Related Experiment Videos
Dopamine agonists reorient visual exploration away from the neglected hemispace
Z Grujic1, M Mapstone, D R Gitelman
1Cognitive Neurology and Alzheimer's Disease Center, Department of Neurology, Northwestern University Medical School, Chicago, IL 60611, USA.
Neurology
|November 18, 1998
Summary
Bromocriptine, a dopamine agonist, worsened visual neglect in patients with brain lesions by increasing exploration of one side of space. Target detection accuracy remained unchanged, indicating a specific impact on attention rather than perception.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Pharmacology
Background:
- Spatial attention relies on a distributed brain network including cortical and subcortical regions.
- Dopamine plays a crucial role in modulating this attention network's function.
Purpose of the Study:
- To investigate the impact of bromocriptine, a dopamine agonist, on visual search performance.
- To understand how dopamine modulation affects spatial attention components.
Main Methods:
- Seven right-handed subjects with right-sided cerebral lesions participated.
- A computerized target search task was employed to assess visual search.
- Eye movements were meticulously recorded to analyze search patterns.
Main Results:
- Bromocriptine administration led to increased exploration of the ipsilesional hemispace.
- A relative neglect of the contralesional (left) hemispace was observed.
- Crucially, target detection accuracy remained unaffected by bromocriptine.
Conclusions:
- Bromocriptine can exacerbate hemispatial neglect symptoms in patients with specific brain lesions.
- The drug differentially affects exploratory-motor and sensory-perceptual aspects of directed attention.
- Findings suggest bromocriptine's impact on postsynaptic dopaminergic pathways contributes to neglect worsening.