An automated two-choice test of olfactory working memory in the rat: Effect of scopolamine
Bibliographic record
Abstract
Experimenters have often employed visual and/or spatial stimuli to assess rodent working memory in delayed (non)matching-to-sample or delayed response paradigms. We present an automated task that uses olfactory stimuli to test working memory in the rat. Rats were trained on a continuous delayed two-choice working memory task in an operant olfactometer with four different delays (3, 30, 60, and 120 sec). The rats required a mean of 12 sessions to achieve a criterion of 80% correct on two consecutive days with a 3-sec delay. Baseline data revealed a significant mnemonic function, with performance decreasing at the longer delays. Despite this significant effect, rats reached levels of approximately 76% correct at a retention interval (delay) of 120 sec. When a stable baseline level of performance was reached, the effect of the central muscarinic antagonist scopolamine hydrobromide was assessed. Scopolamine caused a dose-dependent, delay-independent decrease in performance. This result supports previous findings with scopolamine in other tests of rodent working memory and demonstrates the sensitivity of the two-choice olfactory task to this robust cognitive effect. A rodent working memory paradigm bearing closer resemblance to common human and nonhuman primate tests of working memory than do the often employed delayed response procedures [e.g., delayed (non)matching to position] may be highly valuable in the study of the biological substrates of short-term/working memory. The present experiment demonstrates the utility of the two-choice olfactory working memory task, which is sensitive to increasing delays and anti-cholinergic treatment and is rapidly acquired by rats.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".