Ruminative thought is a characterizing feature of insomnia disorder. Despite its clinical relevance, research on the underlying cognitive mechanisms of rumination remains scarce. According to the processing efficiency hypothesis rumination interferes with normal cognition by taking up valuable working memory resources. Consequently, individuals with a tendency to ruminate will have to engage more effort to maintain effective task performance at the expense of cognitive efficiency. In the present study, we specifically investigated whether rumination was associated with a reduced cognitive control ability. In order to do this, we administered the continuous performance task (AX-CPT) to a group of undergraduates (n = 83). From this sample, low-ruminators (n = 25), moderate ruminators (n = 23) and high-ruminators (n = 23) were selected. In the AX-CPT task, subjects have to provide a certain response to target trials (i.e., AX) and a different response to non-target trials (i.e., BX, AY and BY), while target trials are presented with a high frequency (70%) and therefore creating an expectancy bias. The main results showed that although the three groups made a similar amount of errors on the task, high-ruminators were significantly slower than moderate- and low-ruminators on target trials. Furthermore, a significant interaction was found between the type of non-target trial and ruminator group, showing that moderate ruminators made more errors on AY trials compared to high ruminators, which indicated that moderate ruminators make use of a proactive strategy. Additionally, rumination was found to be significantly associated with poor subjective sleep quality and prolonged subjective sleep onset latency. The results lend further support that, given an equal performance between groups (similar error rates), rumination is associated with reduced efficiency in cognitive control (increased reaction time). Furthermore, these findings suggest that rumination is important for understanding sleep disturbances. In a follow-up study, we will examine whether this impairment in processing efficiency associated with a tendency to ruminate, also holds true in patients with insomnia disorder. Investigating the potential contribution of rumination to cognitive efficiency in patients with insomnia disorder may possibly elucidate reported difficulties in cognitive functioning in these patients.
|Title of host publication||The ULB-VUB Joint PhD Day in Psychology and Educational Sciences, November 5, Brussels (Belgium)|
|Publication status||Published - 5 Nov 2015|
|Event||ULB-VUB Joint PhD Day in Psychology and Educational Sciences - vub, brussels, Belgium|
Duration: 5 Nov 2015 → 5 Nov 2015
|Conference||ULB-VUB Joint PhD Day in Psychology and Educational Sciences|
|Period||5/11/15 → 5/11/15|