Ⅰ. Introduction
Sensory processing and executive functioning in children have been researched extensively as individual concepts, yet little literature exists examining the relationship between the two concepts. Both sensory process and executive constructs are critically important to children’s development and influence how they engage in daily occupations, particularly within the school environment (Adams et al., 2015; Critz et al., 2015; Fernández-Andrés et al., 2015). Accordingly, occupational therapists have a key role in addressing challenges in both sensory processing and executive functioning in order to enable and optimise the engagement and participation of children in their daily activities and life roles (Case-Smith, 2014; Cramm et al., 2013; Pfeiffer, Clark, & Arbesman, 2018).
This study examined the degree of association between sensory processing factors and executive functioning using the Sensory Processing Measure (SPM) and Behavior Rating Inventory of Executive Function, Second Edition (BRIEF2) (Gioia et al., 2015; Parham et al., 2007). By examining the correlations between scores of the SPM subscales and composite indices of the BRIEF2, this study investigated whether children’s sensory processing factors were predictive of the behavioural, emotional and cognitive regulation aspects of their executive functioning. In doing so, the findings could be used to inform evidenced-based practice in paediatric occupational therapy to improve sensory processing and executive functioning, and thereby improve occupational engagement, occupational performance and quality of life outcomes in children.
Ⅱ. Literature Review
1. Sensory processing
Sensory processing refers to a neurobehavioural process combining the reception and interpretation of stimuli from both the body and environment into an organised response (Dean et al., 2018; Fernández-Andrés et al., 2015). A child’s detection threshold and ability to regulate their response to stimulus such as touch, noise, vision, taste, smell or movement significantly influences their behaviour, social skills, cognitive functioning, and motor skills throughout their development (Brown et al., 2010; Little et al., 2016; Pfeiffer et al., 2018).
Dysfunction in sensory processing relates to differences in sensory thresholds and behavioural self-regulation (Reynolds et al., 2017; Simpson et al., 2019). Sensory thresholds refers to the level at which a stimulus triggers a response. For example, when a child has a low threshold they will detect and respond very easily, although these thresholds are variable and can thus fluctuate in different circumstances (Howe & Stagg, 2016). Difficulties in sensory modulation can manifest in two types of abnormal behavioural responses: over-responsivity such as an exaggerated negative response, or under-responsivity where the child exhibits decreased awareness of the stimuli (Adams et al., 2015; Critz et al., 2015). Atypical sensory processing is a common characteristic of conditions such as Autism Spectrum Disorder (ASD), Attention Deficit / Hyperactivity Disorder (ADHD), Developmental Coordination Disorder, tic disorders and other learning/developmental disabilities (Adams et al., 2015; Simpson et al., 2019; Soler et al., 2019).
Children with sensory processing issues will experience unique challenges when engaging in occupations typical to their age (Silverman & Tyszka, 2017). Difficulties may result in exaggerated negative behavioural responses, withdrawal or sensory-seeking behaviours, all of which interfere with the daily functioning of not only the child but also their peers and family (Dugas et al., 2018; Howe & Stagg, 2016). For example, children may be sensitive to different types of clothing materials, they may be fussy eaters that only consume a limited repertoire of food items, or easily get motion sickness when travelling by car, boat or air. Sensitivities can adversely influence the child’s attention, praxis patterns, social skills and willingness to participate, leading to feelings of isolation, low self-esteem, anxiety and increased challenging behaviours such as outbursts (Fernández-Andrés et al., 2014; Silverman et al., 2017; Soler et al., 2019).
Within the home, families must adapt their environment and activities to suit the sensitivities of the child (Howe & Stagg, 2016; Silverman & Tyszka, 2017). These adaptations are more difficult to achieve in a school environment where sensitivities to noises, bright lights, touch and smells in the classroom have been linked to reduced concentration, poor motor planning abilities, low academic performance, reduced engagement and increased antisocial behaviour (Fernández-Andrés et al., 2014; Howe & Stagg, 2016). Students may find it difficult to focus on verbal instructions or copy notes from a board if there are environmental noises or bright lights. Atypical sensory processing has been associated with impaired executive functioning, particularly working memory and inhibition (Adams et al., 2015). However, the relationship between the two has not been formally investigated to date. Often sensitives that present themselves in the home environment also present themselves in the school classroom context. As stated by Romero-Ayuso, Toledano-González, Segura-Fragoso, Triviño-Juárez, and Rodríguez- Martínez (2020) “A strong and positive relationship has been observed between difficulties in sensory processing and deficiencies in executive functions in children with neurodevelopmental disorders… difficulties in sensory processing and in executive functions usually come together” (p. 2).
