The Relationship Between Emotion Regulation and Executive Functioning After Sleep Restriction in Healthy Preschool Children

Executive functions are a set of higher level cognitive processes that are necessary for the selfregulation of behavior and emotion, which allow individuals to engage in planned, goal-oriented behavior, and guide attention. Emotion Regulation (ER) is the ability to control emotional arousal and adapt to the demands of the daily environment. Sleep has been demonstrated to be important for daily functioning in children, adolescents and adults. However, the impact of emotion regulation on the relationship between sleep and executive functioning (EF) in healthy preschool children has not yet been tested. This study investigated the relationship between ER, EF, and negative emotions after sleep restriction in healthy preschool children. It was hypothesized that ER scores would predict EF scores and negative emotions, and that this relationship would be moderated by the amount of sleep restriction experienced by the participant. Participants were typically developing boys and girls between the ages of 3-5 years (N=55), without sleeping difficulties. A significant relationship between ER and Delay of Gratification was found. No other significant effects were found. Results are discussed in relation to previous literature and specific characteristics of the sample. ER, EF, Negative Emotions, Sleep 3 The Relationship Between Emotion Regulation, Executive Functioning and Negative Emotions after Sleep Restriction in Healthy Preschool Children It is important for children to acquire adequate sleep each night in order to deal with the various demands of daily life. Mild sleep loss is common among young children (Molfese et al., 2013). Consequently, it is integral that children adjust to changes in sleep in the most adaptive way in order to avoid temper tantrums and oppositional behavior. Emotion regulation (ER) and executive functions are skills that are used every day in a variety of situations. Executive functions are cognitive abilities that allow individuals to allocate attention towards tasks for engaging in purposeful behavior (Bernier et al., 2010). The ability to regulate emotions is important for the development of social relationships and dealing with life challenges. Negative emotions can have a powerful adverse impact on behavior, thus adequate regulation of these emotions is necessary for optimal functioning. The present study addresses the relationship between ER, EF, and negative emotions, moderated by sleep restriction during early childhood. Emotion Regulation (ER) and Executive Functioning (EF) both improve over the course of development, beginning at ages 3 – 4 (Rothbart et al., 2013). ER has been defined as the ability to manage emotional arousal in order to achieve individual goals and adapt to the social environment (Thompson, 1994). Poor ER skills have been associated with both internalizing and externalizing problems in children (Calkins, 1994; Hill, Degnan, Calkins & Keane, 2006). For example, a child with poorly developed ER skills may start crying when he cannot find his lucky shirt before going to school. This may lead the child to throw his cereal on the floor, which may result in a temper tantrum. Instead of verbalizing his feelings of frustration and seeking his mother’s help, the child cannot regulate his emotions and may consequently act out his anger. ER, EF, Negative Emotions, Sleep 4 Executive Functions Executive functions are defined as a set of higher-level cognitive processes that are necessary for the self-regulation of behavior and emotion, which allow individuals to engage in planned, goal-oriented behavior and to guide attention (Bridgett, Oddi, Laake, Murdock & Bachmann, 2013). Executive functions, controlled by the prefrontal cortex, are important in situations marked by distraction, novelty, or stress (Turnbull, Reid & Morton, 2013). Shifting attention, working memory, inhibitory control (i.e., the ability to inhibit inappropriate or irrelevant information or behavior when performing tasks), and delay of gratification tasks are some of the many available measures of executive functions. These measures of executive functions overlap with the general construct of executive attention (Welch, 2001), defined as the ability to monitor and control behaviour, and engage in planning for actions (Rothbart & Reuda, 2005). Executive functions develop rapidly across the preschool years, continue developing into early adulthood (Turnbull et al., 2013), and are extremely important throughout childhood. Disruptions to EF development, caused by negligent or overly permissive parenting, may result in detrimental consequences for children in the domains of social control, cognitive functioning, behavior and emotional control (Anderson, 2002). With regards to behavior, executive dysfunction may be associated with poor impulse control and inappropriate social behavior. Children who display marked social difficulties as a result of