title: Diffusion Modelling Reveals the Decision Making Processes Underlying Negative Judgement Bias in Rats.
abstract: Human decision making is modified by emotional state. Rodents exhibit similar biases during interpretation of ambiguous cues that can be altered by affective state manipulations. In this study, the impact of negative affective state on judgement bias in rats was measured using an ambiguous-cue interpretation task. Acute treatment with an anxiogenic drug (FG7142), and chronic restraint stress and social isolation both induced a bias towards more negative interpretation of the ambiguous cue. The diffusion model was fit to behavioural data to allow further analysis of the underlying decision making processes. To uncover the way in which parameters vary together in relation to affective state manipulations, independent component analysis was conducted on rate of information accumulation and distances to decision threshold parameters for control data. Results from this analysis were applied to parameters from negative affective state manipulations. These projected components were compared to control components to reveal the changes in decision making processes that are due to affective state manipulations. Negative affective bias in rodents induced by either FG7142 or chronic stress is due to a combination of more negative interpretation of the ambiguous cue, reduced anticipation of the high reward and increased anticipation of the low reward.
authors.affiliation: School of Physiology and Pharmacology, Faculty of Biomedical Sciences, University of Bristol, Bristol, BS8 1TD, United Kingdom.
authors.forename: Claire A
authors.initials: CA
authors.lastname: Hales
authors.affiliation: School of Physiology and Pharmacology, Faculty of Biomedical Sciences, University of Bristol, Bristol, BS8 1TD, United Kingdom.
authors.forename: Emma S J
authors.initials: ES
authors.lastname: Robinson
authors.affiliation: Department of Computer Science, Faculty of Engineering, University of Bristol, Bristol, BS8 1UB, United Kingdom.
authors.forename: Conor J
authors.initials: CJ
authors.lastname: Houghton
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D015982:Bias; D003657:Decision Making; D004058:Diffusion; D007600:Judgment; D008297:Male; D008962:Models, Theoretical; D025341:Principal Component Analysis; D051381:Rats; D015203:Reproducibility of Results; D013647:Task Performance and Analysis