Functional Neuroimaging of Avoidance Habits in Obsessive-Compulsive Disorder

“We used the PickAtlas software toolbox in SPM8 (36) to define regions of interest according to the Anatomical Automatic Labeling atlas.”

“The present study aimed to test for neurobiological convergence in support of this possibility, drawing on a rich cross-species neuroscience literature, which has identified dissociable neural substrates of these two systems (9).”

“Another region in the basal ganglia, the putamen, is necessary for the formation of stimulus-response habits with practice (11, 15, 16).”

“Habits are automatic stimulus-driven behaviors that can arise under many conditions, the most commonly accepted of which is the overtraining of simple responses (2).”

“However, habits can also arise from failures in goal-directed control, which can render behavior habitual even very early on in training (3, 4).”

“Hyperactivation in the caudate is one of the most consistent neurobiological markers of OCD symptoms (with medial orbitofrontal cortex hyperactivation being the other) (18, 19), and our data therefore lend strong support to a model of OCD centered on deficits in goal-directed control over actions, resulting in compuls…”

“Moreover, a similar dependency has been observed in healthy humans, such that the formation of habits is associated with white matter connectivity strength between the putamen and premotor cortex (11), as well as changes in putamen activity over time (16) (although directionality of the latter association has been inc…”

“The majority of our medicated patients were taking serotonergic medication (mainly SSRIs), which in previous work has been shown to affect avoidance responding and inhibition in healthy humans (50).”

“This conclusion dovetails with recent data showing that model-based instrumental learning, which is a constituent of goal-directed control, is impaired in OCD and reliant on the structural integrity of the medial orbitofrontal cortex and caudate but not the putamen (8).”

“Since this is the first study, to our knowledge, to examine the neural correlates of avoidance habits, whether these results can be generalized to appetitive habit forming, which is similarly overactive in OCD (5), is an open question.”

“(45), as well as with findings from studies suggesting that stress and anxiety contribute to habit biases in healthy people (48, 49), it is likely that a complex interaction between fear learning and habits may be critical to understanding the pathogenesis of OCD.”

“Moreover, a similar dependency has been observed in healthy humans, such that the formation of habits is associated with white matter connectivity strength between the putamen and premotor cortex (11), as well as changes in putamen activity over time (16) (although directionality of the latter association has been inc…”

“, contingency learning [10, 38, 39]).”

“Hyperactivation in the caudate is one of the most consistent neurobiological markers of OCD symptoms (with medial orbitofrontal cortex hyperactivation being the other) (18, 19), and our data therefore lend strong support to a model of OCD centered on deficits in goal-directed control over actions, resulting in compuls…”

“(45), as well as with findings from studies suggesting that stress and anxiety contribute to habit biases in healthy people (48, 49), it is likely that a complex interaction between fear learning and habits may be critical to understanding the pathogenesis of OCD.”

“Moreover, a similar dependency has been observed in healthy humans, such that the formation of habits is associated with white matter connectivity strength between the putamen and premotor cortex (11), as well as changes in putamen activity over time (16) (although directionality of the latter association has been inc…”

“Supporting Data Explicit contingency knowledgewas equivalent across groups (F,1) (6).”

“Another region in the basal ganglia, the putamen, is necessary for the formation of stimulus-response habits with practice (11, 15, 16).”

“The habit hypothesis of obsessive-compulsive disorder (OCD) suggests that the disorder reflects dysfunction in the brain systems that support automatic habits and more purposeful, goal-directed control over action (1).”

“The role of the subgenual anterior cingulate cortex in habit forming has been sparsely studied, but two studies have shown that its likely homolog, the infralimbic cortex, must be intact for habits to persist in rodents (40, 41), suggesting that excessive connectivity between this region and the caudate may be one pos…”

“The role of the subgenual anterior cingulate cortex in habit forming has been sparsely studied, but two studies have shown that its likely homolog, the infralimbic cortex, must be intact for habits to persist in rodents (40, 41), suggesting that excessive connectivity between this region and the caudate may be one pos…”

“(45), as well as with findings from studies suggesting that stress and anxiety contribute to habit biases in healthy people (48, 49), it is likely that a complex interaction between fear learning and habits may be critical to understanding the pathogenesis of OCD.”

“Although less consistently implicated, there is some suggestion that the putamen may be enlarged in OCD, an effect related to age and plausibly the chronic performance of compulsive behavior (33).”

“Based on previous literature on habit learning in healthy humans and the known neurobiological profile of OCD, we examined anatomically defined bilateral a priori regions of interest: the medial orbitofrontal cortex (11–13), the caudate (10, 11), and the putamen (11, 16).”

“Cocaineinduced habitual responding is associated with increased excitability in the rodent homolog of the caudate (37), and in humans, white matter connectivity between the caudate and the medial orbitofrontal cortex is predictive of improved goal-directed control over action (11) on a task that reveals habit biases i…”

“, contingency learning [10, 38, 39]).”

“This could reflect overgeneralization of fear, which has been shown to relate to maladaptive instrumental avoidance (47).”

“Moreover, a similar dependency has been observed in healthy humans, such that the formation of habits is associated with white matter connectivity strength between the putamen and premotor cortex (11), as well as changes in putamen activity over time (16) (although directionality of the latter association has been inc…”

“However, two recent studies found deficits in goal-directed behavior during trial-by-trial learning in OCD, using paradigms that did not involve repeating simple responses (7, 8).”

“To test for habits, we used the “outcome devaluation” technique, in which behavior is defined as a habit if it persists despite changes in the value the action produces (34); in other words, habits are behaviors that are driven by stimuli, not by motivation or goals.”

“However, habits can also arise from failures in goal-directed control, which can render behavior habitual even very early on in training (3, 4).”

“…March 2016 Reviewing editor: Michael J Frank, Brown University, United States Copyright Gillan et al. This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited.”

“In a recent fMRI study on habit formation in OCD patients, Gillan et al. (2015) tested, using a shock avoidance paradigm, whether habits in OCD primarily arise from dysfunction in the goal-directed (ventral) or the habit (dorsal) system.”