[Show abstract][Hide abstract] ABSTRACT: A dysfunction in predictive motor timing is put forward to underlie DCD-related motor problems. Predictive timing allows for the pre-selection of motor programmes (except 'program' in computers) in order to decrease processing load and facilitate reactions. Using functional magnetic resonance imaging (fMRI), this study investigated the neural correlates of motor timing in DCD (n=17) and typically developing children (n=17). The task involved motor responses to sequences of visual stimuli with predictive or unpredictive interstimulus intervals (ISIs). DCD children responded with a smaller reaction time (RT) advantage to predictive ISIs compared to typically developing children. Typically developing children exhibited higher activation in the right dorsolateral prefrontal cortex (DLPFC) and right inferior frontal gyrus (IFG) for responses at unpredictive as opposed to predictive ISIs, whereas activations in DCD children were non-differentiable. Moreover, DCD children showed less activation than typically developing children in the right DLPFC, the left posterior cerebellum (crus I) and the right temporo-parietal junction (TPJ) for this contrast. Notably, activation in the right temporo-parietal junction (TPJ) positively correlated with RT as an indicator of processing load in both groups. These data indicate that motor performance in DCD children requires extra processing demands due to impaired predictive encoding.
Research in developmental disabilities 03/2013; 34(5):1478-1487. · 4.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Predictive timing refers to the anticipation and precise timing of planned motor responses. This study was performed to investigate children's predictive response timing abilities while accounting for confounding age-related effects of motor speed. Indices of predictive timing were evaluated for their contributions in motor skill proficiency as well. Eighty typically developing children in 4 age groups (5-6, 7-8, 9-10 and 11-12years) performed a visuomotor reaction time (RT) test. Differences in speed and anticipatory responding at regularly relative to irregularly paced stimuli were evaluated as indices of predictive timing. Also, explicit timing and motor tests (M-ABC-2, VMI tracing, and KTK jumping) were administered. Significant faster responding for regularly versus irregularly paced stimuli was found from the ages of 9-10years on. Better anticipatory responding behavior for regular in contrast with irregular stimuli was found to be present already at 7-8years. Overall, predictive timing abilities increased across the 4 age groups. Also, inter-individual differences in the speed indices of predictive timing contributed to predicting VMI tracing and KTK jumping outcomes when controlling for age and overall motor response speed. In conclusion, predictive motor timing abilities increase during age 5 to 12 and correlate with motor skill performance.
Human movement science 04/2012; · 2.15 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although current theories all point to distinct neural systems for sequence learning, no consensus has been reached on which factors crucially define this distinction. Dissociable judgment-linked versus motor-linked and implicit versus explicit neural systems have been proposed. This paper reviews these two distinctions, yet concludes that these traditional dichotomies prove insufficient to account for all data on sequence learning and its neural organization. Instead, a broader theoretical framework is necessary providing a more continuous means of dissociating sequence learning systems. We argue that a more recent theory, dissociating multidimensional versus unidimensional neural systems, might provide such framework, and we discuss this theory in relation to more general principles of associative learning and recent imaging findings.
Advances in Cognitive Psychology 01/2012; 8(2):73-82.
[Show abstract][Hide abstract] ABSTRACT: The defining feature of Developmental Coordination Disorder (DCD) is the marked impairment in the development of motor coordination (DSM-IV-TR, American Psychiatric Association, 2000). In the current study, we focused on one core aspect of motor coordination: learning to correctly sequence movements. We investigated the procedural, visuo-motor sequence learning abilities of 18 children with DCD and 20 matched typically developing (TD) children, by means of the serial reaction time (SRT) task. Reaction time measurements yielded two important findings. Overall, DCD children demonstrated general learning of visuo-motor task demands comparable to that of TD children but failed to learn the visuo-motor sequence. Interestingly, a sequence recall test, administered after the SRT task, indicated some awareness of the repeating sequence pattern. This suggests that the sequence learning problems of DCD children might be located at the stage of motor planning rather than sequence acquisition.
