Some reflexes help babies move and respond to the world and usually fade as the brain matures. This study looks at whether these reflexes are more active in young children with developmental language disorder, helping researchers better understand how language and brain development are connected. Enjoy!

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Abstract

Purpose

Developmental language disorder (DLD) is a developmental disorder where children fail to acquire language in the absence of a clear cause. Many studies have reported general motor deficits in children with DLD, but no studies have uncovered a cure. The purpose of our study is to better understand the underlying motor deficits in DLD, starting from uninhibited primary reflexes—which are the most basic stage of motor development. Knowledge of this motor–language relationship should lead to earlier and more targeted interventions in young children with DLD.

Method

Children with DLD (n = 75, age range: 4–10 years) and 99 age-matched typically developing (TD) children completed a nonword repetition test to assess DLD and six other tests to assess primitive reflexes.

Results

Children with DLD demonstrated higher levels of persistent primitive reflexes compared to TD children. As the scores for neuromotor immaturity increased, nonword repetition test scores decreased (r = −.44, p < .01). Results indicated that TD children exhibited lower neuromotor immaturity (M = 7.63, SD = 3.75) compared to children with DLD (M = 13.51, SD = 4.47). All primitive reflexes (the Moro reflex, the symmetrical tonic neck reflex in flexion and in extension, the asymmetrical tonic neck reflex, the tonic labyrinthine reflex, and the Galant reflex) turned out to be statistically significantly different for the TD and DLD groups (p < .001). We also observed some differences between sexes.

Conclusions

Children with impaired language development underwent slower neuromotor development. 

Developmental language disorder (DLD) is observed in children whose language skills, for no clear reason, develop in a nontypical manner. Notably, such significant language difficulties are not accompanied by any serious cognitive, auditory, environmental, or neurological deficits (Bishop, 1992). It is estimated that approximately 7% of the population (Smoczyńska, 2006) will experience DLD, leading to long-term consequences for child development. The deficits that are characteristic of DLD persist into adolescence and may remain noticeable even in adulthood. Numerous studies have uncovered relationships between language deficits and other factors possibly caused by DLD, such as auditory processing disorder (Ferguson et al., 2011), deficits in phonological memory (Gathercole & Baddeley, 1993), delay in neurophysiological development manifesting in delayed cognitive and motor development (Adams, 2016; Bishop & Edmundson, 1987), and impairment of cognitive executive functions (Pauls & Archibald, 2016). According to various studies, consequences of DLD include learning difficulties (DeThorne et al., 2006; Fisher, 2017; Hulme & Snowling, 2009; Koutsoftas, 2016), poorer social interactions, and a lower position in one's peer group (Leonard, 2014).

Studies concerning the co-occurrence of DLD and motor immaturity have been conducted all over the world for more than 40 years, but they vary from one another in the different diagnostic tools used to assess the disorder. Nevertheless, children with DLD are assumed to differ from typically developing (TD) children as far as motor skills are concerned. For instance, quantitative differences occur in areas of motor development, such as gross motor skills (Chuang et al., 2011; Fernell et al., 2002; Iverson & Braddock, 2011; Müürsepp et al., 2011; Powell & Bishop, 1992; Zelaznik & Goffman, 2010), fine motor skills (Bishop & Edmundson, 1987; Brumbach & Goffman, 2014; Cheng et al., 2009; Chuang et al., 2011; Fernell et al., 2002; Owen & McKinlay, 1997; Powell & Bishop, 1992; Zelaznik & Goffman, 2010), general motor clumsiness (Robinson, 1991), balance (Estil et al., 2003; Fernell et al., 2002; Müürsepp et al., 2011; Powell & Bishop, 1992), bilateral coordination (Bishop, 1990; Estil et al., 2003; Vukovic et al., 2010; Vuolo et al., 2017), and imitation of positions and movements (Marton, 2009; Vukovic et al., 2010). According to one article review (Ullman & Pierpont, 2005), children with DLD—besides showing deficits on tests of fine and gross motor skills, limb mobility, coordination, and balance—showed impaired complex sequential motor skills, even when performing some motor tasks as precisely as TD children. Thus, it appears that, as far as motor development is concerned, children with DLD differ not only from TD children but also from children with articulation disorder (Müürsepp et al., 2012). Moreover, qualitative research has shown that children with DLD differ from TD children in terms of their pace of carrying out tasks, their precision, error complexity, ability to focus on motor tasks, and the relationship between accuracy of task performance and the degree of task complexity (Bishop & Edmundson, 1987; Marton, 2009; Powell & Bishop, 1992; Sanjeevan & Mainela-Arnold, 2017).