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Space-based inhibition of return in children with spina bifida
Maureen Dennis1, Kim Edelstein, Kim Copeland
1Brain and Behaviour Program, The Hospital for Sick Children, Toronto, ON, Canada. maureen.dennis@sickkids.ca.
Insights
Children with spina bifida meningomyelocele (SBM) exhibit impaired inhibition of return (IOR), a visual attention deficit. This deficit is linked to midbrain structural abnormalities, impacting their ability to orient attention.
Area of Science:
- Neuroscience
- Developmental Psychology
- Ophthalmology
Background:
- Inhibition of return (IOR) is a fundamental aspect of visual attention, reflecting delayed target detection at previously attended locations.
- Children with spina bifida meningomyelocele (SBM) often present with congenital midbrain dysmorphology, a region critical for attentional control.
- IOR deficits have been observed in various neurological conditions, suggesting a role for specific brain structures in its mediation.
Purpose of the Study:
- To investigate inhibition of return (IOR) in children and adolescents with spina bifida meningomyelocele (SBM).
- To examine the association between IOR performance and midbrain structural abnormalities in this population.
- To explore potential deficits in attentional orienting to salient stimuli in SBM.
Main Methods:
- A cohort of 84 children and adolescents with SBM and 37 typically developing controls (ages 8–19) participated.
- Exogenously cued covert orienting was assessed using a peripheral luminance change cue with 50% validity.
- Midbrain morphology, including tectal beaking and posterior brain volume, was evaluated using neuroimaging techniques.
Main Results:
- Children with SBM demonstrated significantly attenuated IOR in the vertical plane compared to controls.
- This IOR deficit in SBM was correlated with midbrain dysmorphology, specifically tectal beaking.
- No association was found between the IOR deficit and posterior brain volume loss in the SBM group.
Conclusions:
- The findings indicate that children with SBM exhibit specific deficits in visual attention, particularly in inhibition of return.
- Midbrain structural abnormalities, such as tectal beaking, are implicated in the observed attentional orienting impairments in SBM.
- This study contributes to the growing body of evidence highlighting attentional processing challenges in individuals with spina bifida.
Abstract:
Inhibition of return (IOR) refers to an increase in time to react to a target in a previously attended location. Children with spina bifida meningomyelocele (SBM) and hydrocephalus have congenital dysmorphology of the midbrain, a brain region associated with the control of covert orienting in general and with IOR in particular. The authors studied exogenously cued covert orienting in 8- to 19-year-old children and adolescents (84 with SBM and 37 age-matched, typically developing controls). The exogenous cue was a luminance change in a peripheral box that was 50% valid for the upcoming target location. Compared with controls, children with SBM showed attenuated IOR in the vertical plane, a deficit that was associated with midbrain dysmorphology in the form of tectal beaking but not with posterior brain volume loss. The data add to the emerging evidence for SBM deficits in attentional orienting to salient information.
