Inter-individual differences in the polarity of early visual responses and attention effects
| Autor: | Alice Mado Proverbio, Marzia Del Zotto, Alberto Zani |
|---|---|
| Přispěvatelé: | Proverbio, A, Del Zotto, M, Zani, A, Proverbio, Am, DEL ZOTTO, M |
| Rok vydání: | 2007 |
| Předmět: |
Adult
Male medicine.medical_specialty genetic structures Visual N1 Sensory system Visual evoked potentials Neuropsychological Tests Electroencephalography Audiology Stimulus (physiology) M-PSI/02 - PSICOBIOLOGIA E PSICOLOGIA FISIOLOGICA Developmental psychology C1 Orientation spatial attention Reaction Time medicine Humans Visual attention Attention Visual Pathways Object-based attention Visual Cortex Observer Variation medicine.diagnostic_test General Neuroscience object-based attention Categorization Space Perception Visual Perception Evoked Potentials Visual Female VEP Psychology Photic Stimulation ERP |
| Zdroj: | Neuroscience Letters. 419:131-136 |
| ISSN: | 0304-3940 |
| DOI: | 10.1016/j.neulet.2007.04.048 |
| Popis: | While there is a general agreement about the sensory properties of the early-latency C1 (P/N80) and P1 components of visual evoked potentials (VEPs), the literature is not consistent about the timing of modulatory attention effects at an early sensory stage for either space- or object-based stimulus features. The aim of this study was to investigate whether inter-individual differences in VEP morphology might affect the nature and polarity of amplitude changes via selective visual attention. EEG was recorded in 20 right-handed individuals while they viewed drawings of familiar objects presented slightly lateralized and performed a categorization task. It consisted in paying attention and responding to a conjunction of space and object features. On the basis of VEP morphology, and independently of task factors, subjects were subdivided in two groups: one group exhibited a prominent N80 and the other a prominent P80 in the same latency range from the same electrode sites. RTs to targets were identical in the two groups, suggesting that morphology was independent of task-related factors. VEP morphology affected the direction and amplitude of spatial and non-spatial attention effects. While attention effects always resulted in increased positivity for the P80 group (at both the C1 and P1 levels), shape relevance was associated with enhanced N80 and P1 responses in the N80 group. These data provide evidence for an inversion of attention effects, in addition to inversion of C1 polarity, in people exhibiting negative C1 at mesial occipital sites. (c) 2007 Elsevier Ireland Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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