2. Executive functioning in children
Executive functioning refers to a complex composite of cognitive processes involving higher order and goal-directed thinking, including working memory, inhibition, adaptation, attention shifting and planning (Adams et al., 2015; Pastor-Cerezuela et al., 2020; Pfeiffer et al., 2018; Rosenberg et al., 2017). It is associated with purposeful, adaptive activity and does not refer to level of intelligence (Cramm et al., 2013). Miyake et al. (2000) highlighted three key components of executive functioning: response inhibition, working memory and set shifting. Response inhibition refers to the ability to control impulses and focus attention, and overlaps with similar sensory processing concepts (Miyake et al., 2000; Rosenberg et al., 2017). Working memory is the ability to store information and dynamically integrate that information when needed (Miyake et al., 2000). Set shifting relates to a child’s ability to behave flexibly and adapt to changing environmental needs (Adams et al., 2015). All three concepts evolve and improve through childhood development and critically rely on the child’s ability to maintain attention (Rosenberg et al., 2017).
Executive functioning, and working memory in particular, has a considerable influence on a child’s literacy, academic achievement, skill development, occupational performance and independence (Cramm et al., 2013; St Clair-Thompson & Gathercole, 2006). The contribution of executive functioning to a child’s participation has been found to be greater than other factors such as motor ability (Rosenberg et al., 2017). Poor working memory is associated with a child making frequent errors in the classroom including difficulties in mental mathematics, following text, writing while formulating text, verbal fluency and carrying out instructions (Pastor-Cerezuela et al., 2020; St Clair-Thompson & Gathercole, 2006). Consequently, a child experiencing these difficulties is at high risk of becoming disengaged from classes and peers, engaging in disruptive behaviour or developing secondary health conditions such as anxiety and depression (Cramm et al., 2013). Impairments in executive functioning are common in children diagnosed with ASD, ADHD, anxiety disorders and learning disabilities (Pastor-Cerezuela et al., 2020).
No doubt children with executive functioning problems would also present with similar behavioral and working memory issues in the home environment. As noted by Romero-Ayuso et al. (2018), it is “Understood that a deficit of executive functions can have devastating effects on activities of daily life that could be interpreted as human occupations in a broad sense, such as school activities, self-care, play, leisure, and social participation” (p. 2). In other words, executive functioning facilitates goal-directed behaviour, cognitive development and learning, and emotional and behavioural regulation in school-age children which all underpin human occupation.
3. Occupational performance in children
The core focus of occupational therapy is to enhance participation in “occupations”, namely daily activities that hold a sense of meaning (Ashburner, 2014; Case-Smith, 2014). For children, these occupations are primarily self-care, schooling, social participation, sleep and play/leisure (Case-Smith, 2014; Cramm et al., 2013). Occupational engagement provides a valuable opportunity for a child’s learning and skill development as well as affording a sense of accomplishment, self-esteem and eventual independence (Rosenberg, 2018; Silverman & Tyszka, 2017). Importantly, schooling and play rely on social skills and engagement with others to facilitate participation.
However, learning at school, play, leisure and social participation can result in unique challenges for children with sensory processing and executive functioning issues (Rosenberg, 2018; Pastor-Cerezuela, 2020). Paediatric occupational therapists use a strengths-based, family-centred approach to goal setting and developing interventions that enhance a child’s engagement, routines, self-regulation and social interactions in daily life (Case-Smith, 2014). In collaboration with teachers and parents, therapists assess and promote a range of skills including cognition, behaviour, social skills, gross motor, fine motor, sensory processing and general development (Cramm et al., 2013). Occupational therapists also actively encourage school and community awareness of atypical sensory processing and executive functioning, and develop tailored environmental modifications in homes, classrooms and community settings (Reynolds et al., 2017; Silverman & Tyszka, 2017). Investigating the predictive relationship between sensory processing and executive functioning will inform service provision for paediatric occupational therapy to improve the efficacy of these interventions.
