Aging is associated with alterations in macroscale brain topography and topology which may be related to cognitive decline (Iordan et al., 2018). Older adults show reduced modular brain organization, consistent with the theory of age-related functional de-differentiation (Betzel et al., 2014; Cao et al., 2014; Chan et al., 2014; Geerligs et al., 2015; Sala-Llonch et al., 2015; Baniqued et al., 2018; Iordan et al., 2018). Furthermore, aging is associated with a decline in higher-order cognitive abilities known as executive functions—these functions are critical to both simple and complex tasks of daily living, including managing medications and driving (Marshall et al., 2011; Park et al., 2014; Maldonado et al., 2020). Thus, there is a need to identify preventative interventions that might optimize brain organization and protect cognitive abilities into advanced age. This study examined whether an intervention paradigm based on theater acting would facilitate an increase in modularity and executive function in older adults.

Recent advances in gerontological research have shown that lifestyle factors can shape individual neural cognitive aging trajectories. The potential for modifiable lifestyle factors to reduce age-related cognitive decline has motivated the pursuit of lifestyle-informed interventions. Such interventions are situated within enriched environments, for example, exercise (e.g., Voss et al., 2013; Baniqued et al., 2018) and theater acting (e.g., Noice and Noice, 2013; Banducci et al., 2017). They are not targeted at enhancing any single cognitive skill. Rather, they are targeted to a diversity of inter-related skills, facilitating improvements in multiple cognitive domains (e.g., Wilson et al., 2002; Wang et al., 2013; Baniqued et al., 2018). These broad-based interventions stand in contrast to performance-adaptive computerized cognitive training that purportedly tap into specific aspects of executive functions, but do not show transfer to general cognitive function (e.g., Ball et al., 2002; Dahlin et al., 2008; Wilkinson and Yang, 2012; Karbach and Verhaeghen, 2014; Grönholm-Nyman et al., 2017).

Assimilating these perspectives, it is evident that broad-based interventions are more likely to demonstrate global gains in executive functions. Preliminary evidence also suggests that baseline brain modularity is predictive of improvements in cognitive performance ascribed to such interventions (Baniqued et al., 2018; Gallen and D’Esposito, 2019).

Acting is one such broad-based intervention strategy that embeds individuals in complex social contexts. A particular training model within acting is called “active experiencing.” Unlike exercise, active experiencing involves a conscious and combined recruitment of cognitive and related affective and physiological processes. Thus, it likely involves integration among multiple higher-order cognitive functions, particularly, aspects of executive function. Executive functions are cognitive operations that involve updating contents of working memory, cognitive flexibility, and inhibitory control (Miyake et al., 2000).

Working memory is engaged in active experiencing when actors repeat their performances several times in rehearsal without making an active effort to memorize the dialogues. These performances are continuously adjusted based on the “give-and-take” from other actors, while maintaining goal-relevant information in working memory. The repetition of performances ensures constant updating of working memory that is richly contextual and elaborate, including visuo-spatial awareness. By and large, this updating “style” allows the actor to gradually absorb the dialogue, leading to greater memory retention [(Noice and Noice, 2013); see also “deep processing” as mentioned in Craik and Lockhart (1972)]. Similarly, cognitive flexibility is fostered as actors adapt to different character roles, change and adopt new tactics that may seem more appropriate for obtaining a desired goal, and respond to feedback and “on-the-fly” changes in scripts or actors (Noice and Noice, 2013). Lastly, inhibitory control is exercised when the actor utters a script line. At this time, various parameters of the actor’s rendition that are representative of the script line must be reflexively encoded, including vocal inflections, posture, and affect. Concomitant to the actor’s goals of the present moment, they must actively suppress any non-verbal parameters that are not representative of the script line.

Preliminary results of active experiencing-based acting as an intervention strategy have been promising. For instance, a 4-week acting intervention in older adults produced improvements on a wide array of cognitive measures including word recall, working memory, problem-solving abilities, and participants’ perceived quality of life (Noice et al., 2004). These cognitive gains remained 4 months after training stopped. Using a similar intervention model but with a considerably larger sample of older adults, we showed control-adjusted gains in episodic recall that persisted up to 4 months post-intervention (Banducci et al., 2017). Remarkably, these findings illustrate that even relatively short-term interventions (i.e., 4-weeks) can facilitate enduring improvements in cognitive performance across multiple domains.

