No training effects of top-down controlled response inhibition by practicing on the stop-signal task.

The aim of the current study is to examine if the top-down controlled response inhibition on a stop-signal task (SST) can be trained. Results from previous studies have been equivocal, possibly because signal-response combinations are often not varied across training and test phases, allowing bottom-up signal-response associations to be formed that may improve response inhibition. The current study compared the response inhibition on the SST in a pre-test and post-test in an experimental group (EG) and control group (CG). In between tests, the EG received ten training sessions on the SST with varying signal-response combinations that were also different from the combinations in the test phase. The CG received ten training sessions on the choice reaction time task. Results failed to reveal a decrease in stop-signal reaction time (SSRT) during and after training, with Bayesian analyses revealing anecdotal and substantial evidence for the null hypothesis during and after training, respectively. Yet, the EG did show smaller go reaction times (Go_RT) and stop signal delays (SSD) after training. The results indicate that the top-down controlled response inhibition is difficult or impossible to improve.