The influence of cognitive styles and strategies in the digit span backwards task: Effects on performance and neuronal activity

The way information is processed in the brain varies strongly between individuals. A prominent distinction is made between visual and verbal processing in everyday-life as well as concrete tasks at hand. To investigate the role of routinely-used cognitive styles and task-specific cognitive strategies, n = 40 participants were presented with the digit span backwards task - which is widely used as a measure of working memory capacity with acoustically or optically presented stimuli. In a dual task condition, the participants had to remember both an acoustically and an optically presented digit series. The task specific cognitive strategy was predictive for dual task performance, while the habitual cognitive style was not. Also, the preference for a verbal or visual cognitive style was not associated with the task specific strategy, indicating that a visual or verbal strategy can be adapted deliberately in order to perform the task at hand. Functional magnetic resonance imaging showed that a verbal processing style is associated with higher activation in the middle frontal gyrus, which is crucial for working memory performance. The results indicate that a verbal processing style is associated with more effort, possibly due to the adaptation of a task-specific strategy. (C) 2015 Elsevier Ltd. All rights reserved.