Working memory training increases neural efficiency in Parkinson's disease: a randomized controlled trial

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Parkinson's disease (PD) frequently impairs working memory and executive functions early on.
• Neural mechanisms of working memory subprocesses (maintenance vs. manipulation) are under-investigated in PD.
• The plasticity of neural correlates with working memory training in PD is unknown.

Purpose of the Study:

• To investigate neural mechanisms of working memory maintenance and manipulation in PD.
• To assess the impact of a 5-week working memory training intervention on these neural mechanisms.
• To explore changes in brain activation and functional connectivity post-training.

Main Methods:

• Functional MRI (fMRI) and a novel working memory paradigm were used.
• 41 cognitively healthy PD patients were assessed.
• 19 patients underwent a 5-week home-based digital working memory training; 22 were controls.

Main Results:

• Both maintenance and manipulation activated frontoparietal-cerebellar networks; manipulation additionally recruited the anterior striatum.
• Training led to small, significant decreases in task-related activation, correlating with behavioral improvements.
• Functional connectivity showed decreased patterns for maintenance and reorganization for manipulation post-training.

Conclusions:

• Working memory training in PD induces neural changes, supporting the neural efficacy hypothesis.
• Training alters activation and functional connectivity differentially for maintenance and manipulation.
• Larger trials are needed to confirm long-term effects and clinical relevance for delaying cognitive decline.