UNIGE document Scientific Article
previous document  unige:98879  next document
add to browser collection
Title

Electrophysiological correlates of visual binding errors after bilateral parietal damage

Authors
Published in Neuroscience. 2016, vol. 337, p. 98-106
Abstract Illusory conjunctions (e.g. the confusion between the shape of one stimulus with the color of another stimulus) are the most dramatic expression of binding failures in vision. Under brief exposure or when attention is diverted illusory conjunctions may be observed in healthy participants, but they only represent a real-life problem for patients with parietal damage. However, it is unclear whether such failures reflect the impairment of early or late stages of visual processing. Here, we examined the time-course of visual processing using evoked potential measures in a patient with bilateral damage to the posterior parietal cortex presenting prominent binding failures. The patient was asked to identify colored letters that were briefly flashed to the left or right hemifield. When only one item was presented she adequately identified color or shape of left and right letters. In contrast, when presentation was bilateral she either identified the correct right shape-color combination and missed the item in the left hemifield (extinction) or combined incorrectly the right shape with the left color (illusory conjunction). Evoked potential analyses revealed a specific electrophysiological signature of illusory conjunctions, starting ∼105ms after stimulus onset over the right frontal cortex. These findings indicate that binding errors reflect failures of early stages of attentional filtering relying on the integrity of the posterior parietal cortex.
Identifiers
PMID: 27646293
Full text
Article (Published version) (1.5 MB) - document accessible for UNIGE members only Limited access to UNIGE
Structures
Research group Lésions cérébrales et attention spatiale (705)
Citation
(ISO format)
PEDRAZZINI, Elena et al. Electrophysiological correlates of visual binding errors after bilateral parietal damage. In: Neuroscience, 2016, vol. 337, p. 98-106. https://archive-ouverte.unige.ch/unige:98879

13 hits

0 download

Update

Deposited on : 2017-11-10

Export document
Format :
Citation style :