Investigating the Interplay of Context, Cue, and Stimulus Competition in Affective Behaviours: Contributions of the Ventral Hippocampus and Medial Prefrontal Cortex
Bibliographic record
Abstract
The hippocampus (HPC) and medial prefrontal cortex (mPFC) have been heavily implicated in cue- and context-driven control of appetitively and aversively motivated behaviours. The ventral HPC (vHPC) and prelimbic (PL) subregion of the mPFC are critical for cue and contextual processing, and the infralimbic (IL) subregion of the mPFC is implicated in the extinction of these memories. However, data from both HPC and mPFC remain inconsistent with two major limitations: there is a lack of research examining the role of these regions in the appetitive control of behaviour utilizing natural reward, as most studies focus on drugs of abuse; and cue and context processing has largely been studied in isolation, despite often co-occurring in everyday life and giving rise to stimulus competition (SC), limiting the ecological validity of these findings. The purpose of this dissertation was two-fold. First, to elucidate the role of dorsal and ventral HPC and mPFC subregions (IL and PL) in contextual control of natural reward-seeking. Second, to develop a novel operant SC task to examine how overlapping cue and contextual information affect motivated behaviours and the involvement of the vHPC, IL and PL in these processes. In Chapters 2 and 3, we investigated the roles of the dorsal and ventral HPC, IL and PL in contextual biconditional discrimination (CBD) behaviour using a sucrose reward. We observed robust deficits in CBD performance following inactivation of the vHPC, IL and PL, but not the dorsal HPC. In Chapter 4, we developed a novel SC task to examine rodent behaviour in conditions where a cue previously associated with an outcome was superimposed on a context also previously (separately) associated with an outcome. In Chapter 5, we improved this task to enhance learning efficiency. Manipulations of the mPFC and vHPC yielded few significant effects. Overall, this work suggests a role for the vHPC and mPFC in contextual control of natural reward-seeking and provides insights into baseline behaviour in SC tasks, where contexts and elemental cues compete to control behaviour. These findings inform future research on animal models of comorbid disorders like PTSD and addiction, where approach-avoidance conflict is poorly understood.
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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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".