Mindfulness Interventions and Executive Functions: Cognitive and Clinical Implications for Children and Adolescents

Introduction

The core concept of executive function has been much widened after its consideration in the influential working memory model, in terms of the central executive, the system of the multicomponent working memory that coordinates the work of the other components of it (Baddeley & Hitch, 1974). In particular, the tripartite model (Miyake et al., 2000) highlights three core executive functions (EFs): shifting between tasks, updating working memory contents and inhibition of prepotent responses.

It has to be noted that EFs are not limited to these three processes, and thus include impulse control, attention regulation and several others higher-order cognitive functions, which are modulated by prefrontal cortical brain areas and neurotransmitter systems, such as, dopamine, serotonin, and noradrenaline (Logue & Gould, 2014). These processes are top-down, i.e. refer to cognitive processing guided by knowledge, expectations, working memory, conscious access and attentional control. Bottom-up processing is instead driven by stimuli and their context, such as when attention is captured by an emotionally salient object. In the actual task performance these two aspects of cognitive processing are overlapping and interact for a better performance (Sarter et al., 2001).

An emergent property of EFs is cognitive flexibility, which is the capability to efficiently adapt to changing environmental situations, and a readiness to selectively switch between different mental processes. It is most often observed in the form of set shifting, that is changing from one set of rules to another, for example taking different aspects of stimuli into consideration, or in a more complex form of task switching, that is efficiently re-deploying cognitive resources to a different task. Cognitive flexibility, in order to be successfully implemented, requires several sub-domains of EFs: salience detection and attention, working memory, switching and inhibition (Dajani & Uddin, 2015).

Zelazo and Carlson (2012) further distinguished between “hot” and “cool” EFs. Cool EFs are implicated in classical cognitive tasks, such as the Wisconsin Card Sorting Test (Berg, 1948) and the Stroop task (Stroop, 1935), which do not involve a realistic reward and are usually associated with lateral prefrontal cortex activation. In contrast, “hot” EFs are employed in emotionally and motivationally involving high-stake situations, although implicating as well top-down processes associated with the activation of orbitofrontal cortex and other medial prefrontal regions. These two types of EFs develop unevenly: “cool” EFs develop progressively with age, reaching their peak at 14 years of age, while “hot” EFs develop following a bell-shaped curve, and start decreasing after the peak at age 14-15 (Poon, 2018).

It has to be noted that research on interventions based on the enhancement of EFs has mostly focused on cognitive efficiency and underestimates the importance of stress, mood and physical health (Diamond & Ling, 2016). In everyday life, however, one can note the extent to which stress, depressive mood and lack of sleep affect executive functioning by reducing self-control, clear thought and rational decision making. Thus, a mere training of certain task-focused executive functions might not be as effective as a more integrated intervention which also affects emotion regulation.

In this chapter we address the development of EFs, the age of their highest liability, their neural correlates and the types of the most used interventions enhancing EFs. In the following sections we highlight an intervention to enhance them, i.e. mindfulness training. Mindfulness is an enhanced attention to and awareness of the present experience with a non-judgmental attitude to whatever is happening at the given moment (Walsh & Shapiro, 2006), which can be cultivated through mindfulness meditation practice. Mindfulness training is an integrative approach aiding cognitive functions, self-regulation, as well as emotion regulation. A great body of evidence support its benefits for cognitive performance (e.g., Raffone & Srinivasan, 2010, 2017).