Attentional responses to stimuli associated with a reward can occur in the absence of knowledge of their predictive values

Abstract

Classical conditioning theories of addiction suggest that stimuli associated with rewards acquire incentive salience, inducing emotional and attentional conditioned responses. It is not clear whether those responses occur without contingency awareness (CA), i.e. are based on explicit or implicit learning processes. Examining implicit aspects of stimulus-reward associations can improve our understanding of addictive behaviours, supporting treatment and prevention strategies. However, the acquisition of conditioned responses without CA has yet to be rigorously demonstrated, as the existing literature shows a lack of methodological agreement regarding the measurement of implicit and explicit processes. The purpose of two experiments presented here was to study the emotional value acquired by CS through implicit emotional and attentional processes, trying to overcome critical methodological issues. Experiment 1 (n = 48) paired two stimuli categories (houses/buildings) with high (HR) or low (LR) probabilities of monetary reward. An Emotional Attentional Blink revealed preferential attention for HR over LR regardless of CA; while pleasantness ratings were unaffected, probably due to the intrinsic nature of CS. Experiment 2 (n = 60) replicated the effect of conditioning on the Emotional Attentional Blink utilising abstract CS (octagons/squares). In addition increased pleasantness for HR over LR was found significant overall, and marginally significant for Aware but not for Unaware participants. Here CA was rigorously determined using a signal-detection analysis and metacognitive-awareness measurements. Bayesian analyses verified the unconscious nature of the learning. These findings demonstrate that attentional conditioned responses can occur without CA and advance our understanding of the mechanisms by which implicit conditioning can occur and becomes observable. Furthermore, these results can highlight how addictive behaviours might develop.

Knowledge about the predictive value of reward conditioned stimuli modulates their interference with cognitive processes

“…Results of the flanker task are in line with data recently obtained by our group (Leganes-Fonteneau et al 2018) and by others (i.e., Bourgeois et al 2016) demonstrating the ability of reward CS to grab preferential attention implicitly. This interference is also congruent with previous examples of reward conditioning effects on a flanker task (Anderson et al 2012(Anderson et al , 2016a.…”

“…To help clarify this matter we investigated whether CS in the absence of CA can generate task-irrelevant interferences in cognitive control. As in previous research high reward (HR) CS generated preferential attentional responses in Unaware participants (Leganes-Fonteneau et al 2018), we expect here to replicate those findings and that HR stimuli will interfere with inhibitory control to a greater extent than low reward (LR), again in the absence of CA. This would allow us to draw a parallel between the ability of implicitly CS to affect executive control (Anderson 2016) and the interference of drug cues on inhibitory mechanisms (Wiers and Stacy 2006).…”

“…Most experiments have investigated this matter using stimuli explicitly associated with a substance (e.g., alcohol bottles or cigarettes) for which the stimulus-outcome contingency is clearly defined due to their own nature, thus impeding an accurate exploration of implicit components of drug addiction. Even though the procedures themselves, based on task-irrelevant distractor effects, are thought to be implicit, the explicit attributes of drug-related stimuli generated through prior consumption experiences (Wiers et al 2002) may affect task outcomes (Leganes-Fonteneau et al 2018). Stimuli conditioned with nondrug rewards can generate value-driven responses equivalent to those of drug-related stimuli (Anderson et al 2011), both attentional (Hogarth et al 2006a;Jeffs and Duka 2017) and emotional (i.e., Austin and Duka 2010).…”

“…In a recent series of experiments, in which CA was carefully measured using a novel Bayesian approach (Dienes 2015;Sand and Nilsson 2016), we found that targets, paired with increased probabilities of monetary reward, gathered preferential attention in an Emotional Attentional Blink task (Leganes-Fonteneau et al 2018). Importantly, this was observed in participants Unaware of stimulus-reward contingencies.…”

“…Using task-irrelevant procedures, it is possible to direct the focus of attention away from the stimulus-reward outcome, and in this way, delay explicit learning of stimulus-reward associations. We measured CA and metacognitive knowledge about contingencies on a trial-by-trial basis (Leganes-Fonteneau et al 2018) to determine the explicit knowledge about outcome contingencies gained by participants. Using a Bayesian analysis for this purpose, we were able to gather sensitive evidence for the existence of nonconscious learning.…”