The placebo effect on psychomotor performance and working memory capacity: randomized single blind cross-over trial
Open accessAbstract
BACKGROUND: Imaging studies show that placebo enhance release of dopamine in the mesolimbic and mesocortical tracts. Dopamine in these areas are involved in attention and working memory function. PURPOSE: We wanted to investigating the effect of placebo on psychomotor function and working memory capacity. METHOD: 31 medical students participated in this single blind, crossover trial. Choice reaction time, critical flicker fusion threshold, n-back working memory tasks measured before and after one hour of the students receiving placebo in three different occasions as stimulant, unknown, and inert substance. RESULTS: Placebo, as stimulant, significantly enhanced choice reaction time and working memory function (P < 0.05) while showed no significant effect on critical flicker fusion threshold (P > 0.05). Placebo as unknown significantly deteriorates working memory capacity (P < 0.05). Placebo as inert substance shows no significant changes regarding choice reaction time, critical flicker fusion threshold, and working memory task. CONCLUSION: Placebo, as stimulant enhanced attention and improved working memory capacity, while as unknown may deteriorate working memory function.
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Outcome expectancies are central in the placebo response, in which individuals expect that pharmacological and other interventions will lead to beneficial outcomes.
“Outcome expectancies are central in the placebo response in which individuals expect that pharmacological and other interventions will lead to beneficial outcomes (Ashor, 2011;de la Fuente-Fernandez, 2009;Lidstone et al., 2010;Wager & Atlas, 2015).”
From Optimizing performance through intrinsic motivation and attention for learning: The OPTIMAL theory of motor learning (2016) · cites this paper as Ashor, 2011
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- Authors
- Ashor, A. W.
- Affiliations
- Mustansiriyah University (IQ)
- Corresponding author
- Ashor, Ammar W.
- ORCID
- Ashor, Ammar W.
- Venue
- Annals Of Neurosciences
- Publisher
- SAGE Publications
- Published
- 2011-08-19
- Volume
- 18
- Issue
- 4
- Pages
- 141-4
- ISSN
- 0972-7531 (ISSN-L)
- 0976-3260
- PMC
- PMC4116954
- OpenAlex
- W2081300752
- Cited by
- 12
- References
- 34
- Citations by year
- 2026: 1 · 2025: 2 · 2024: 2 · 2023: 1 · 2020: 3 · 2019: 1 · 2018: 1 · 2016: 1
- FWCI
- 0.00
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Annals of Neurosciences (publishedVersion)
- PubMed Central (publishedVersion)
- PubMed (publishedVersion)
- Funders
- Cystic Fibrosis Foundation Therapeutics
- Topics
- Life Sciences › Neuroscience › Cognitive Neuroscience › Pain Management and Placebo Effect
- Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neurotransmitter Receptor Influence on Behavior
- Life Sciences › Neuroscience › Cognitive Neuroscience › Neural and Behavioral Psychology Studies
- Keywords
- placebo effect, psychomotor performance, working memory capacity, choice reaction time, critical flicker fusion threshold, dopamine, mesolimbic system, mesocortical pathway, attention, medical students
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