Salient distractors appearing in the visual field trigger an involuntary oculomotor capture, so being able to ignore them is paramount for an efficient attentional selection. Recent findings have revealed that past experience of distractor filtering greatly affects the deployment of attention such that it can reduce the priority of locations frequently associated with irrelevant information and, accordingly, weaken the interference of distractor appearing therein. Such benefit associated with suppression history suggests that selective attention has adaptive experience-dependent features. There are still gaps however in the knowledge of the mechanisms underlying these phenomena, that need to be more clearly identified and detailed. In a series of experiments, we addressed this topic by exploring the effect of suppression history on the immediate behavioral measures of attentional deployment - i.e. eye-movements - and on their neural correlates. Using variants of a visual search task, we manipulated the probability of occurrence of a salient distractor such that it occurred more frequently at two locations on the visual display, unbeknown to the participants (High Frequency locations - HF). The results showed that the amount of oculomotor capture triggered by the distractors appearing at HF locations was dramatically reduced relative to distractors appearing at other locations, consistently with the improvement also shown on task performance. Testing the permanence over time of these benefits, we found that some residual effects of suppression history were still detectable after the frequency unbalances were no longer in place, but their traces lingered for a very short time, vanishing definitively 24-hours later. Importantly, the bias induced by suppression history was accomplished by changes in neural activity at a relatively early stage of cortical visual processing. Indeed, the distractor-related cortical activities explored at posterior-occipital areas showed a reduced neural activation for distractors appearing at HF locations as indexed by a smaller N2pc, hence providing evidence of a decreased deployment of selective attention towards these stimuli, prior to saccadic planning. In summary, this work provides compelling evidence that suppression history affects attentional spatial priority by dynamically down-weighting the representation of spatial locations that have been more frequently associated with distraction, and whose selection has been therefore inhibited. Our data suggest that such plasticity, within topographic maps of the visual space, is transient and functional, and supported by neural changes in cortical visual processing that sustains ongoing oculomotor control.

Dealing with distractor interference: the impact of suppression history on attentional and oculomotor capture

Di Caro, Valeria
2020-01-01

Abstract

Salient distractors appearing in the visual field trigger an involuntary oculomotor capture, so being able to ignore them is paramount for an efficient attentional selection. Recent findings have revealed that past experience of distractor filtering greatly affects the deployment of attention such that it can reduce the priority of locations frequently associated with irrelevant information and, accordingly, weaken the interference of distractor appearing therein. Such benefit associated with suppression history suggests that selective attention has adaptive experience-dependent features. There are still gaps however in the knowledge of the mechanisms underlying these phenomena, that need to be more clearly identified and detailed. In a series of experiments, we addressed this topic by exploring the effect of suppression history on the immediate behavioral measures of attentional deployment - i.e. eye-movements - and on their neural correlates. Using variants of a visual search task, we manipulated the probability of occurrence of a salient distractor such that it occurred more frequently at two locations on the visual display, unbeknown to the participants (High Frequency locations - HF). The results showed that the amount of oculomotor capture triggered by the distractors appearing at HF locations was dramatically reduced relative to distractors appearing at other locations, consistently with the improvement also shown on task performance. Testing the permanence over time of these benefits, we found that some residual effects of suppression history were still detectable after the frequency unbalances were no longer in place, but their traces lingered for a very short time, vanishing definitively 24-hours later. Importantly, the bias induced by suppression history was accomplished by changes in neural activity at a relatively early stage of cortical visual processing. Indeed, the distractor-related cortical activities explored at posterior-occipital areas showed a reduced neural activation for distractors appearing at HF locations as indexed by a smaller N2pc, hence providing evidence of a decreased deployment of selective attention towards these stimuli, prior to saccadic planning. In summary, this work provides compelling evidence that suppression history affects attentional spatial priority by dynamically down-weighting the representation of spatial locations that have been more frequently associated with distraction, and whose selection has been therefore inhibited. Our data suggest that such plasticity, within topographic maps of the visual space, is transient and functional, and supported by neural changes in cortical visual processing that sustains ongoing oculomotor control.
2020
Visual selective attention, distractor filtering, oculomotor capture, eye-movements, suppression history, statistical learning, Event-related potentials (ERPs)
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/1016677
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