Early event-related potential (ERP) hemispheric asymmetries recorded at occipitoparietal sites are usually observed following the sudden onset of a lateral peripheral stimulus. This is usually reflected in an onset-locked larger N1 over the posterior contralateral hemisphere relative to the ipsilateral hemisphere, an early ERP asymmetry labeled N1pc. When the peripheral sudden onset is followed by a central stimulus, or by a bilaterally balanced visual array of stimuli, these events evoke a reversed N1pc, that is, a larger N1 over the hemisphere ipsilateral to the peripheral sudden onset. This N1pc reversal has been taken as evidence for a remapping of the visual space from an absolute, retinally based frame of reference to a relative, attentionally based frame of reference that codes the spatial positions of objects relative to the peripheral sudden onset, rather than relative to the fovea. Here, we pit the reference frame-remapping account against an alternative account based on reduced neural reactivity following the peripheral sudden onset. In three experiments, we varied the spatial location of an object relative to a preceding sudden onset, and tested the opposite predictions generated by the frame-remapping and the reduced neural reactivity accounts. Taken together, the results from the present experiments were consistent with the reduced neural reactivity account and inconsistent with the frame-remapping account.

N1pc reversal following repeated eccentric visual stimulation

Mahesh Casiraghi;Paola Sessa;Roberto Dell'Acqua;
2013

Abstract

Early event-related potential (ERP) hemispheric asymmetries recorded at occipitoparietal sites are usually observed following the sudden onset of a lateral peripheral stimulus. This is usually reflected in an onset-locked larger N1 over the posterior contralateral hemisphere relative to the ipsilateral hemisphere, an early ERP asymmetry labeled N1pc. When the peripheral sudden onset is followed by a central stimulus, or by a bilaterally balanced visual array of stimuli, these events evoke a reversed N1pc, that is, a larger N1 over the hemisphere ipsilateral to the peripheral sudden onset. This N1pc reversal has been taken as evidence for a remapping of the visual space from an absolute, retinally based frame of reference to a relative, attentionally based frame of reference that codes the spatial positions of objects relative to the peripheral sudden onset, rather than relative to the fovea. Here, we pit the reference frame-remapping account against an alternative account based on reduced neural reactivity following the peripheral sudden onset. In three experiments, we varied the spatial location of an object relative to a preceding sudden onset, and tested the opposite predictions generated by the frame-remapping and the reduced neural reactivity accounts. Taken together, the results from the present experiments were consistent with the reduced neural reactivity account and inconsistent with the frame-remapping account.
2013
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2570482
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