Humans and other animals learn which stimuli and actions predict positive outcomes or rewards, such as food, mates, or drugs. These reward and reinforcement learning mechanisms are complex, consisting of several psychological processes, such as hedonic responses to rewards, motivational processes, and the formation of associations between reward stimuli (cues) and actions with rewards (i.e., learning).
The mechanisms of reward and reinforcement learning are not fully understood at the neural level as they involve multiple brain systems. The mesolimbocortical and nigrostriatal dopamine circuits are the most notable among these systems and it is our desire to better understand them. Specifically, our goal is to discover how reward and reinforcement learning neural systems are changed following early-life adversity, exposure to natural rewards, and drugs of abuse.
We also desire to uncover how decisions are made in conflicting motivational states. We want to know how these conflicts are ‘resolved’ at neural and behavioural levels.
Our discovery pursuits bisect basic science, preclinical models of diseases, and translational research approaches.
From Early-Life Adversity to Addiction – Behaviour, Neural Circuits, and Treatments
The costs of addiction on personal, societal, and economic levels are enormous. Addiction is a complex disorder characterized by numerous cognitive-behavioral hallmarks, but the most prominent feature of addiction is sensitized motivation for drug consumption. While the vast majority of individuals sample potentially addictive substances (e.g., alcohol, nicotine, etc.), only a minority become addicted to drugs. We still do not know why some individuals get addicted to drugs while others do not. Several studies have suggested a link between early-life adversity, such as abuse and neglect, and addiction prevalence. This link is based on retrospective and correlational studies and reliable causal links between early-life adversity and addiction remain elusive. We are interested in examining the relationship between early-life adversity and addiction in experimental, preclinical models of addiction. These studies vary in focus, from molecules to behaviour.
Here are some questions we desire to answer:
- How does early-life adversity alter neural responses to drugs of abuse, such as cocaine, nicotine, or oxycodone?
- How does early-life adversity alter patterns of drug self-administration?
- How can we, behaviorally or pharmacologically, best prevent and treat addiction?
Decision-Making Processes in the Context of Learning and Motivational Conflicts
Mammals and other organisms learn through several processes, such as habituation, sensitization, classical (Pavlovian) conditioning, instrumental or operant learning. These learning processes interact and often facilitate each other. For example, in the Pavlovian-to-Instrumental transfer, an appetitive Pavlovian cue (e.g., sound of the bell previously paired with food) can facilitate or energize (instrumental) actions for food. However, in real life, goal-directed (action-outcome) behaviour can be in conflict with Pavlovian stimuli. That is, individuals can be motivated to make instrumental responses for rewards but be presented with appetitive Pavlovian stimuli that might draw them away from their goals. We seek to investigate behavioural parameters and outcomes of decision making processes in learning and motivational conflict situations. Furthermore, we desire to understand the neural dynamics of decision making in conflict situations.
Here are a few questions we desire to answer:
- What are the mesolimbic and nigrostriatal dopamine dynamics in conflict decision making situations?
- How can we behaviourally or pharmacologically improve decision making processes in Pavlovian-Instrumental conflict states?