4. Purpose
The purpose of this study was to investigate the relationship between sensory processing and executive functioning in typically developing children. In support of this aim, the following research questions were posed:
1) Is there a significant correlation between sensory processing (as measured by the SPM) and the three BRIEF2 composite indices: i) behaviour regulation index; ii) emotional regulation index; and iii) cognitive regulation index?
2) Are sensory processing factors (as measured by the SPM) predictive of the executive functioning indices of the BRIEF2?
3) Are the sensory processing factors (as measured by the SPM) predictive of the global executive composite score of the BRIEF2?
Ⅲ. Methods
2. Participants
Participants in the study were parents/guardians of typically developing children between the ages of 6-10 years. Children ages 6-10 years were selected as the recruitment age-group since they attended school on a full-time basis plus this was a common age overlap between the standardised data collection scales. Recruitment was conducted at two local government schools in Victoria, Australia through the use of convenience sampling. School administration staff identified suitable classrooms within the two schools that children ages 6-10 years attended and approximately 240 initial information kits were distributed to potential participants.
The inclusion criteria included: the participant was a parent/guardian of a child between the ages 6-10 years; the child was attending a state-funded primary school in Victoria, Australia; the child had no known history of developmental delay or learning disability; and the parent/guardian had a working knowledge of written English language. Of the parents who responded to the information kits, a total of 44 parents (initial response rate of 18.3%) met this inclusion criteria and provided written informed consent prior to their engagement in the study. Two participants, however, later withdrew during data collection and a further two were lost to follow-up. A final sample of 40 was obtained from the two schools (overall response rate of 16.6%), which included 20 male children (50%) and 20 female (20%).
3. Instrumentation
1) Sensory Processing Measure - Home Form (SPM) (Parham and Ecker, 2007)
The SPM is a standardised 75-item caregiver questionnaire used to assess sensory processing by recording the frequency of sensory processing issues, social participation and praxis in children aged 5-12 years (Parham et al., 2007). Based on Ayres’ (2005) theory of sensory integration, the questionnaire covers eight constructs: social participation, vision, hearing, touch, body awareness, body and motion, planning and ideas, and total sensory systems. Responses are recorded using a 4-point Likert-type scale, with 1 = “never” and 4 = “always”. Higher scores indicate a higher level of dysfunction.
Standardisation of the SPM was conducted using a sample of 1,051 children in the United States (Parham et al., 2007). The manual authors reported high internal consistency (α = .77) and test-retest reliability (r = .94) (Parham et al., 2007). Content validity was achieved through the use of Ayres’ theory throughout development and expert peer-review. External studies have evidenced convergent validity between the SPM and the original Sensory Profile (Brown et al., 2010; Dugas et al., 2018). In their 2010 study, Brown et al. evidenced significant subscale correlations ranging between .36 (p < .05) and .74 p < .01).
The SPM Home Form (completed by a child’s parent or caregiver) was selected for this study instead of the SPM Main Classroom Form (which is typically completed by a child’s primary classroom teacher) since parents/caregivers often have more exposure to their children’s sensory processing issues and behaviours particularly during meal times, bed time routines, and in various community environments. As well, since data collection was completed at one primary school, it was not possible to ask classroom teachers to fill out more than one SPM Main Classroom Form due to respondent burden concerns.
2) Behavior Rating Inventory of Executive Function®, Second Edition (BRIEF2) (Gioia et al., 2015)
The BRIEF2 is one of the most widely used standardised assessments for executive functioning in children (Dodzik, 2017). Based on several reviews and critiques, it is highly recommended as a measure of children’s executive functioning (Gioia, Isquith, Guy, & Kenworthy, 2015; Hendrickson & McCrimmon, 2019). The scale is designed to be completed by parents and teachers of children aged 5-18 years, however a self-report is also available for children aged 11-18. The BRIEF2 contains 63 items across the key domains of executive functioning: inhibit, self-monitor, shift, emotional control, initiate, working memory, plan/organize, task/monitor and organization of material. Scoring measures the frequency of behaviours using a Likert-type scale, where N = “never”, S = “sometimes” and O = “often”. Scores are then combined to form three composite indexes (Behaviour Regulation Index [BRI], Emotional Regulation Index [ERI] and Cognitive Regulation Index [CRI]) and a global executive composite score.
