Introduction
Alcohol addiction is one of the biggest problems of modern society
through its impact on health, social cohesion, crime, and its
comorbidity with other neuropsychiatric disorders. Major advances in
genetics and molecular neurobiology have led to the identification of
many of the primary targets of alcohol and revealed neuroadaptations
that develop with its chronic consumption. However, understanding
pre-existing cognitive deficits that serve as substrates compounding the
initiation of alcohol use and the development of alcohol use disorder
(AUD) remains a major challenge.
All goal-directed behaviours, including alcohol use and abuse, are
composed of two core components: the decision-making process, which
starts with representations of the available options that lead to the
selection of the option with the highest expected value, and
reinforcement learning, through which outcomes are used to refine value
expectations. The decisions based on the above-mentioned processes are
often biased by an abnormal sensitivity to positive and negative
reinforcement, which results in abnormal sensitivity to performance
feedback, skewed interpretations of ambiguity, inflated expectations,
and asymmetrical belief updating. We have defined this abnormal
cognitive processing as reinforcement-based cognitive biases (RBCBs).
While the investigation of cognitive biases has a long history in
economics and psychology, RBCBs in the context of AUD have been much
less systematically investigated and, perhaps, neglected. This is
surprising, as most of the decisions regarding alcohol-related
behaviours are related to their positive and negative reinforcing
effects. Although the causal role of the RBCBs in AUD has been
emphasized by various psychological theories and investigating the
interrelations between biased cognition and AUD could become a thriving
area of research that capitalizes on the newest advances in cognitive
neuroscience, psychology, and psychiatry, studying the nature and the
extent to which RBCBs play a role in the development and maintenance of
alcohol addiction still faces formidable methodological obstacles and
does not provide definite answers regarding underlying mechanisms.
In this review, we first briefly describe psychological and cognitive
theories that implicated various aspects of reinforcement-biased
cognition in the development, maintenance, and recurrence of alcohol
addiction. Furthermore, in separate sections, we describe recent studies
investigating the RBCBs, their neural, neurochemical, and
pharmacological correlates, and possible interactions between RBCBs and
trajectories of AUD. Finally, we describe how recent translational
studies using state-of-the-art animal models could facilitate our
understanding of the role of reinforcement sensitivity and RBCBs in
various aspects of AUD.