The prefrontal cortex plays a predominant role in executive functioning, spanning across the core elements: inhibition, working memory and cognitive flexibility, of which interact to form the fundamentals of reasoning of a higher level such as planning, problem-solving and goal-directed activity (Miyake, Friedman, Emerson, Witzki & Howerter, 2000). Executive functioning is shaped by early childhood and related skills such as self-regulation and social and emotional regulation are critical for learning in the classroom and social interactions and communication with peers and has shown to remain crucial throughout later life (Vaughan, Giovanello, 2010; Zelazo, Craik & Booth, 2004). For instance, a substantial amount of evidence currently exists which link improvement to executive functioning, more specifically, to working memory, with significant gains in mathematics in students (Blair & Razza, 2007; Bull & Scerif, 2001; Holmes, Gathercole & Dunnings, 2009; Mazzocco & Kover, 2007) and therefore, their success at school (Alloway & Alloway, 2010; Blair, 2002). The degree of the importance of the quality of executive functioning in children has been established and thus, several intervention techniques were introduced such as computerized training, classroom interventions and exercise, all of which, to some extent, demonstrate the improvement of components such as working memory and self-regulation. This essay will assess the extent to which each intervention technique is successful in doing so and will provide directions for future research.
Working memory is an important component of executive functioning and it has been established that the learning competency of children with low working memory capacity is hindered as a result of difficulties maintaining focus and poor ability to store information temporarily during cognitive activities (Gathercole & Alloway, 2008). Arguably one of the most successful techniques that currently exists to improve the executive functioning, in particular, the working memory of children is computerized training programs (Bergman-Nutley et al., 2011). These are based on the idea that repeated practice and exercising the executive functioning of children is key to improving skills in different areas later on in life.
Many studies employed CogMed; a predominant program in the field of study as a function of improving and boosting the poor working memory skills in children and were therefore, at a disadvantage with their learning (Bergman-Nutley, 2011; Klingberg et al., 2005; Thorell, Lindqvist, Bergman, Bohlin & Klingberg, 2009). One study in particular, produced fascinating results which lend support to the premise that interventions directed at boosting working memory lead to improved performance in children. Holmes et al. (2009) carried out either adaptive or non-adaptive versions of the training program on 42 children between the ages of 8 and 11 years. The non-adaptive program was developed by CogMed and had fixed difficulty levels throughout the tasks, so as to ensure that the working memory of the children were not too overworked. However, the adaptive version of the training program was carried out such that difficulty levels matched the memory span ability of the individual participants. Other than this, the adaptive and non-adaptive programs did not differ. IQ and academic performance were measured prior to, and after the training period during which participants were tested on their verbal short-term and working memory, visuo-spatial short term and working memory, in addition to verbal and performance IQ and literacy and mathematical reasoning.
Whilst no significant improvements were found for both the adaptive and non-adaptive groups immediately after the training, participants whom had undergone adaptive training appeared to have had benefitted the most during post-testing 6 months later. In particular, the adaptive group displayed significant gains in their verbal working memory and visuo-spatial short-term memory, however, not for verbal short-term memory. In addition, further analyses were conducted in order to uncover the improvements to working memory specifically by calculating the extent to which the participants achieved scores appropriate to their age. In doing so, it was found that 68% of the adaptive training group appeared to have achieved this, in comparison to 25% of the non-adaptive training group. Despite the marked differences in performance scores of the groups which had different types of training, it is evident that overall, the training of working memory does ultimately result in improvement to executive functioning. The study had its strengths with its regards to the consistency of training the children had received. The training period occurred over 5-7 weeks, 35 minutes a day for 20 days and was completed in small groups. The benefits of such training is that it actively stimulates activation in parts of the brain involved in working memory and thus, improvements can be accounted for by the training (Olesen, Westerberg & Klingberg, 2004; Westerberg & Klingberg, 2007). However, as aforementioned, verbal short-term memory was the only subcomponent of working memory which had not been affected by the training. In addition, the study involved 42 participants from the North-East of England, generalizability of results to the general population is placed into question. Therefore, future research could focus on verbal short-term memory as a distinct element which appears to be supported by the central executive component of working memory (Pickering, Gathercole & Peaker, 1998), as well as applying this intervention technique to more samples spanning other regions of England, including London, so as to gain results richer in reliability. Regardless, this study shows that computerized training as an intervention technique is, to an extent, successful in improving and refining working memory and appears thus far, to provide an efficient baseline for which future research can develop and improve on.