Standardisation of the BRIEF2 Parent Form was conducted in the United States using data collected from 3,603 children (Dodzik, 2017; Hendrickson & McCrimmon, 2019). Internal consistency (α = .76 to .97) and test-retest reliability (α = .79) in the parent form were found to be acceptable in the initial study (Dodzik, 2017; Soler et al., 2019). However inter-rater reliability scores were weak to moderate, suggesting inherent differences between raters (Hendrickson & McCrimmon, 2019). Concurrent validity was evidenced by moderate to strong correlations between the BRIEF2 and established measures of executive function (Dodzik, 2017; Hendrickson & McCrimmon, 2019; Shum et al., 2020).
4. Procedure
Ethics approval for this study was obtained from the Monash University Human Research Ethics Committee (approval number 10881) and the Victorian Department of Education and Training in 2019. Initial information kits included a screening questionnaire to determine the eligibility of potential participants and their children. Once written informed consent to participate had been obtained from eligible parents/guardians, paper-based versions of the SPM and BRIEF2 were distributed by teaching staff, completed by participants at home and then returned to the school in a sealed envelope. One parent was asked to complete both the SPM and BRIEF2. Responses were immediately de-identified and scored by one researcher to maintain internal consistency. Scoring was completed according to the SPM and BRIEF2 manuals and without reference to the participant information.
5. Data analysis
Collected data was stored and analysed using the Statistical Package for the Social Sciences© (SPSS) version 24.0. However, due to the small sample size bootstrapping was applied to allow for the more accurate interpretation of data. Descriptive statistics such as mean, standard deviation, range and interquartile range were calculated to interpret demographic information and overall scores. Correlational statistics were calculated using ordinal level data and Spearman’s rho correlations to identify any statistically significant associations between sensory processing and executive functioning variables. High correlations were indicated by coefficient scores above 0.70, moderate correlations were coefficients between .40 and .69, and low correlations were below 0.39 (Schober et al., 2018). A level of significance was set at p < .05. In investigating the relationship between sensory processing and executive functioning, multilinear regression models were used to calculate whether sensory processing factors as independent variables were predictive of the executive functioning indices.
Ⅳ. Results
1. Participant demographics and scale scores
The mean age of the 40 child participants included in the study was 7.42 years (89.05 months; SD = 11.13). The largest percentage of students were in Grade 1 (42.5%), while the overall sample ranged between Grade 1 and Grade 4. Child participants were commonly the first-born child in their family (60%), were likely to have one sibling (42.5%) and spoke only English at home (95%) (see Table 1).
Table 2 summarizes the mean scores for both the SPM and BRIEF2. The mean scores for the SPM subscales ranged between 9.9 (SD = 2.63) and 14.3 (SD = 3.12), with the total mean score of 66.45 (SD = 11.26). Based on the range of raw scores presented, it is possible that, despite the child participants being typically developing based on a parent report screening form, some of them may have presented with atypical sensory processing issues on one or more of the SPM subscales. The composite index scores of the BRIEF2 ranged between 17.48 (SD = 4.44) and 48.80 (SD = 13.55), while the Global Executive Composite mean score was 90.18 (SD = 21.93). There was no cut-off score used for the BRIEF2 in the study. None of the child participants were found to have any difficulties related to the three BRIEF2 composite index scores.
2. Correlations between sensory processing and the behaviour, emotion and cognitive regulation aspects of executive functioning
Correlations between the SPM subscales and BRIEF2 indexes are summarized in Table 3. These Spearman rho scores evidenced that nearly every subscale of the SPM was significantly correlated with one or more of the BRIEF2 indices after applying bootstrapping to the analysis. The only SPM subscale that was not significantly correlated with the BRIEF2 was the SPM Social Participation subscale. Conversely, the SPM Body Awareness and Planning & Ideas subscales reported the highest significant correlations across all the BRIEF2 indexes.
Table 3
Bootstrap Results for Spearman’s rho Correlations (2-tailed) Between the SPM Subscale Scores and BRIEF2 Indices Scores (N = 40)
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The BRIEF2 Emotion Regulation Index evidenced statistically significant correlations with all but two of the SPM subscales. The highest correlation scores overall both involved this index and were between the SPM Body Awareness-BRIEF2 Emotion Regulation Index (rs = .59, p < .05) and SPM Total-BRIEF2 Emotion Regulation Index (rs = .50, p < .05). The lowest correlations were between SPM Hearing-BRIEF2 Behavior Regulation Index (rs = .05) and SPM Touch-BRIEF2 Behavior Regulation Index (rs = .07).
