Unimpaired implicit learning in children with developmental dyslexia

Abstract

Children with dyslexia have consistently been found to have a variety of deficits in motor, cognitive, and sensory processes; however, the few studies that have been reported of the implicit learning ability of these children have produced conflicting results. The present study aimed to investigate the implicit learning abilities of children with developmental dyslexia using a simple cued reaction time task which has not been studied with this group previously. Twenty-three children with developmental dyslexia and 37 normally developing children, between the ages of 8 and 10 years, participated in the task. The results were consistent with the hypothesis in demonstrating that, despite an overall slowing in response times, dyslexic children show the same degree of implicit learning as normal readers, thus, providing evidence for an unimpaired implicit learning mechanism in dyslexic individuals. These results hold implications for the underlying mechanisms of learning, as dyslexic individuals who are impaired on explicit learning tasks, such as reading, spelling and writing, are unimpaired on implicit learning tasks. They suggest the existence of two separate systems of learning, each possessing distinct mechanisms.

Do children with developmental dyslexia have impairments in implicit learning?

“…mirror drawing), found a diminished performance of children with developmental dyslexia. On the contrary, Roodenrys and Dunn (2007) using a simple SRTT found intact implicit learning performance in children with developmental dyslexia. Taken together the studies suggest that implicit learning abilities are found impaired in children with developmental dyslexia when (1) explicit learning abilities are intact (Vicari et al, 2003) and (2) when the complexity of the learning environment is increased (Vicari et al, 2005) irrespective of the learning materials (Folia et al, 2008).…”

“…Overall, the studies provide evidence that while some implicit learning abilities remain robust (Roodenrys & Dunn, 2007) in children with developmental dyslexia, others are affected (Vicari et al, 2003(Vicari et al, , 2005. More specifically, Vicari et al (2003) found impaired implicit sequence learning in school-aged children with developmental dyslexia despite intact explicit learning abilities.…”

“…Taken together the studies suggest that implicit learning abilities are found impaired in children with developmental dyslexia when (1) explicit learning abilities are intact (Vicari et al, 2003) and (2) when the complexity of the learning environment is increased (Vicari et al, 2005) irrespective of the learning materials (Folia et al, 2008). On the contrary, implicit learning abilities seem to be spared in less complex learning environments (Roodenrys & Dunn, 2007).…”

“…The discrepancy in the findings of implicit learning and developmental dyslexia using the SRTT suggests that different research paradigms could tap into different implicit learning processes (Roodenrys & Dunn, 2007). It also raises the question of whether children with developmental dyslexia will show a similar performance compared to typically developing children under a different and more highly complex implicit learning paradigm.…”

“…Vicari et al, 2005). The majority of the studies (Roodenrys & Dunn, 2007;Vicari, Marrota, Menghini, Molinari, & Petrosini, 2003;Vicari et al, 2005) make use of the serial reaction time task (SRTT) (Benett, Romano, Howard, & Howard, 2008;Howard et al, 2006;Stoodley, Harrison, & Stein, 2006;Stoodley, Ray, Jack, & Stein, 2008).This paradigm is used in its original form (Roodenrys & Dunn, 2007) or in an alternated one in terms of procedure manipulations (Vicari et al, 2003). It is also used solely or in combination with another implicit (Vicari et al, 2003) or explicit learning task (Vicari et al, 2005).…”