Metacognitive deficits are associated with lower sensitivity to preference reversals in nicotine dependence

Abstract

Deficits in impulse control belong to the core profile of nicotine dependence. Smokers might thus benefit from voluntarily self-restricting their access to the immediate temptation of nicotine products (precommitment) in order to avoid impulse control failures. However, little is known about how smokers' willingness to engage in voluntary self-restrictions is determined by metacognitive insight into their general preferences for immediate over delayed rewards. Here, with a series of monetary intertemporal choice tasks, we provide empirical evidence for reduced metacognitive accuracy in smokers relative to non-smokers and show that smokers overestimate the subjective value of delayed rewards relative to their revealed preferences. In line with the metacognitive deficits, smokers were also less sensitive to the risk of preference reversals when deciding whether or not to restrict their access to short-term financial rewards. Taken together, the current findings suggest that deficits not only in impulse control but also in metacognition may hamper smokers' resistance to immediate rewards and capacity to pursue long-term goals.

Figure 1

(A) In the confidence accuracy task, participants made choices between smaller-sooner (SS; e.g., 3 euro today) and larger-later (LL; e.g., 5 euro in 90 days) rewards. After each choice, they had to rate their subjective confidence to have made the best possible choice. (B) Consistent with previous findings, smokers discounted future rewards steeper than non-smokers. (C) Smokers also showed lower metacognitive accuracy than non-smokers, as indicated by a smaller difference between the slopes (which capture decision uncertainty) for low versus high confidence. For illustration purpose, we split confidence ratings into low versus high confidence trials. Shaded areas indicate 95% confidence intervals.

Figure 2

(A) In the bidding task, participants indicated which immediate reward magnitude they consider as equivalent to a given reward delivered in the future on a rating scale from 0 to 5 euro. The difference between subjective reward values estimated from observed choices in the confidence accuracy task (via individual hyperbolic discount parameters) and the self-reported values from the bidding task reflects the degree to which individuals over- or underestimate the value of future rewards relative to their revealed preferences. (B) Smokers, relative to non-smokers, overestimate their preferences for delayed over future rewards, particularly for longer delays, as indicated by higher self-reported than observed subjective values. Black dots indicate individual data points.

Figure 3

(A) In the precommitment task, participants opted between making a binding choice for a larger-later reward (e.g., 5 euro in 68 days) or postponing the decision. In the latter case, participants were re-contacted after 28 days and had to make a final choice between the adjusted reward options (in this example, “3 euro today versus 5 euro in 40 days”). (B) While non-smokers more strongly preferred to make a binding choice with increasing risk of preference reversals (i.e., the preference switches from the larger-later to the smaller-sooner option when being re-contacted after 28 days), smokers’ precommitment choices were unaffected by potential preference reversals. (C) The sensitivity to preference reversals correlated with individual differences in value bias, i.e. the degree to which individuals overestimate their preference for delayed over immediate rewards. Shaded areas in (B) indicate 95% confidence intervals.