Although there is promising evidence of cognitive gains, the parallel changes in brain morphology associated with the acting intervention have not been examined. A particularly relevant brain measure in this regard is modularity (Newman and Girvan, 2004; Bullmore and Sporns, 2009; Rubinov and Sporns, 2010). Modularity evaluates the presence of modules, which consist of brain regions that are densely connected with each other but sparsely connected with others (Power et al., 2011). Greater modularity implies the presence of more distinct modules defined by greater coherency and greater segregation of functional networks. In this regard, modular organization may represent the basic “building blocks” of the brain that inform network development and function as well as support brain integrity. Furthermore, modularity has been shown to be particularly sensitive to context, such that subtle changes in cognitive functioning that might occur within very short time periods are well-represented at the level of modular organization (Stevens et al., 2012). Older adults tend to show reduced modular brain organization (Betzel et al., 2014; Cao et al., 2014; Chan et al., 2014; Geerligs et al., 2015). This observation falls in line with the de-differentiation hypothesis, which posits that separate cognitive abilities developed in childhood become more highly correlated with age, resulting in “de-differentiation” (Goh, 2011).

Apropos the cognitive training literature, modularity has been shown to be predictive of cognitive gains across diverse populations and intervention models (Baniqued et al., 2018; Gallen and D’Esposito, 2019). Emerging evidence suggests that modularity may parallel cognitive gains when the training emphasizes flexible learning of a higher-order cognitive function (Finc et al., 2020). The present research built upon these observations and examined brain-wide modularity benefits associated with acting training, in the same large-scale study as Banducci et al. (2017). Further, we sought to determine whether changes in brain modularity were associated with changes in executive function attributed to intervention effects.

To this end, we conducted a 4-week active experiencing-based acting intervention in older adults. Participants were administered a battery of cognitive tests and underwent MRI scans before they were assigned to either the active control (n = 86) or the acting-intervention condition (n = 93), depending on time of enrollment. The active controls attended an Understanding the Art of Acting (UAA) class, which was a course in theater appreciation. The acting-intervention group trained in Active Experiencing (AE). Specifically, participants in this group repeatedly performed short scenes with a partner while making effortful attempts to embody their character cognitively, affectively, and physiologically. Both groups were led by professional actors/ theater professors and met two times/week for 75-min for 4 weeks.

Within the randomized control framework employed in this study, we tested three hypotheses. First, we anticipated increased modularity in the intervention group and greater gains as compared to the control group, reflecting flexible higher-order learning and optimization of executive function (Finc et al., 2020). Second, we hypothesized that post-intervention scores on executive function tasks would clearly discriminate the acting group from the active control group, ascribed to the active experiencing training model. Tasks that were deemed discriminatory informed our final hypothesis. Specifically, our third hypothesis was that post-intervention performance on discriminant tasks would positively interact with changes in modularity to predict group membership to acting.

Consistent with our first hypothesis, our mixed-model analysis suggested a significant increase in modularity in the intervention group, relative to controls and the pre-intervention timepoint (β^ estimate: 0.04, p-value = 0.01 at the significance level α0.05; see Figure 1).

Descriptive statistics related to the tasks are presented in Table 2. The PLS-DA analysis showed that three tasks were found to carry group-separating information (Variable Importance in Projection >1). These discriminant tasks were Spatial Working Memory, 2-back, and Means-End Problem-Solving. Component loadings on these task measures suggest that post-intervention reaction time performance in these tasks were representative of the intervention group, not the control group. The amount of variance explained by this model was 19%. The error rate was 36%. Please see Table 3 and Figure 2 for the related results.

Based on the logistic regression analysis, we did not find any evidence of an interaction effect for modularity with any of the task performance scores. The related logistic regression results are presented in Table 4.

Prior research has suggested that theater acting can facilitate improvements in cognitive performance. We designed a 4-week theater-acting intervention in older adults to characterize the cognitive and brain changes associated with such an intervention.

Our mixed model analysis revealed greater increase in modular organization in the AE intervention as compared to an active control, suggesting a possible conferral of flexible learning and optimization of brain functions (Sporns and Betzel, 2016).

Using a PLS-DA framework, we found a significant post-intervention contribution of tasks that uniquely indexed the updating component of executive function. These tasks were Spatial Working Memory, 2-back, and Means-End Problem-Solving, and they were representative of the intervention group (Table 3). In older adults, updating has been identified as a key predictor of lab-based assessments of functional status—defined as the ability to perform tasks of everyday living—including the ability to manage finances and medication (McAlister and Schmitter-Edgecombe, 2016; McDougall et al., 2019). Furthermore, updating as well as episodic memory processes appear to specifically benefit from broad-based engagement interventions that are targeted at this population (Park et al., 2014; Banducci et al., 2017; Myhre et al., 2017). Within this context, it is worth noting that the Means-End Problem Solving task captures both updating as well as episodic memory processes (Vandermorris et al., 2013). Integrating these points, it appears plausible that when contributions of all executive functioning tasks are considered, performance gains ascribed to acting are related to the updating aspects of executive function and potentially, episodic memory.

