An ERP investigation of premotor sensory activity and response control in adults with Developmental Coordination Disorder.

Abstract

Within the Developmental Coordination Disorder (DCD) literature the primary research focus has been directed towards children with DCD. Little has been investigated regarding the long term prognosis of these individuals with regards to the impact of the disorder in later life. Also, previous investigations and resulting suggestions of underlying aetiology have been based on behavioural data of poor performance with few studies examining the underlying biological considerations. Thus, the research within this thesis had two key aims. The first being to examine underlying processes associated with adaptive and goal directed movement in a sample of adults with DCD. The second aim was to provide biological evidence for the continued difficulties of adults with DCD. Previous work in the area of cognitive psychology has identified distinct sensory and motor control functions as hallmarks of efficient and adaptive movement. This thesis explores the underlying sensory and motor control abilities of adults with DCD. There were two key aspects of this thesis with the first consisting of an investigation into the manner in which adults with DCD utilize sensory functions as a consequence of movement preparation. The secondary portion of this thesis focused on two key aspects of response modulation, the ability to effectively activate cortical regions underpinning effector response and response inhibition. Both aspects of the thesis drew methodological influences from the field of electroencephalography. This approach provided direct biological measurement of both sensory and response related activity. The data obtained within this thesis provides evidence that adults with DCD do in fact demonstrate both atypical behavioural and biological functions during manual response activity. Chapter 4 highlighted key behavioural findings identifying that the DCD group demonstrates continued difficulty with accurate movement compared to typically developing peers. Chapters 5 and 6 focused on sensory activity as a consequence of movement preparation. The findings from these chapters suggest that adults with DCD present with maladaptive early sensory processing functions required for accurate movement output. Findings from the later chapters investigating response related activity suggest that adults with DCD experience difficulty with both measures of response activation and inhibition. In summary, these findings suggest that adults with DCD experience an array of sensorimotor and response related difficulties vital to adaptive goal directed movement. Importantly, the findings presented within this thesis are the first to present direct biological based evidence for continued difficulties in a sample of adults with DCD. Conclusions are discussed in relation to previous research along with the possible influences these findings have in behaviour. The limitations of the current research and suggestions for future work are also considered