1) Regression analysis between the SPM subscales and BRIEF2 executive functioning indices
Regression analysis was carried out for all significant correlations between the SPM subscales and each of the three BRIEF2 composite indices. The results of this analysis are summarised in Table 4. A predictive relationship was found between the BRIEF2 Cognitive Regulation Index (CRI) and the SPM Vision, Body Awareness, Balance & Motion and Planning & Ideas subscales (Adjusted R² = .34, F (4,35) = 6.02, p = .001). The SPM Planning & Ideas made a unique contribution to the model’s variance at 16.6% (p = .01).
Table 4
Regression Models for SPM Subscales & BRIEF2 Composite Scales Prior to Bootstrapping (N = 40)
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Regression results between the BRIEF2 Emotion Regulation Index (ERI) and the SPM Hearing, Touch, Body Awareness and Planning & Ideas subscales were significant (Adjusted R2 = .27, F (4, 35) = 4.69, p = .004). However following bootstrapping, only the SPM Planning & Ideas subscale made a statistically significant contribution to the model’s overall variance (12.4%, p = .05).
Regression analysis on the only significant correlation involving the BRIEF2 Behavior Regulation Index (BRI) revealed no significant regression or predictive relationship with the SPM Body Awareness subscale (Adjusted R² = .05, F (1, 38), p < .08). These results indicated that none of the SPM subscales were predictive of the BRIEF2 Behavior index.
2) Regression analysis between the SPM subscales and BRIEF2 global executive functioning composite scale
Table 4 also includes the regression analysis results for significant correlations between the SPM subscales and BRIEF2 Global Executive Composite (GEC) Index. The GEC score was shown to be statistically significant using the SPM Body Awareness, Balance & Motion and Planning & Ideas subscales (Adjusted R² = .37, F (3,36) = 8.60, p = .001). Again, the SPM Planning & Ideas subscale accounted for the highest unique contribution to the model’s variance with 17.7% (p = .01).
Ⅴ. Discussion
This study aimed to understand the association between sensory processing and executive functioning in typically developing children by measuring correlations in the scores of the SPM subscales and BRIEF2 indices. In doing so, it also aimed to investigate whether sensory processing scores were predictive of executive functioning factors such as behaviour, emotional, cognitive and global regulation. Results suggested that sensory processing may be predictive of emotional, cognitive and global regulation, but not behavioural aspects of executive functioning.
1. Correlations between sensory processing subscales and executive functioning indices
The SPM Planning & Ideas subscale demonstrated the strongest relationship with executive functioning, evidencing statistically significant correlations across all four of the BRIEF2 indices. This association is expected given the shared concept of planning in both sensory processing and executive functioning, and the mutual influence of both domains on each other (Adams et al., 2015; Pastor-Cerezuela et al., 2020). Fernández-Andrés et al. (2015) highlight that the behaviours incorporated in the SPM Planning & Ideas subscale are often more automatic when performed within the home as they are developed as part of a daily routine in a familiar, comfortable environment.
The strongest single correlation was between the SPM Body Awareness subscale and the BRIEF2 Emotional Regulation Index (ERI) (rs = .59, p < .05). This finding corresponds with existing understandings that a child’s physical coordination or appropriate exertion of force is in-part reflective of their capacity for attention (Critz et al., 2015; Koenig et al., 2010; Rosenberg et al., 2017), but also highlights the importance of emotional modulation and flexibility in this process. Additionally, the ERI evidenced the most statistically significant correlations across the SPM subscales, ranging between rs = .20 and rs = .59 (p < .05).
Of the three BRIEF2 indices, the Behaviour Regulation Index (BRI) exhibited the lowest correlations across the majority of SPM subscales. Correlations ranged between rs = .05 and rs = .38 (p < .05), with SPM Body Awareness and SPM Planning & Ideas evidencing the strongest levels of association with the BRIEF2 BRI. Despite behavioural self-regulation being a shared concept of both sensory processing and executive functioning (Critz et al., 2015; Miyake et al., 2000), the variability of behavioural responses by those with known sensory processing dysfunctions may partially explain the low levels of association between SPM subscales and the BRIEF2 BRI.
