Ready, Set, Stop: The Role of Inhibitory Context in Unconscious Response Inhibition

Response inhibition is a key cognitive control process vital for flexibly responding to one’s environment. Indeed, impairments in this operation characterise many psychiatric and neurological disorders. Until recently, suppressing a response was thought to be a conscious process, however, research by van Gaal et al. (2008; 2010) demonstrates that unconscious no-go primes can trigger response inhibition, evidenced by a slowing in reaction time relative to unconscious go primes. This slowing is thought to be dependent on an inhibitory context being present i.e., occasional conscious stopping on a subset of trials (Chiu & Aron, 2014). The current study aimed to explore the role of inhibitory context in unconscious response inhibition. Participants responded as quickly and as accurately as possible to a mask depending on the prime (go or no-go) preceding it. Primes were either strongly (unconscious) or weakly (conscious) masked (presented for 16.7 ms or presented for 233 ms). Blocks of the task either had an inhibitory context (stopping required for weakly masked no-go trials) or a non-inhibitory context consisting only of strongly masked trials. In additional experiments, a generalised inhibitory context was introduced in place of the non-inhibitory context, requiring participants to inhibit their response to a conscious stimulus unrelated to the no-go prime. Unconscious response inhibition was observed both when the inhibitory context was task-specific or task-general. The results indicate unconscious response inhibition can be elicited within a generalised inhibitory context, suggesting the brain’s inhibitory network can be activated by general stopping behaviour