Examining the Impact of Working Memory Training and Transcranial Direct-current Stimulation on Monitoring for Color Targets in Dynamic Visual Displays

Abstract

Previous research has demonstrated that when monitoring dynamically changing visual displays for color targets, contingencies between targets and distractors facilitate predictive target detection, and elevated intolerance of uncertainty (IU) and lower verbal working memory capacity (WMC) are associated with a higher false alarm rate (see Muhl-Richardson et al., 2018). The present study examined whether search in this type of task improved following placebo-controlled adaptive dual n-back working memory (WM) training or transcranial direct-current stimulation (tDCS) of the dorsolateral prefrontal cortex. It also attempted to replicate previous findings but at a high level of target prevalence. The results demonstrate a new benefit to predictive target detection, which was associated with faster response times, and identify elevated IU and verbal WMC were as significant predictors of a higher hit rate. We provide an account of these effects in terms of response criterion and perceptual sensitivity. WM training and tDCS were found not to benefit performance on our dynamic search task (and a range other cognitive tasks), adding to a mixed literature on the efficacy of these techniques. The results nonetheless extend our understanding of dynamic search tasks and have implications for the selection of personnel in a variety of real-world scenarios.