Automatic inhibition and habitual control: alternative views in neuroscience research on response inhibition and inhibitory control

Decades of theory and experimental evidence underscore the critical importance of inhibitory functions to flexible, contextappropriate and goal-directed action (Diamond et al., 1963; Logan and Cowan, 1984; Aron et al., 2004; Friedman and Miyake, 2004; Ridderinkhof et al., 2004; Munakata et al., 2011). Deficits in inhibitory control and response inhibition have been implicated in substance use disorders, attention-deficit/hyperactivity disorder, and impulse control disorders (Jentsch and Taylor, 1999; Nigg, 2001; Li and Sinha, 2008; Groman et al., 2009), and may also play a role in depression and anxiety (Disner et al., 2011; Jovanovic and Norrholm, 2011). But despite exciting progress in this area of cognitive and clinical neuroscience, some fundamental questions remain unsolved, and may be hindering the translational efforts aiming at improving the treatment and prevention of disorders characterized by impairment or dysregulation of inhibitory functions. The purpose of this Opinion is to highlight some alternative ideas and approaches in neuroscience research on response inhibition and inhibitory control that have emerged in the literature, in order to stimulate debate and suggest hypotheses for future research. In particular, building on recent neuroscience-based accounts of response inhibition (e.g., Mostofsky and Simmonds, 2008; van Gaal et al., 2008; Munakata et al., 2011), I argue against the long-standing and pervasive view that there is a fundamental distinction between inhibitory processes on the one hand and response selection and execution processes on the other hand. Although intuitive, this view does not appear to be supported by evidence. Instead, until there is evidence to the contrary, I propose a more parsimonious view of inhibitory control mechanisms in the brain, such that: (1) response inhibition can be either a control process (to override a prepotent response tendency) or it can itself be a prepotent response tendency (to be overridden); (2) response inhibition processes and response selection and execution processes are fundamentally the same; and (3) we learn to inhibit a response in fundamentally the same way that we learn to select and execute a response.