ArticlePsychopharmacology2018
Effects of Parkinson's disease and dopamine on digit span measures of working memory.
Article in Psychopharmacology, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 20 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
20 citing papers in PubMed, 1 synthesis or guideline pooled it.
- A Comprehensive Meta-analysis on Short-term and Working Memory Dysfunction in Parkinson's Disease.Neuropsychology review · 2021Pooled it
- Theta tACS Over the Medial Frontal Cortex Modulates Executive Function in Parkinson's Disease: A Randomized, Sham-Controlled Study.CNS neuroscience & therapeutics · 2026Trial
- KICK OUT PD: Feasibility and quality of life in the pilot karate intervention to change kinematic outcomes in Parkinson's Disease.PloS one · 2020Trial
- Levodopa does not affect expression of reinforcement learning in older adults.Scientific reports · 2019Trial
- Development and Preliminary Validation of ORCA-PD, an Online Rapid Cognitive Assessment for Parkinson Disease: Mixed Methods Study.Journal of medical Internet research · 2026Article
- The Effect of Stress on Working Memory in Persons with Parkinson's Disease.Brain sciences · 2026Article
- Subthalamic stimulation modulates working memory-related cortical dynamics in Parkinson's disease.Brain communications · 2026Article
- Attention/Working Memory and Executive Function in Parkinson's Disease: Review, Critique, and Recommendations.Movement disorders : official journal of the Movement Disorder Society · 2025Review
- Selective Effects of Substantia Nigra and Locus Coeruleus Degeneration on Cognition in Parkinson's Disease.Movement disorders : official journal of the Movement Disorder Society · 2025Article
- Differences in cognitive deficits and brain functional impairments between patients with first-episode and recurrent depression.BMC psychiatry · 2025Article
- Impaired sequence manipulation in non-demented patients with progressive supranuclear palsy.Brain and behavior · 2024Article
- Exploring Working Memory Capacity and Efficiency Processes to Understand Working Memory Training Outcomes in Primary School Children.Journal of cognition · 2024Article
- Theory of mind deficits in Parkinson's disease are not modulated by dopaminergic medication.Frontiers in neurology · 2023Article
- Effects of cholinesterase inhibition on attention and working memory in Lewy body dementias.Brain communications · 2023Article
- Restorative Effects of Observing Natural and Urban Scenery after Working Memory Depletion.International journal of environmental research and public health · 2022Article
- Virtual Reality-based Cognitive Intervention for Enhancing Executive Functions in Community-dwelling Older Adults.Psychosocial intervention · 2022Article
- Elevated Dopamine Synthesis as a Mechanism of Cognitive Resilience in Aging.Cerebral cortex (New York, N.Y. : 1991) · 2022Article
- Dopamine effects on memory load and distraction during visuospatial working memory in cognitively normal Parkinson's disease.Neuropsychology, development, and cognition. Section B, Aging, neuropsychology and cognition · 2021Article
- Dopamine D2R is Required for Hippocampal-dependent Memory and Plasticity at the CA3-CA1 Synapse.Cerebral cortex (New York, N.Y. : 1991) · 2021Article
- The Effects of Working Memory Updating Training in Parkinson's Disease: A Feasibility and Single-Subject Study on Cognition, Movement and Functional Brain Response.Frontiers in psychology · 2020Article
Corrections and comments
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Authors and funding
9 authors.
Funding
Abstract
rationaleParkinson's disease (PD) impairs working memory (WM)-the ability to maintain items in memory for short periods of time and manipulate them. There is conflicting evidence on the nature of the deficits caused by the disease, and the potential beneficial and detrimental effects of dopaminergic medication on different WM processes.
objectivesWe hypothesised that PD impairs both maintenance and manipulation of items in WM and dopaminergic medications improve this in PD patients but impair it in healthy older adults.
methodsWe tested 68 PD patients ON and OFF their dopaminergic medication, 83 healthy age-matched controls, and 30 healthy older adults after placebo and levodopa administration. We used the digit span, a WM test with three components (forwards, backwards, and sequence recall) that differ in the amount of manipulation required. We analysed the maximum spans and the percentage of lists correctly recalled, which probe capacity of WM and the accuracy of the memory processes within this capacity, respectively.
resultsPD patients had lower WM capacity across all three digit span components, but only showed reduced percentage accuracy on the components requiring manipulation (backwards and sequence spans). Dopaminergic medication did not affect performance in PD patients. In healthy older adults, levodopa did not affect capacity, but did impair accuracy on one of the manipulation components (sequence), without affecting the other (backwards).
conclusionsThis suggests that the deficit of maintenance capacity and manipulation accuracy in PD patients is not primarily a dopaminergic one and supports a potential "overdosing" of intact manipulation mechanisms in healthy older adults by levodopa.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.