Generalizability of carry-over effects in the emotional Stroop task

The emotional Stroop task has been the most widely used task to examine attentional bias to emotionally salient stimuli. In one format of this task, words are presented to participants in a mixed randomized or quasi-randomized sequence. Using a mixed smoking Stroop task, we have previously demonstrated that smokers are slower to respond to words which follow smoking-related words than words which follow neutral words. Here we show that this carry-over effect is present in heroin addicts-but not control subjects-in a heroin Stroop task, and in normal subjects in a stress Stroop task. Thus, the effect generalizes to other populations. In addition, an examination of the studies that have collected data from both mixed and blocked formats provides converging evidence for the presence of carry-over effects. We discuss the implications of the carry-over effect for research using the emotional Stroop task.     

Carry-over effect between diet and physical activity: the bottom-up and top-down hypotheses of hierarchical self-efficacy

Healthy diet and physical activity have consistently been found to be positively correlated; however, most health behavior theories are focused on regulation of changes in single, rather than multiple, behaviors. Thus, this study explored the mechanism of the carry-over effect between diet and physical activity by conducting a longitudinal study with 706 participants to test the bottom-up and top-down hypotheses of hierarchical self-efficacy (SE). At Time 1 (baseline) and Time 3 (4 weeks after baseline), dietary behavior, physical activity, and self-efficacies of these behaviors (at the contextual level) were measured, while at Time 2 (2 weeks after baseline), general SE (at the general level) was assessed. Mediation analysis and structural equation models supported both the bottom-up and top-down hypotheses for different levels of self-efficacies, suggesting that hierarchical SE is an important factor underlying the carry-over mechanism between diet and physical activity.     

The transference of visual search between two unrelated tasks: Measuring the temporal characteristics of carry-over

Investigations into the persistence of top-down control settings do not accurately reflect the nature of dynamic tasks. They typically involve extended practice with an initial task, and this initial task usually shares similar stimuli with a second task. Recent work shows that visual attention and search can be affected by limited exposure to a preceding, unrelated task, and the current study explored the temporal characteristics of this “carry-over” effect. Thirty-four participants completed one, four, or eight simple letter searches and then searched a natural scene. The spatial layout of letters influenced spread of search in the pictures, and this was further impacted by the time spent in the initial task, yet the carry-over effect diminished quickly. The results have implications for theories of top-down control and models that attempt to predict search in natural scenes. They are also relevant to real-world tasks in which performance is closely related to visual attention and search.