An investigation of rumination constructs at different levels of cognitive load

Abstract

Four studies investigated the relationships between executive functioning performance under different types of cognitive load (intrinsic and extraneous), and operationalisations of rumination (brooding, reflection and content-independent), while also exploring whether self-regulatory depletion and working memory training can play a role in influencing these relationships. To first determine whether different types of cognitive load correspond to different kinds of rumination, Study 1 experimentally manipulated load using negative priming and modified continuous performance tasks while examining mood, self-reported rumination, and task-related thoughts over a three-week period. Findings for the continuous performance tasks suggested specific forms of rumination may predict performance under specific forms of load, but this was qualified by the very strong impact of the extraneous load manipulation, limited temporal resolution of the content-independent rumination questionnaires, and the extent of element interactivity in the intrinsic load manipulation. This posed three further questions, addressed by the ensuing studies.

Study 2 assessed whether a weaker extraneous load manipulation would yield different results by administering a revised form of the continuous performance task manipulation. Results suggested that while rumination continued to correlate with and predict constructs in ways similar to before, to some extent it positively correlated with better performance at this reduced level of extraneous load.

Study 3 investigated whether a task with higher element interactivity than the modified continuous performance task would yield different results for intrinsic load relative to Study 1, and also explored the possibility that self-regulatory depletion may be an overlooked process in the relationship between rumination and executive performance. We administered a Stroop task that manipulated intrinsic load by adding conflictual response rules, creating more interactivity between task elements, and manipulated self-regulatory depletion using the classic e-crossing task. Again, results suggested that rumination positively correlated with some indicators of better executive function performance, but also some other indices of reduced performance on the task, as well as expected variables such as low mood. Results did not support a significant effect of self-regulatory depletion on the other variables of interest.

Study 4 explored if working memory training tasks may be used to bolster performance under extraneous load from a rumination induction. Participants completed a very brief working memory training paradigm based on reading span tasks. Operation span tasks were administered before and after to measure executive function performance. The latter operation span was preceded by a rumination induction. While there was evidence that the training paradigm was somewhat effective in improving operation span performance, the rumination inductions resulted in limited effects, which may have been due to the impact of the cognitive tasks upon mood.

Broadly, thesis results suggested a nuanced relationship between rumination and level of cognitive load, and bore out the position that information processing theories of rumination may benefit from distinguishing intrinsic and extraneous loads when manipulating them. They also indicated that rumination measures should continue to include content-dependent and independent forms, but efforts to explore timecourse of self-reported rumination and self-regulatory depletion contributed little to our results. Findings were limited by the use of generally unemotive stimuli on behavioural tasks, sampling constraints, multiple comparisons and paradigm limitations. Overall, this thesis supports greater consideration of cognitive load type in future information processing studies of rumination. Show more