Abstract
Sudden visual onsets appearing in the visual space grab attention – and the eyes – automatically, giving rise to oculomotor capture. Recently we demonstrated that the oculomotor capture associated with irrelevant visual onsets was significantly affected by the Suppression History acquired by their spatial location, so that it became easier to ignore onsets shown at locations where they had appeared more frequently. Whether this benefit in performance is transient, specifically supporting the online processing of visual stimuli, or whether it can give rise to lasting changes in performance is yet to be explored. To address this question, we carried out two experiments in which participants had to discriminate a visual target while ignoring an onset distractor (present in 64% of trials), while both manual responses and spontaneous saccades were recorded. Each Experiment comprised a Baseline, in which distractors could appear with the same probability across locations, and a Training, in which they appeared with higher frequency at two of the six possible locations (HF, 76% of distractor present trials). Finally, participants performed a Test, where location biases were removed. In two groups of different subjects this session took place either immediately after Training (Experiment 1) or 24-hours later (Experiment 2), to investigate any short or long-term impact of the frequency imbalances applied during Training. In line with previous reports, Suppression History markedly modulated attentional and oculomotor performance during the Training, reducing the impact of distractors appearing at HF locations. Strikingly, however, no trace of these filtering benefits has been found in either Test phase. While confirming that distractor filtering is more efficient at locations with a significant Suppression History, these data suggest that the benefit observed are due to ongoing adjustments of spatial priority that affect the immediate deployment of attentional resources, rather than to lasting learning-induced plasticity.
Acknowledgement: Grant “Ricerca di Base 2015” n.B32F15000670001