The influence of literacy on visual search
Olivers, C. N. L., Huettig, F., Singh, J. P., & Mishra, R. K.
The influence of literacy on visual search. Visual Cognition, 21
, 74-101. doi:10.1080/13506285.2013.875498.
Currently one in five adults is still unable to read despite a rapidly developing world. Here we show that (il)literacy has important consequences for the cognitive ability of selecting relevant information from a visual display of non-linguistic material. In two experiments we compared low to high literacy observers on both an easy and a more difficult visual search task involving different types of chicken. Low literates were consistently slower (as indicated by overall RTs) in both experiments. More detailed analyses, including eye movement measures, suggest that the slowing is partly due to display wide (i.e. parallel) sensory processing but mainly due to post-selection processes, as low literates needed more time between fixating the target and generating a manual response. Furthermore, high and low literacy groups differed in the way search performance was distributed across the visual field. High literates performed relatively better when the target was presented in central regions, especially on the right. At the same time, high literacy was also associated with a more general bias towards the top and the left, especially in the more difficult search. We conclude that learning to read results in an extension of the functional visual field from the fovea to parafoveal areas, combined with some asymmetry in scan pattern influenced by the reading direction, both of which also influence other (e.g. non-linguistic) tasks such as visual search.