Using a logistic regression approach, we did not find any significant interactions between modularity and task performance that could clearly discriminate the two groups. Thus, across all analyses, our results suggest parallel increases in modularity and updating, but not interacting relationships in these two variables that could sufficiently differentiate group membership. Of interest, the only study that has directly demonstrated changes in modularity corresponding with changes in cognitive training, used an adaptive version of the n-back task (Finc et al., 2020). However, this study did not determine how groups differed based on the interaction between modularity and adaptive n-back performance. Within the experimental group, the authors found that an increase of modularity observed during the 2-back condition of this task was not correlated with behavioral performance after training. They theorized that an increase in modular organization reflected a general consequence of training and may not interact with behavioral improvement. Our study provided evidence in support of this speculation. That said, we did not use the adaptive version of the n-back task, which may better index flexible learning, and therefore, modularity.

There is considerable evidence that brain modularity, as well as the updating component of executive function, and episodic memory, are particularly sensitive to and decline with the aging process (McAlister and Schmitter-Edgecombe, 2016; Sporns and Betzel, 2016; Banducci et al., 2017; Maldonado et al., 2020). Our results suggest that an active experiencing acting intervention can facilitate improvements in brain-wide organization and these aspects of higher-order cognitive functions.

We recognize that there are limitations to our study. From a neuroimaging standpoint, our instruction to participants to keep their eyes closed may have led to their sleepiness, which we did not explicitly follow-up on. Our instruction was guided by the observation that the resting state scan was sandwiched between two visually demanding scanner tasks (tasks not presented in this study). Notwithstanding, we note that all participants were alert and responsive to instructions that followed immediately after the scan and their performance on the task that followed did not indicate drowsiness.

From a behavioral methods standpoint, we found an error rate of 36% when classifying both groups using PLS-DA. This error rate may signal reduced sensitivity to executive function measures due to education effects (McAlister and Schmitter-Edgecombe, 2016), as our sample was highly educated. We also lacked a diversity of executive function tasks that uniquely mapped onto each subcomponent as well as other higher order functions. For instance, the Wisconsin Card Sorting Test measures the ability for flexible learning—a characteristic of executive function and modularity—but was not included in our battery of tests.

We acknowledge that the time of day when cognitive tests and MRI scans were conducted may have exerted an influence on the magnitude of performance on executive function tasks as well as whole-brain modularity measures (Schmidt et al., 2007; Farahani et al., 2022). We did not explicitly track participants’ habitual sleep-wake patterns to account for such individual-level presentations. Nonetheless, we surmise that the random assignment of participants into the two groups may control for time-of-day effects. Future studies should be explicit in their declaration of testing and scanning times.

We also note that while both groups were designed to be internally rewarding, we did not explicitly measure participants’ motivation, which can affect behavioral engagement. Thus, we cannot definitively say the extent to which our results are influenced by group differences in motivation.

Finally, the acting-theater researchers who supervised the two groups were also co-authors of this study (TN and HN) and the extent to which this factor may have influenced the research outcomes is difficult to determine.

We conducted a 4-week active experiencing-based acting intervention in older adults, within a randomized control trial framework. We anticipated enhancements in modularity and executive functioning, attributed to the intervention. We also investigated how changes in modularity were related to identified changes in executive function. These analyses were primarily conducted in a discriminant analysis framework. We found that the intervention group was characterized by higher post-intervention scores on tasks indexing the updating component of executive function. These tasks were termed “discriminant tasks.” None of the discriminant tasks significantly interacted with change in modularity to predict group assignment (i.e., intervention group or control group). We suggest that some attributes of modularity—such as flexible learning—were not effectively captured by our executive function measures. Nonetheless, our findings are promising since they suggest that an active experiencing based acting intervention can facilitate improvements in aspects of higher-order cognitive functions and brain-wide organization.

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://osf.io/pr4kt/?view_only=2caec53f73df48178fe0b53d1d19a003, identifier: DOI 10.17605/OSF.IO/PR4KT.

The studies involving human participants were reviewed and approved by the University of Illinois Institutional Review Board. The patients/participants provided their written informed consent to participate in this study.

TN, HN, and AK designed and directed the project. AR conceived of the presented idea and developed the conceptual framework. RB assisted in performing all analyses. AD aided in interpreting the results. PB and MV verified the analytical methods. All authors provided critical feedback and helped shape the research, analysis, and manuscript.