Abstract: Understanding the neurobiological mechanisms underlying inhibitory control is crucial given its role in various disease states and substance abuse/misuse. Neuroimaging research examining inhibitory control has yielded conflicting results on the relative importance of the left and right hemisphere during successful inhibition of a motor response. In the current study, a split-brain patient was examined in order to assess the independent inhibitory capabilities of each hemisphere. The patient's right hemisphere exhibited superior inhibitory ability compared to his left hemisphere on three inhibitory control tasks. Although inferior to the right, the left hemisphere inhibited motor responses on inhibitory trials in all three tasks. The results from this study support the dominance of the right hemisphere in inhibitory control.
Abstract: This chapter focuses on inhibitory control, largely operationalised as response inhibition, and its contribution to substance abuse, and highlights results from two classic tasks of response inhibition: the stop‐signal task, and the go/no‐go task. It discusses the relationship between response inhibition and substance abuse disorders as studied with functional neuroimaging and event‐related potentials, where response inhibition will be considered as a means to characterise the cognitive control deficits of substance‐dependent individuals. As the neural circuitry of response inhibition is relatively well understood and yields reliable and sensitive behavioural measures of inhibitory ability, it has generated a significant number of studies focused on the role of response inhibition in addiction. Neuroimaging research has identified the dorsolateral prefrontal cortex (dlPFC) as a brain region critical for cognitive control. Inhibitory control has been repeatedly implicated in drug addiction and may be especially relevant for treatment success.
Abstract: Historically, neuroscientific research into addiction has emphasized affective and reinforcement mechanisms as the essential elements underlying the pursuit of drugs, their abuse, and difficulties associated with abstinence. However, research over the last decade or so has shown that cognitive control systems, associated largely but not exclusively with the frontal lobes, are also important contributors to drug use behaviors. Here, we focus on inhibitory control and its contribution to both current use and abstinence. A body of evidence points to impaired inhibitory abilities across a range of drugs of abuse. Typically, studies suggest that substance-abusing individuals are characterized by relative hypoactivity in brain systems underlying inhibitory control. In contrast, abstinent users tend to show either normal or supernormal levels of activity in the same systems attesting to the importance of inhibitory control in suppressing the drug use urges that plague attempts at abstinence. In this chapter, the brain and behavioral basis of response inhibition will be reviewed, with a focus on neuroimaging studies of response inhibition in current and abstinent drug abusers.
Abstract: Loss of control over one's behavior is a defining characteristic of addiction. It is central to the diagnosis of a substance use disorder; it is characteristic of the all‐too‐common relapses of abstinent users who attempt to stay clean; and it is apparent when initial intentions to have just one drink escalate into a binge‐drinking session. One particular aspect of cognitive control that these examples allude to is inhibitory control: the ability to suppress or countermand a thought, action, or feeling. From this perspective, one can conceive of the failure to control drug‐related ruminations, the incapacity to avoid the route that takes one past one's regular bar, or the inability to suppress drug cravings as different instances of failed inhibitory control. Studying these real‐world examples of inhibitory control can be challenging in the lab, and especially in the constrained setting required for …