Two lingering delays in a go/no-go task: mind wandering and caution/uncertainty slow down thought probe response times

In a go/no-go task, lengthening the inter-trial interval (ITI) or decreasing the press percentage (PP) are known to have decelerating effects on both reaction time and on thought probe response time. The mental causes of these delays remain obscure. We performed an 18-minute online experiment with 60 participants who each performed 8 versions of an attention task (Test of Variables of Attention, ToVA) with different ITIs and PPs. After each block there were mind wandering (MW) thought probes and rating scales for subjective effort and awareness. A version of the ToVA with zero no-go-stimuli spontaneously and implicitly accelerated mean reaction time significantly. That version also quickened three subsequent response times for rating tasks by hundreds of milliseconds, which suggests that the basis of this effect is a lingering mental state. None of the subjective ratings measured were strongly related to the reaction time delay, although MW seems to delay the thought probe response. We conclude that there may be another lingering state besides MW. To perform different tasks participants make mental speed-accuracy trade-offs whereby the participant adopts a lingering mental strategy that speeds up thinking by reducing caution/uncertainty, quickening both reaction times and thought probe response times.