Abstract
Pop out in visual search refers to quick and efficient identification of a target, e.g. a single, unique item among homogenous distractors. In false pop out (FPO, Orsten-Hooge, Portillo & Pomerantz, 2015), one of the homogenous distractors competes with the singleton target to pop out as it breaks a global pattern in the display. Behavioural responses have revealed FPO in both accuracy and RTs. Here, eye movements were used to further explore FPO. The task was always an odd-quadrant localization with three display types: FPO displays composed of negative and positive diagonal lines forming potential patterns being broken by one of the non-unique distractor lines; Line Control displays composed of horizontal and vertical lines forming no potential global pattern; and Letter Control displays composed of letter pairs (A/B, X/O) (Experiment 1; Orsten-Hooge et al., 2015). As predicted, FPO was found in both accuracy and RT measures with a 1000 ms display exposure duration (Experiment 1), but also with an unlimited display exposure duration (Experiment 2). Eye movements from Experiment 1 revealed participants made more fixations and had longer total fixation durations on FPO trials than on Line Control displays. Analysis of the eye movements from Experiment 2 showed participants made more fixations and fixation durations were longer during FPO display trials than with any Control display trial. During FPO display trials in Experiment 2, participants' attention was often drawn to the non-unique distractor item that broke the display's pattern. Importantly, this happened even when participants reported the unique item as being different. These results not only replicate initial findings regarding FPO (Orsten-Hooge et al., 2015), but also demonstrate the phenomenon via eye movements, lending strong support to the predication that FPO arises from competition between basic-feature and configural properties.
Meeting abstract presented at VSS 2016