Unravelling developmental disregard in children with unilateral cerebral palsy by measuring event-related potentials
Ingar M Zielinski1, Marijtje L A Jongsma, C Marjolein Baas
1Behavioural Science Institute, Radboud University Nijmegen, PO Box 9104, 6500, HE Nijmegen, The Netherlands. i.zielinski@pwo.ru.nl.
Insights
Children with Developmental Disregard (DD) in unilateral Cerebral Palsy (CP) show increased cognitive load when preparing movements with their affected hand during dual-hand tasks, as evidenced by electrophysiological findings.
Area of Science:
- Neuroscience
- Developmental Pediatrics
- Rehabilitation Medicine
Background:
- Unilateral Cerebral Palsy (CP) in children can present with Developmental Disregard (DD), a discrepancy between upper limb capacity and performance.
- The underlying causes of DD are debated, with theories including operant conditioning and increased cognitive load due to diminished motor automaticity.
Purpose of the Study:
- To investigate the cognitive load associated with DD by studying Event-Related Potentials (ERPs) during motor tasks.
- To differentiate between capacity and performance in the affected upper limb in children with DD.
Main Methods:
- Studied 14 children with unilateral CP (7 with DD, 7 controls) using a cue-target paradigm.
- Compared ERPs (P2 and N2b components) during single-hand capacity and dual-hand performance tasks.
Main Results:
- Children with DD exhibited enhanced N2b component amplitude when preparing responses with the affected hand in the dual-hand task.
- No significant differences in P2 amplitude or during the single-hand capacity task were observed.
- Control group showed no differences in ERPs between hands.
Conclusions:
- DD is linked to increased cognitive load during affected hand movement preparation in dual-hand tasks.
- Electrophysiological data support behavioral observations and offer insights into the neural basis of DD.
- Findings have implications for therapeutic interventions in CP.
Background:
In a subset of children with unilateral Cerebral Palsy (CP) a discrepancy between capacity and performance of the affected upper limb can be observed. This discrepancy is known as Developmental Disregard (DD). Though the phenomenon of DD has been well documented, its underlying cause is still under debate. DD has originally been explained based on principles of operant conditioning. Alternatively, it has been proposed that DD results from a diminished automaticity of movements, resulting in an increased cognitive load when using the affected hand. To investigate the amount of involved cognitive load we studied Event-Related Potentials (ERPs) preceding task-related motor responses during a single-hand capacity and a dual-hand performance task. It was hypothesised that children with DD show alterations related to long-latency ERP components when selecting a response with the affected upper limb, reflecting increased cognitive load in order to generate an adequate response and especially so within the dual-hand task.
Methods:
Fifteen children with unilateral CP participated in the study. One of the participants was excluded due to major visual impairments. Seven of the remaining participants displayed DD. The other seven children served as a control group. All participants performed two versions of a cue-target paradigm, a single-hand capacity and a dual-hand performance task. The ERP components linked to target presentation were inspected: the mid-latency P2 component and the consecutive long-latency N2b component.
Results:
In the dual-hand performance task children with DD showed an enhancement in mean amplitude of the long-latency N2b component when selecting a response with their affected hand. No differences were found regarding the amplitude of the mid-latency P2 component. No differences were observed regarding the single-hand capacity task. The control group did not display any differences in ERPs linked to target evaluation processes between both hands.
Conclusion:
These electrophysiological findings show that DD is associated with increased cognitive load when movements are prepared with the affected hand during a dual-hand performance task. These findings confirm behavioural observations, advance our insights on the neural substrate of DD and have implications for therapy.