2. Regression analysis between the SPM subscales and BRIEF2 Cognitive Regulation Index
The results of this study indicated a strong predictive relationship between specific sensory processing factors and cognitive regulation as measured by the BRIEF2 Cognitive Regulation Index (CRI). The BRIEF2 CRI refers to active problem solving and incorporates factors such as planning and organising, task completion and working memory. The regression analysis was performed including all statistically significant correlation results between the BRIEF2 CRI and SPM subscales, namely: SPM Vision (rs = .36, p < .05), SPM Body Awareness (rs = .35, p < .05), SPM Balance & Motion (rs = .32, p < .05) and SPM Planning & Ideas (rs = .45, p < .01). The regression model accounted for 34% of the variance of the BRIEF2 CRI dependent variable, and was the strongest of the regression analyses using the three BRIEF2 indices (excluding the global composite score) (Adjusted R²= .34, F (4,35) = 6.02, p = .001), highlighting the strength of the specific relationship between sensory processing and cognition.
Existing literature highlights auditory processing as one of the most influential sensory modalities on cognition, balance, and vision (Ismael et al., 2018; Pastor-Cerezuela et al., 2020; Rosenberg et al., 2017). However, the importance of visual processing in cognitive regulation that was identified in this study was also identified by Adams et al. (2015) who found a strong relationship existed between visual attention and working memory. Visual perception can also influence fine motor skills and planning, and environmental interventions that decrease visual stimuli have proven effective in reducing arousal and improving attention and engagement in children with visual sensitivities (Case-Smith, 2014; Critz et al., 2015).
The recognised importance of attention on a child’s coordination, body awareness and use of force supports the contribution of the SPM Body Awareness and SPM Balance & Motion subscales in predicting cognitive regulation (Critz et al., 2015; Koenig et al., 2010; Rosenberg et al., 2017). The unique contribution of the SPM Planning & Ideas subscale to this predictive relationship (16.6%, p < .01) builds on the results of the correlational analysis and reflects the shared concepts of both scales. The SPM Planning & Ideas subscale incorporates sequencing, coordination, adaptation and problem solving, all of which are goal-directed behaviours influenced by executive functions, particularly working memory (Rosenberg et al., 2017).
Collectively, these findings support the ability of these four SPM subscales to predict cognitive regulation skills, such as kinesthetic abilities, praxis, proprioception, visual-motor integration skills, eye-hand coordination, and working memory. Children presenting with problems related to vision, body awareness, balance, dynamic movement, motor planning and motor ideation would no doubt present with cognitive and learning challenges (Pastor-Cerezuela et al., 2020). These might include dyslexia, dysgraphia, non-verbal learning difficulties, and processing disorders. Therefore, it is not surprising of the predictive relationship between the SPM sensory processing factors and the BRIEF2 CRI.
3. Regression analysis between the SPM subscales and BRIEF2 Emotion Regulation Index
The regression analysis of the BRIEF2 ERI and SPM subscales revealed a significant predicative relationship. The regression model incorporated all statistically significant correlations: ERI-SPM Hearing (rs = .41, p < .01), ERI-SPM Touch (rs = .40, p < .05), ERI-SPM Body Awareness (rs = .59, p < .01) and ERI-SPM Planning & Ideas (rs = .43, p < .01) which together accounted for 27% of the variance of the ERI dependent variable (Adjusted R² = .27, F (4,35) = 4.69, p = .004).
The BRIEF2 ERI encompasses the concepts of “shift” and “emotional control”, focussing on emotional regulation and flexibility as precursors to cognitive regulation (Dodzik et al., 2017). Body awareness concepts such as appropriate use of force and physical exertion are indicative of autonomous emotional and behavioural responses to stimulus (Gomez et al., 2017). Existing literature emphasises a child’s ability to modulate sensory input (particularly auditory and tactile stimulus) as being vital for not only maintaining attention, but also emotional self-regulation and adaptability (Ashburner et al., 2014; Fernández-Andrés et al., 2015; Howe & Stagg, 2016). Further, Koenig et al. (2010) identified the use of coping strategies that manage incoming stimuli as being a protective influence on a child’s adaptive ability and occupational performance in functional tasks. This concept lends to both emotional regulation and behavioural regulation, as evidenced by moderate correlations between BRI-SPM Body Awareness (rs = .38, p < .05) (Pfeiffer et al., 2018).
