Evidence map›Paper›PMID 31015587›Full record

Trial reportScientific reports2019

Levodopa does not affect expression of reinforcement learning in older adults.

J P Grogan, H K Isotalus, A Howat, N Irigoras Izagirre, L E Knight, E J Coulthard

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Scientific reports, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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.

2 · The registry

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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

J P GroganUniversity of Bristol, Bristol, UK. john.grogan@bristol.ac.uk.ORCID http://orcid.org/0000-0002-0463-8904
H K IsotalusUniversity of Bristol, Bristol, UK.ORCID http://orcid.org/0000-0002-3393-9263
A HowatUniversity of Bristol, Bristol, UK.
N Irigoras IzagirreUniversity of Bristol, Bristol, UK.
L E KnightUniversity Hospitals Bristol, Bristol, UK.
E J CoulthardUniversity of Bristol, Bristol, UK. Elizabeth.coulthard@bristol.ac.uk.

Funding

Medical Research CouncilWellcome TrustWellcome Trust (Wellcome) 097081/Z/11/Z
6 · The paper itself

Abstract

Dopamine has been implicated in learning from rewards and punishment, and in the expression of this learning. However, many studies do not fully separate retrieval and decision mechanisms from learning and consolidation. Here, we investigated the effects of levodopa (dopamine precursor) on choice performance (isolated from learning or consolidation). We gave 31 healthy older adults 150 mg of levodopa or placebo (double-blinded, randomised) 1 hour before testing them on stimuli they had learned the value of the previous day. We found that levodopa did not affect the overall accuracy of choices, nor the relative expression of positively or negatively reinforced values. This contradicts several studies and suggests that overall dopamine levels may not play a role in the choice performance for values learned through reinforcement learning in older adults.

Indexed as

Reinforcement, PsychologyAgedBayes TheoremChoice BehaviorFemaleHumansLearningLevodopaMaleLevodopa

Identifiers

PMID31015587
PMCPMC6478852

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.