In everyday life, involuntary thoughts about future plans and events occur as often as involuntary thoughts about the past.
However, compared to involuntary autobiographical memories (IAMs), such episodic involuntary future thoughts (IFTs)
have become a focus of study only recently. The aim of the present investigation was to examine why we are not constantly
flooded by IFTs and IAMs given that they are often triggered by incidental cues while performing undemanding activities. One possibility is that activated thoughts are suppressed by the inhibitory control mechanism, and therefore depleting
inhibitory control should enhance the frequency of both IFTs and IAMs. We report an experiment with a between-subjects
design, in which participants in the depleted inhibition condition performed a 60-min high-conflict Stroop task before
completing a laboratory vigilance task measuring the frequency of IFTs and IAMs. Participants in the intact inhibition
condition performed a version of the Stroop task that did not deplete inhibitory control. To control for physical and mental
fatigue resulting from performing the 60-min Stroop tasks in experimental conditions, participants in the control condition
completed only the vigilance task. Contrary to predictions, the number of IFTs and IAMs reported during the vigilance task,
using the probe-caught method, did not differ across conditions. However, manipulation checks showed that participants’
inhibitory resources were reduced in the depleted inhibition condition, and participants were more tired in the experimental
than in the control conditions. These initial findings suggest that neither inhibitory control nor physical and mental fatigue
affect the frequency of IFTs and IAMs