The impact of saliency on overt visual selection in early-deaf adults

Benedetta Heimler, Wieske van Zoest, Francesca Baruffaldi, Pasquale Rinaldi, Maria Cristina Caselli, Francesco Pavani

Last modified: 2013-05-05

Abstract


Following bilateral deafness, vision reorganizes to overcome the lack of audition. Results from covert attention studies show enhanced reactivity and rapid attention orienting to abrupt visual stimuli in deaf people, suggesting that crossmodal changes may prioritize saliency-driven attention capture in this population. However, deaf individuals also need to maintain goal-directed behaviors. We investigated the time-course of overt visual selection in deaf adults, to assess when in time deaf individuals implement efficient top-down control over saliency-driven search. Eighteen early-deaf adults and sixteen hearing controls performed an oculomotor additional singleton paradigm. For deaf participants language abilities in oral and sign languages were assessed. Participants made a speeded saccadic eye movement to a unique orientation singleton. The target was presented among homogenous non-targets and one additional orientation singleton that was more, equally or less salient than the target. Results showed a similar pattern of performance in the two groups: fast initiated saccades were saliency-driven whereas later initiated saccades were more goal-driven. However, deaf were overall slower than hearing participants at initiating saccades. This delay in saccadic latencies was driven by a sub-group of deaf adults, who were able to bypass saliency capture by withholding their saccades until target selection was efficiently achieved. No correlation with linguistic abilities emerged, showing no role of sign language acquisition in this behavior. Taken together, the present findings reveal that overt visual reorganization in deaf adults does not drastically alter the interplay between bottom-up and top-down strategies. If anything, it prioritizes the implementation of efficient goal-directed behaviors.

Keywords


Deafness; eye-movements; visual selection

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