University of Groningen, The Netherlands
Doctoral defence of M.A. Elina Hakkarainen
The field of science of the dissertation is Psychology.
The opponent is docent Kaisa Hartikainen (University of Tampere). Docent Silja Pirilä acts as the custos.
The language of the dissertation defence is English.
Cognitive and motor processing in mild spastic cerebral palsy: An event-related potential study
The incidence of Cerebral palsy (CP) is approximately 2 per 1000 live births, which makes it the most common motor impairment in children. CP is a motor disorder often accompanied by cognitive deficits. The spastic subtype is the most common type (66 % - 82 %) of all cases, and abnormalities in attention, working memory, and executive functions are common clinical observations in this group. However, the neuromotor disability and communication problems in people with cerebral palsy challenge the use of standard neuropsychological tests: the use of these traditional test methods may lead to an over- or under-evaluation of their true cognitive abilities. Event-related potential (ERP) methodology offers the possibility to evaluate cognitive abilities apart from motor skills with a high temporal accuracy. The present series of ERP studies investigated cognitive and motor processing in youth with mild spastic cerebral palsy. Attention, working memory, and executive functions were evaluated in an oddball task and in a memory search task.
Study I showed that fundamental attention processes (orientation and evaluation of stimulus novelty) were intact in youth with mild spastic cerebral palsy when measured in a condition requiring no overt reactions.
In Study II, findings indicated an overall slowness and lower performance accuracy in youth with mild spastic cerebral palsy. An event-related potential analysis revealed that the stimulus evaluation processing was intact in the group of patients. Also event preparation and action planning were intact in the group of patients. It was concluded that patients’ motor slowness reflected poor motor execution processes.
In study III, findings indicated that error responses in youth with mild spastic cerebral palsy were associated with weak motor preparation. However, patients were detecting their errors and thus improved their performance in next trial. The results suggest that the consequence of error making on future performance is intact in the sample of youth with mild spastic cerebral palsy.
In study IV, it was found that error making was foreshadowed by a decrease in stimulus evaluation in the patient group and in the control group. Further, altered motor preparation for erroneous responses discovered in study III was perceived already in the correct trial directly preceding an error. It was concluded that although the patient group showed intact stimulus and response evaluation capacity, their weaker behavioral outcomes (slower response times and pronounced error rates) in comparison to controls reflected difficulties in motor processes, namely, disturbances in poor motor execution processes and fluctuations in motor presetting.
This dissertation is jointly supervised with the Univeristy of Groningen (the Netherlands) and the University of Tampere (Cotutelle).
The dissertation is published by the University of Groningen. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1786, Tampere University Press 2017.
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