Abstract
The Flanker task, well-known in Psychology, is thought to capture fundamental aspects of selective visual attention. Yet traditional presentations only consider static selectivity, ignoring the more ecologically valid question of dynamic selective visual attention. In the traditional Flanker task, participants respond to a central, directional, target flanked by distractors. Targets such as arrows (e.g., > or <) are in a central position, and are flanked by directional distractors in experimental conditions (e.g., >>>>> or <<><<) and by non-directional shapes in the control condition (e.g. **<**).Respondents are asked to indicate the direction of the target shape, and these responses are timed. The Flanker effect is the tendency to take longer to respond to incongruent flankers (e.g., <<><<) than to either congruent (e.g., >>>>>) or neutral (e.g., **<**) flankers. This task is traditionally presented with static, page-centered, stimuli. However, the static presentation allows visual hyper-focus on the target which limits interaction with distractors. To investigate the Flanker effect in a more ecologically valid scenario, we jittered Flanker stimuli horizontally. This jitter allows exploration of selective visual attention by requiring reacquisition of the target and concomitant engagement with flankers. In a within-groups block design, participants were presented with both centered and jittered stimuli conditions. We predicted that the Flanker effect would be greater in the jittered condition. A paired samples t-test found a significant difference in the scores for jittered stimuli (M = 160.17; SD = 104.71) and centered stimuli (M = 82.08; SD = 48.95); t(36) = 5.63, p < 0.001. This effect was large (d = 0.93 95% Cl [0.54, 1.31]). On average, the Flanker effect was twice as high in jittered stimuli compared to centered stimuli. The dynamic Flanker we present adds a new dimension to a classic task for considering selective visual attention.