Using Primary Reinforcement to Enhance Translatability of a Human Affect and Decision-Making Judgment Bias Task

Abstract

Good translatability of behavioral measures of affect (emotion) between human and nonhuman animals is core to comparative studies. The judgment bias (JB) task, which measures “optimistic” and “pessimistic” decision-making under ambiguity as indicators of positive and negative affective valence, has been used in both human and nonhuman animals. However, one key disparity between human and nonhuman studies is that the former typically use secondary reinforcers (e.g., money) whereas the latter typically use primary reinforcers (e.g., food). To address this deficiency and shed further light on JB as a measure of affect, we developed a novel version of a JB task for humans using primary reinforcers. Data on decision-making and reported affective state during the JB task were analyzed using computational modeling. Overall, participants grasped the task well, and as anticipated, their reported affective valence correlated with trial-by-trial variation in offered volume of juice. In addition, previous findings from monetary versions of the task were replicated: More positive prediction errors were associated with more positive affective valence, a higher lapse rate was associated with lower affective arousal, and affective arousal decreased as a function of number of trials completed. There was no evidence that more positive valence was associated with greater “optimism,” but instead, there was evidence that affective valence influenced the participants' decision stochasticity, whereas affective arousal tended to influence their propensity for errors. This novel version of the JB task provides a useful tool for investigation of the links between primary reward and punisher experience, affect, and decision-making, especially from a comparative perspective.

From Pigs to Silkworms: Cognition and Welfare across 10 Farmed Taxa

“…For instance, judgement bias tasks in humans commonly use secondary reinforcers ( e.g ., money - see Neville et al 2021a) whereas judgement bias tasks in animals tend to use primary reinforcers ( e.g ., food - see Neville et al 2020), making it challenging to compare results. Studies on humans should aim to use primary reinforcers ( e.g ., juice/salty tea) to make judgement bias tasks translatable between humans and animals (Neville et al 2021b). By designing a series of translatable tasks, we can better draw conclusions about susceptibility to cognitive bias across taxa in the future.…”

A primer on the use of computational modelling to investigate affective states, affective disorders and animal welfare in non-human animals

“…For example, poor learning about negative outcomes could lead to a vicious cycle of an individual not being able to predict, and so repeatedly being surprised by, aversive outcomes, leading to generation of negative prediction errors and an associated persistent negative mood (Eldar et al, 2016 ). Computational studies have demonstrated a link between prediction errors and self-reported mood: more positive prediction errors are associated with a more positive report of mood, and vice versa (Neville et al, 2021a , c ; Otto & Eichstaedt, 2018 ; Rutledge et al, 2014 ). In a similar vein, it has been suggested that depression may arise when an individual has a strong belief that they inhabit a volatile world leading to poor allostatic regulation; trying to anticipate future needs is futile when there is such uncertainty (Clark et al, 2018 ).…”

Rodent tests of depression and anxiety: Construct validity and translational relevance

“…Importantly, cognitive affective bias studies in humans following similar protocols to rodent experiments yielded comparable results (Anderson et al, 2012 ; Iigaya et al, 2016 ; Mendl et al, 2006 ; Schick et al, 2013 ). While earlier human studies utilized secondary reinforcers, such as monetary rewards, a recent study (Neville et al, 2021 ) directly applied the animal JBT to humans, employing food as the primary reinforcer, and uncovered an association between positive biases and positive affect in humans. These findings led to the consideration of the judgement bias test as the “gold standard” to assess affective states in nonhuman animals (Bateson & Nettle, 2015 ).…”