CFQ; Broadbent et al., 1982).

To determine flexibility in delivery schedule of the 8-h program, SOF servicemembers were recruited from an active U.S. military installation and assigned to receive either a 2-week or 4-week version of MBAT delivered by an experienced mindfulness trainer, or they served as no-training control (NTC) participants and did not participate in any mindfulness training. We compared these groups on measures of attention, working memory, and cognitive failures in daily life before (T1) and after an 8-week interval (T2). To reduce bias in our analyses resulting from prognostic differences between non-compliant participants and program completers, we utilized multi-level linear mixed models in order to include all individuals in our analyses regardless of drop-out or MT program compliance (i.e., intention-to-treat analyses; Armijo-Olivo et al., 2009). As program assignment may contribute to motivational differences between groups, we further compared participants' performance motivation to engage in the post-training assessment in order to evaluate whether motivational differences confounded any potential performance differences between groups.

The present study aimed to address three main issues. First, we examined whether the 2-week MT, 4-week MT, or NTC groups changed on cognitive outcomes from T1 to T2. Second, we assessed whether MT groups differed in amount of out-of-class practice time, and whether practice time was correlated with cognitive improvements across individuals over time. Third, we explored whether motivational differences might have contributed to these outcomes. Given that SOF personnel have been selected for service based on their exemplary physical and cognitive abilities, we predicted that unlike studies in conventional forces, SOF personnel may not demonstrate degradations in their attention and working memory over the study period. Improvements in measures of cognitive functioning, observed with 2- or 4-week delivery of MBAT to SOF cohorts in this initial study, may motivate further investigation of the utility of MT as a route by which to enhance attention and working memory for high-demand settings and professions.

Section snippets

Participants

One hundred and twenty healthy active-duty male participants were recruited from 2 SOF units at a U.S. Military installation. Participants included both operational and support personnel, but all participants had completed a rigorous selection process and had undergone advanced military training in order to serve in their current unit. They had considerable military service experience (M = 10.89 years in service, SD = 5.01) and many had prior combat exposure. Personnel were assigned by unit to

Results

Demographic information was compared between groups at T1 using a series of univariate ANOVA. At the study onset, groups did not differ in educational achievement, F(2, 116) = 0.42, P = 0.659, years of prior military experience, F(2, 117) = 2.39, P = 0.096, or their amount of prior combat exposure, F(2, 117) = 1.85, P = 0.162, and groups did not significantly differ on measures of psychological health as assessed by GAD, F(2, 116) = 1.00, P = 0.372, PCL-M, F(2, 116) = 2.94, P = 0.057, PHQ, F(2, 116) = 0.59, P = 0.558,

Discussion

The broad aim of the current study was to investigate whether MT might improve cognitive performance on measures of sustained attention and working memory, and reduce cognitive failures in daily life, in a sample of high-performing SOF personnel. Military servicemembers were assigned to either a 2-week or 4-week version of a short-form (8 h) MT program called MBAT, or they received no training at all. Servicemembers who underwent the 4-week version of MBAT demonstrated significant improvements

Acknowledgments

The opinions or assertions contained herein are the private views of the authors and do not reflect the official policy or position of the Department of Defense, United States Public Health Service Commissioned Corp, or U.S. Government. We thank Keith Chichester, Emily Schwartz, Joanna Witkin, and Lindsey Slavin for their assistance with data collection, and MBAT advisory board members Maj. Gen. Walter Piatt, Col. (R) Michael Brumage, Col. (R) Charles Hogue, Sharon Salzberg, Dr. Jon Kabat-Zinn,

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