Existing research into the ability to modulate and control attention, behaviour and displays of emotion according to the social situation and environment, known as self-regulation, has been found to be a predictor of academic achievement (Blair & Razza, 2007; McClelland et al., 2007). The role of poverty on children’s self-regulation regarding emotional and behavioral development has then been revealed to correlate with performance and success at school (Aber, Jones & Cohen, 2000; Morales & Guerra, 2006;). Therefore, it is inevitable that prior to school entry, children from low income households are already at high risk of underachieving, in comparison to their high-income counterparts (Hoff, 2006).
The Chicago School Readiness Project (CSRP) is an intervention introduced to 35 classrooms which targeted the emotional and behavioral self-regulatory skills of low-income pupils, in order to tackle existing inequalities in school readiness and performance (Raver et al., 2011). It is recognized that disruptive and poorly modulated behaviour is linked to negative and reduced engagement of children in the classroom, which can in turn hinder their learning experience (Blair, 2002). The project consisted of delivering support and training to teachers with ways in which to effectively assist the control and regulation of children’s own behaviours and emotion in the classroom. For example, rewarding positive behaviour and enforcing rules. Mental health consultants and support workers were also involved in the project as additional support to teachers, as well as the running of workshops which focused on managing and reducing stress of teachers. The self-regulatory and pre-academic skills of 3-4 year olds were collected beforehand and following the completion of the project, it was found that the executive functioning of the children had greatly improved, as well as their attention skills and impulse control. As hypothesized, the academic performance of the children had improved as a result of the intervention, in comparison to that of the control group. Such performance was then predictive of the math and reading skills of the children three years later. The effectiveness of the intervention can be lent to the fact that no such training or support was provided to the teachers with regards to their teaching techniques, nor was there any to the children’s existing academic skills. The focus was purely on executive functioning and thus, the overall improvement to their skills uncovered the critical role of self-regulation with regards to emotion and behaviour, in determining and facilitating children’s academic performance and achievement.
However, limitations to the study can be identified for future research. Firstly, parenting has been determined as an important factor with regards to the development of emotional arousal and attention skills of children (Fisher, Stoolmiller, Gunnar & Burraston, 2007). For example, parenting dimensions such as maternal sensitivity and autonomy support were identified as relating to the development and progression of children’s executive functioning (Bernier, Carlson & Whipple, 2010). Therefore, such studies emphasize the importance of the quality of parent-child relationships and so, should be taken into consideration for future interventions which should include support to parents of low-income children, in addition to their teachers, so as to ensure most effective improvements and development of learning. Despite the limitations, it is clear that the success of the CSRP in identifying the link between self-regulation and school performance, although not entirely without its faults, also exists as an appropriate baseline for which future interventions targeting the executive functioning of children can be built upon.
As mentioned, the prefrontal cortex is heavily involved in the main aspects of executive functioning (Robbins, Weinberger, Taylor & Morris, 1996; Roberts, Robbins & Weiskrantz, 1998). It has been established that exercise improves prefrontal cortex function and therefore, in turn, an association has been made between exercise and the improvement of executive functioning. For example, Taras (2005) produced results which reveal that the participation in physical activities lead to the transfer of skills to classroom settings such as cooperation, sharing and learning. Thus, few pieces of research have focused upon exercise as an intervention technique for the improvement of executive functioning skills (Best, 2010).