4. Regression analysis between the SPM subscales and BRIEF2 Behavior Regulation Index
No predictive relationship between the SPM subscales and BRIEF2 BRI was found in this study. A regression model was calculated using the one statistically significant correlation identified in the collected data, namely the BRI-SPM Body Awareness (rs = .38, p < .05), however no significant predictive contribution was identified (Adjusted R² = .05, F (1, 38), p < .08).
Typically, problematic behaviours exhibited by children presenting with sensory processing problems include hyperactivity, appearing clumsy, having a low pain threshold, being picky in relation to food preferences, finding noisy, busy environments overwhelming, and disliking certain getting hands dirty (Dean et al., 2018). Likewise, associated with sensory processing dysfunction are classified into two groups: internalising (anxiety or depression) or externalising (Gourley et al., 2013). The BRIEF2 BRI refers specifically to inhibition and self-monitoring, both of which are known to be negatively influenced by sensory processing dysfunctions (Fernández-Andrés et al., 2015; Gourley et al., 2013; Pastor-Cerzuela et al., 2020). However, studies have also evidenced sensory seeking behaviours and enhanced sensory perception as having a positive or mixed association with behaviour and occupational participation, namely in an effort to control incoming stimuli (Koenig et al., 2010; Little et al., 2017). A study by Dean et al. (2018) similarly found no predictive relationship between sensory processing patterns and internalising behaviours. Given the variability of behavioural responses by those with known sensory processing dysfunctions, this may partially explain the absence of any predictive relationship between SPM subscales and the BRI.
5. Regression analysis between the SPM subscales and BRIEF2 Global Executive Composite Index
The strongest predictive relationship identified in this study was between three SPM subscales and the BRIEF2 Global Executive Composite Index (GEC) (Adjusted R²= .37, F (3,36) = 8.60, p = .001). The regression analysis incorporated all significant correlation results between the BRIEF2 GEC and SPM subscales, namely the SPM Body Awareness (rs = .47, p < .01), SPM Balance & Motion (rs = .36, p < .05) and SPM Planning & Ideas (rs = .45, p < .01), together accounting for 37% of the variance of the GEC dependent variable. Again, the SPM Planning & Ideas subscale evidenced the strongest contribution to the regression model (17.7%, p = .00), reflecting the shared factors between sensory processing and executive functioning.
Given the GEC is a cumulative summary of the three BRIEF2 indices, it is expected that the evidence supporting the contribution of the SPM Body Awareness, SPM Balance & Motion and SPM Planning & Ideas subscales in predicting executive functioning would similarly apply in the composite index. Soler et al. (2019) also found significant associations between BRIEF2 GEC scores and increasing comorbidities in children with tic disorders and sensory dysregulation. However, the BRIEF2 authors acknowledge that while the GEC can be used as a summary measure, there are limitations in how adequately it reflects a child’s overall profile (Gioia et al., 2015). Therefore any clinical analysis of sensory processing dysfunction and executive functioning would be strengthened by using all of the BRIEF2 indices.
6. Limitations
Results of this study should be interpreted in context with its limitations. The study was limited by its use of convenience sampling and in relying on parents/guardians volunteering to participate, leading to potential recruitment bias. It was also limited by the small response rate and sample size. While employing bootstrapping to overcome this, the generalisability of results is still limited. In drawing its sample from only two schools in a local area of Victoria, Australia, the study was restricted by its geographical specificity. It also relied on two parent scales that were developed and standardised in the United States, raising questions of potential social desirability in responses and cross-cultural validity. However, both scales have been used extensively in Australian contexts since their publication. Data obtained through the two scales could also have been strengthened with collaboration from teaching staff.
7. Future research
Future research into the predictive relationship between sensory processing and executive functioning is required and should aim to include a larger sample with a wider age range. Investigating both concepts within the classroom environment using teacher reports is recommended. It is also recommended that future research consider assessing parent’s accuracy in reporting their child’s skills and preferences or include objective measurements alongside parent report tools to facilitate triangulation. This topic would also benefit from further research into condition-specific populations.
Ⅵ. Conclusion
Much of the existing theory regarding sensory processing speaks to higher order cognitive processes, such as executive functioning skills. Despite this, current evidence examining a connection between the two is limited. This study provides preliminary indications that inferences of a child’s executive functioning can be made from their scores in a sensory processing measure such as the SPM. From this, paediatric occupational therapists can provide appropriate, evidence-based services including assessment, goal-setting, intervention planning and effectiveness evaluation.