The role of the basal ganglia in habit formation

Abstract

Many organisms, especially humans, are characterized by their capacity for intentional, goal-directed actions. However, similar behaviours often proceed automatically, as habitual responses to antecedent stimuli. How are goal-directed actions transformed into habitual responses? Recent work combining modern behavioural assays and neurobiological analysis of the basal ganglia has begun to yield insights into the neural basis of habit formation.

Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings

“…Although the terms ‘reinforcement,’ and ‘reward’ are often used interchangeably, these terms have discrete behavioral definitions, and describe largely distinct neurobiological processes. Indeed, there are multiple constructs mediated by the mesolimbic system, and at least four such systems have been described in depth in numerous seminal reviews [39-43]: 1) reward motivation, also termed anticipation (typically subsuming what is colloquially described as ‘wanting,’) refers to processes that facilitate anticipation of reward and approach behaviors towards biologically relevant goals, including reward valuation, willingness to expend effort to obtain rewards, reward prediction, and reward-based decision-making [44]; 2) reward outcome (or the hedonic responses widely referred to as ‘liking’ or ‘pleasure’) includes both consummatory behaviors during reward obtainment and the processes associated with regulation of such behaviors [45]; 3) reward learning includes reward processes that shape the experience-dependent learning that guides future behaviors [46]; and 4) reward-related habitual behavior reflects those processes that are initiated based on reward feedback, but that persist even in the absence of such feedback [47,48]. …”

Adenosine Signaling in Striatal Circuits and Alcohol Use Disorders

“…Recently, an essential role of the dorsal striatum in the development of habitual seeking behaviors, which include the regulation of voluntary movement, acquisition of goal-directed actions, and stimulus-driven habits, has been revealed (Lovinger, 2010;Yin and Knowlton, 2006). Recent studies have investigated the contribution of adenosine signaling in sub-regions of the dorsal striatum, the dorsomedial striatum (DMS; equivalent to caudate nucleus) and the dorsolateral striatum (DLS; equivalent to putamen) to habitual-seeking behaviors.…”

“…While the ventral striatum (also known as the nucleus accumbens; NAc) mediates the rewarding and motivational effects of a substance or stimulus, the dorsal striatum (also known as the caudate-putamen; CPu) regulates voluntary movement and habitual behaviors (Everitt and Robbins, 2013;Voorn et al, 2004). Recent studies demonstrate that two different dorsal striatum regions, the dorsomedial striatum (DMS) and dorsolateral striatum (DLS), play distinctive roles in behavior development (Yin and Knowlton, 2006;Yin et al, 2007;. Notably, the DMS primarily regulates goal directed (action-outcome) behavior, which is sensitive to outcome devaluation and instrumental learning, whereas the DLS is involved in habit formation (stimulus-response) Graybiel, 2008;Yin et al, 2004).…”

“…The DMS (analogous to the caudate) is a part of the associative network, which is involved in 'working memory' and the anticipation of reward. By contrast, the DLS (similar to the putamen) receives input from the sensorimotor cortex and is involved in locomotor behavior and habit formation (Lovinger, 2010;Yin and Knowlton, 2006). Surprisingly, direct evidence for a role of striatal signaling in the behavioral shift from excessive ethanol drinking to habit development has not yet been established.…”

Are nonclinical obsessive-compulsive symptoms associated with bias toward habits?

“…These circuits have a significant overlap with two interacting brain systems thought to control instrumental behavior: a goal-directed system that encodes action-outcome associations (prefrontal cortex/dorsomedial striatum), and a habit system that encodes stimulus-response associations (dorsolateral striatum) (for a review see Yin and Knowlton (2006)). According to the habit hypothesis of OCD (Graybiel and Rauch, 2000;McDonald et al, 2004;Robbins et al, 2012), compulsive symptoms are caused by deficits in goal-directed learning, which lead to excessive reliance on stimulus-response habits.…”