Davis et al. (2011) tested this hypothesis in a 3-month long study whereby they assessed the cognition and academic achievement of 171 children aged between 7-11 years, whom were classed as overweight or inactive, before and after being randomized to either low doses or high doses of exercise; engaging in 20 minutes or 40 minutes of exercise per day, respectively. The children were tested using the Cognitive Assessment System which measured components of executive functioning such as self-regulation and intentionality, as well as consisting of scales such as the Planning scale which ensured that the exercise had an effect on executive function, as opposed to other cognitive processes and in doing so, it ensured reliability of measures. The Woodcock-Johnson Tests of Achievement III (McGrew & Woodcock, 2001) were used to measure academic achievement. It was observed that the participants benefitted significantly from the study, such that both the high and low dose groups presented high scores on the Planning scale, which indicated improvements to their executive functioning. Meanwhile, the control group did not yield results which suggested any such development; neither with executive functioning, nor academic performance. On the other hand, the exercise groups showed improvement to mathematics, however, none to reading. Such results support existing research linking improvements to executive functioning with increased skill in mathematics (Blair & Razza, 2007; Bull & Scerif, 2001; Holmes et al., 2009; Mazzocco & Kover, 2007) The study also involved an fMRI sub-study which, after analysis, produced results which also support previous findings that exercise leads to increased activity in the prefrontal cortex (Thomas & Stephane, 2008; Tomporowski, Davis, Miller & Naglieri, 2008; Tsujii, Komatsu & Sakatani, 2013). Demographics such as gender and race were also considered during randomization of the participants to groups and analysis of results revealed no such influence on the model. As a result of this, it can be postulated that this intervention technique is successful in improving the executive functioning of overweight Black and White 7-11 year olds.
However, as the study targeted only overweight or inactive Black and White 7-11 year olds, results cannot be generalized to other samples including children of different ages, ethnicities and levels of physical activity. In addition, it can be argued that due to the fact that the design consists of a control group which did not undergo any training, other factors that could have influenced results such as enjoyment of the trials and focused attention from adults and peers could not be ruled out. Also, results may not be completely accounted for by exercise alone, as studies show that the communication and interactions that occur between peers during exercise lead to psychological changes which in turn, could lead to improvements in academic performance (Ekkekakis & Backhouse, 2009; Norris, Carroll & Cochrane, 1992). These shortcomings therefore affect the validity of results and the extent to which exercise can be attributed to improvements to executive functioning. Such findings are similar to that of other existing research into the role of exercise as an intervention technique, as well as some which do not in fact lead to improvements in executive functioning (Kamijo et al., 2011; Manjunath, Telles & Indian, 2001). The disparities in the field of research relating exercise to executive functioning therefore require more extensive exploration, including a sample more representative of the wider population and taking other factors such as social interactions into consideration, as well as other types of exercise such as martial arts and yoga (Flook et al., 2010; Gothe, Pontifex, Hillman & McAuley, 2013).
There is no doubt as to the crucial role of executive functioning in the growth and development of children with regards to their emotional and social development, goal-directed behaviour and impulse control (Miyake et al., 2000). Such factors develop early on in life and have been found to constantly change and develop throughout a child’s life; influencing school performance and the quality of their social interactions with others (Vaughan & Giovanello, 2010; Zelazo, Craik & Booth, 2004). Therefore, interventions targeted at improving components of executive functions remains important in developmental psychology.
In summary, despite the fact that there does appear to be a sufficient amount of evidence pointing towards the improvement of executive functioning skills as a result of intervention techniques, it is clear that some methods are perhaps more effective than others. Firstly, regarding the development of the computerised training program targeted at working memory skills, which, although yielded results which lent support to the hypothesis that the improvement of working memory results in mathematical refinement (Blair & Razza, 2007; Bull & Scerif, 2001; Holmes et al., 2009; Mazzocco & Kover, 2007), it is clear that further research, such as those focusing on verbal short-term memory is required (Pickering et al., 1998), which may enhance the current understanding and knowledge of the role of working memory as a component of executive functioning in learning. Next, as existing research has emphasized the function of self-regulation in classroom learning (Blair & Razza, 2007; McClelland et al., 2007), despite the shortcomings of the study of Raver et al. (2011), delivering support to teachers with regards to the children’s emotional and social regulation is shown to be an effective process of improving school performance. Finally, physical exercise, as presented by fMRI analysis in addition to performance and executive functioning scores proved to lead to improvement (Davis et al., 2011), however the inconsistencies in the overall body of research relating to exercise as an intervention study places into doubt its validity.
To conclude, enhancements of executive functioning can be attributed to the intervention techniques undertaken, and existing research clearly provide an adequate baseline for a field of research which so clearly requires deeper, more comprehensive investigation.