Research in developmental disabilities 01/2011; 32(2):749-56. · 4.41 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present fMRI study investigated the neural areas involved in implicit perceptual sequence learning. To obtain more insight in the functional contributions of the brain areas, we tracked both the behavioral and neural time course of the learning process, using a perceptual serial color matching task. Next, to investigate whether the neural time course was specific for perceptual information, imaging results were compared to the results of implicit motor sequence learning, previously investigated using an identical serial color matching task (Gheysen et al., 2010). Results indicated that implicit sequences can be acquired by at least two neural systems: the caudate nucleus and the hippocampus, having different operating principles. The caudate nucleus contributed to the implicit sequence learning process for perceptual as well as motor information in a similar and gradual way. The hippocampus, on the other hand, was engaged in a much faster learning process which was more pronounced for the motor compared to the perceptual task. Interestingly, the perceptual and motor learning process occurred on a comparable implicit level, suggesting that consciousness is not the main determinant factor dissociating the hippocampal from the caudate learning system. This study is not only the first to successfully and unambiguously compare brain activation between perceptual and motor levels of implicit sequence learning, it also provides new insights into the specific hippocampal and caudate learning function.
Frontiers in Human Neuroscience 01/2011; 5:137. · 2.91 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Implicit motor sequence learning refers to an important human ability to acquire new motor skills through the repeated performance of a motor sequence. This learning process is characterized by slow, incremental gains of motor performance. The present fMRI study was developed to better delineate the areas supporting these temporal dynamics of learning. By using the serial color matching paradigm, our study focused on the motor level of sequence learning and tracked the time course of learning-related neural changes. Imaging results showed a significant contribution of the left anterior hippocampus in an early sequence acquisition stage (first scanning session) as well as during a later stage with stabilized learning effects (second scanning session). Hippocampal activation significantly correlated with the behavioral learning process and was affected by a change of the motor sequence. These results suggest a strong involvement of the hippocampus in implicit motor sequence learning. On the other hand, a very extensive and bilateral neural network of parietal, temporal and frontal cortical areas (including SMA, pre-SMA) together with parts of the cerebellum and striatum were found to play a role during random visuo-motor task performance.
Experimental Brain Research 02/2010; 202(4):795-807. · 2.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This paper contributes to the domain of implicit sequence learning by presenting a new version of the serial reaction time (SRT) task that allows unambiguously separating perceptual from motor learning. Participants matched the colors of three small squares with the color of a subsequently presented large target square. An identical sequential structure was tied to the colors of the target square (perceptual version, Experiment 1) or to the manual responses (motor version, Experiment 2). Short blocks of sequenced and randomized trials alternated and hence provided a continuous monitoring of the learning process. Reaction time measurements demonstrated clear evidence of independently learning perceptual and motor serial information, though revealed different time courses between both learning processes. No explicit awareness of the serial structure was needed for either of the two types of learning to occur. The paradigm introduced in this paper evidenced that perceptual learning can occur with SRT measurements and opens important perspectives for future imaging studies to answer the ongoing question, which brain areas are involved in the implicit learning of modality specific (motor vs. perceptual) or general serial order.
Experimental Brain Research 07/2009; 197(2):163-74. · 2.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to investigate the impact of a cochlear implant (CI) on the motor development of deaf children. The study involved 36 mainstreamed deaf children (15 boys, 21 girls; 4- to 12-years old) without any developmental problems. Of these children, 20 had been implanted. Forty-three hearing children constituted a comparison group. Motor development was assessed by three standardized tests: the Movement Assessment Battery for Children, the Körperkoordinationstest für Kinder, and the One-leg standing test. Results showed that the hearing children performed on average significantly better than the deaf children (whether or not using a CI). Regarding the use of a CI, there was only a significant difference on one subtest between both groups, although there was a nonsignificant trend for the deaf +CI group to score somewhat worse on average than the deaf -CI group. This led to some significant differences between the hearing group and the deaf +CI group on measures requiring balance that did not hold for the hearing/deaf -CI comparison. Although this study could demonstrate neither a positive nor a negative impact of CI on balance and motor skills, the data raise the need for further, preferably longitudinal, research.
Journal of Deaf Studies and Deaf Education 02/2008; 13(2):215-24. · 1.02 Impact Factor