weak ER may be vulnerable to increased negative emotions. Thus, executive functions are necessary for children to adapt to the demands of daily life. Executive Functions have been further divided into two sub-categories; one that is associated with hot (emotion laden) processing, and the other, which is associated with cold (emotionally independent) cognitive processing (Kim et al., 2013). Hot executive functions ER, EF, Negative Emotions, Sleep 5 include delay of gratification tasks, whereas cold executive functions include measures of inhibitory control, specifically the Go/No-Go task (Kim et al., 2013). Delay of gratification is considered to be a hot executive function because it involves regulating emotions, whereas an inhibitory control task is considered to be a cold EF task because it requires effortful attention and working memory (Kim et al., 2013; Bridgett et al., 2013). All children are faced with both emotional (hot) and cognitive (cold) challenges that require them to utilize EF skills in their daily life. For example, hot EF is required when a peer provokes a child, and the child is able to delay the gratification that comes from hitting the other child, by using self-instruction to walk away from the situation. Alternatively, cold EF is needed during a reading comprehension task where a student is required to sustain their attention and use working memory to answer the questions. Longitudinal research in preschool-aged children has established a positive relationship between ER and executive functions (Ursache, Blair, Stifter, Voegtline, 2013). Specifically, children who exhibited high emotional reactivity and demonstrated high levels of ER were also found to have high levels of EF ability (Ursache et al., 2013). Therefore, children require both strong ER and EF skills to deal with stressors and changes in their environment. Executive functions also overlap with the similar construct of effortful control (Bridgett et al., 2013), which has been defined as the ability to “inhibit a dominant response, to perform a subdominant, less salient response and to detect errors and engage in planning” (Rothbart & Bates, 2006). Effortful control is similar to executive functions because it involves the executive function of updating and monitoring information in working memory, and it utilizes focused attention. However, it is distinct from executive functions because it does not include inhibitory control (Bridgett et al., 2013). There is significant development of effortful control during the preschool years (Rothbart et al., 2011). It is important to understand effortful control because ER, EF, Negative Emotions, Sleep 6 studies have demonstrated that a relationship exists between high effortful control and low rates of negative emotions in young children (Rothbart et al., 2011). Negative Emotions Negative emotions are displays of negative affect (e.g., anger and sadness). In the preschool age range, children who experience increased levels of negative emotions may appear to be any of the following: somber, tearful, irritable, whiny, cranky, fear separation from their caregiver, and display withdrawn behavior. Insensitive caregiving has been associated with increased rates of negative emotions in young children (Bradley, 2003). Negative emotions in infants have been shown to be relatively stable across time (Ursache et al., 2013). Infants with a disposition to display high levels of negative emotions in reaction to novelty tend to consistently display negative emotions for the first five years of life (Kagan, Snidman, & Arcus, 1998), and this is related to reduced amounts of attention and inhibitory control (Rothbart, Ellis, Rueda, & Posner, 2003). Despite this continuity, changes have been reported with negative emotions during this time period (Ursache et al., 2013). Specifically, 13% of four month old infants labeled as highly reactive displayed an inhibited temperament at later assessments (Kagan, Snidman, & Arcus, 1998). This change in negative emotionality may be partially attributed to the development of ER behaviors (Ursache et al., 2013). During infancy, the automatic regulation of emotions, when coupled with arousal, is presumed to lead to the development of effortful control of attention, an integral component of executive functions (Ursache et al., 2013). Sleep in Young Children Sleep problems, defined here as difficulties initiating sleep and staying asleep, have been reported in 15% to 20% of toddlers and preschoolers within large normative samples (Jenkins et al., 1980; Richman, 1981; Scott & Richards, 1990). Specifically, between 10 and 30% of ER, EF, Negative Emotions, Sleep 7 children between 6 and 48 months of age exhibit sleep problems (Lozoff et al, 1996; Anders & Dahl, 2007). These sleep problems continue in 30% of children into adulthood (Anders & Dahl, 2007). Sleep is the main activity of the brain during the child’s early development (Dahl, 1996). The relationship between attention, sleep, arousal and emotions is an important area of invest