The involvement of dopamine neurotransmission in mood in humans: Administration of L-3,4-dihydroxyphenylalanine to healthy volunteers
Bibliographic record
Abstract
A large body of evidence indicates that dopamine (DA) neurotransmission regulates approach toward rewards and reward-related cues. The best-cited hypothesis proposes that DA accomplishes this by mediating the pleasurable effects of a variety of natural and drug rewards. This "anhedonia hypothesis" has received support from some pre-clinical models of reward and a few drug challenge studies in humans. However, direct assessment of DA's role in mood and other subjective states in healthy humans has been largely limited to the use of psychostimulant drugs, which elevate brain levels of multiple neurotransmitters in addition to DA. This thesis is comprised of one study which examined the effect of more selectively elevated DA neurotransmission, as produced by administration of the immediate DA precursor, L-DOPA, in healthy human volunteers. L-DOPA failed to alter mood and other subjective states. These results add to the evidence that DA neurotransmission does not directly influence mood in healthy humans.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".