Purchase this article with an account.
Liang Ming, Gao Meng, Fu Hualing, Li Zhaoping; Weaker interference from non-targets, rather than novelty, makes a reversed letter easier to find in visual search. Journal of Vision 2012;12(9):743. doi: 10.1167/12.9.743.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
It is easier to find a mirror reversed letter among its normal letter counterparts than vice versa. This is called the reversed letter effect. Traditionally, this has been explained by considering novelty, associated with a reversed letter, as a salient feature in visual search. Recently, using letter N and its mirror and/or rotated images as items in visual search stimuli, Zhaoping and Frith (2011) showed that the reversed letter effect is due to a task interference. This interference arises when mirror images of the target are present among non-targets, causing observers to confuse the target with these non-targets since shape recognition is typically viewpoint invariant. This interference is often manifested in a prolonged duration between the time when the gaze first located the target and the time when the search task decision is reached, occasionally causing gaze to abandon the target to search elsewhere. The interference should occur more quickly when searching for a more familiar target, since a familiar viewpoint speeds up shape recognition, thereby generating the reversed letter effect. We tested this further using eye tracking on general search stimuli, controlling whether any non-targets were mirror images of the target. No significant search asymmetry between reversed and normal letters was found when mirror images of the target were absent. This suggests that a reversed letter is not more salient. Furthermore, reaction times to find the target increased when its mirror images were among the non-targets, less so when the target was a reversed than a normal letter. Hence, a reversed letter target induces a weaker interference, rather than reducing reaction time by its novelty. The interference by mirror image non-targets was present even in observers with insignificant reversed letter effect, and even when some non-targets were not reversed letters for a normal letter target and vice versa.
Meeting abstract presented at VSS 2012
This PDF is available to Subscribers Only