Journal Article


John J. Foxe
Richard B. Reilly
Barak A. Pearlmutter
Simon P. Kelly
Edmund C. Lalor



functional magnetic resonance imaging spatial analysis computer science novel the spectrum analysis steady state visual evoked potential visual event related potential

Isolating endogenous visuo-spatial attentional effects using the novel visual-evoked spread spectrum analysis (VESPA) technique (2007)

Abstract In natural visual environments, we use attention to select between relevant and irrelevant stimuli that are presented simultaneously. Our attention to objects in our visual field is largely controlled endogenously, but is also affected exogenously through the influence of novel stimuli and events. The study of endogenous and exogenous attention as separate mechanisms has been possible in behavioral and functional imaging studies, where multiple stimuli can be presented continuously and simultaneously. It has also been possible in electroencephalogram studies using the steady-state visual-evoked potential (SSVEP); however, it has not been possible in conventional event-related potential (ERP) studies, which are hampered by the need to present suddenly onsetting stimuli in isolation. This is unfortunate as the ERP technique allows for the analysis of human physiology with much greater temporal resolution than functional magnetic resonance imaging or the SSVEP. While ERP studies of endogenous attention have been widely reported, these experiments have a serious limitation in that the suddenly onsetting stimuli, used to elicit the ERP, inevitably have an exogenous, attention-grabbing effect. Recently we have shown that it is possible to derive separate event-related responses to concurrent, continuously presented stimuli using the VESPA (visual-evoked spread spectrum analysis) technique. In this study we employed an experimental paradigm based on this method, in which two pairs of diagonally opposite, non-contiguous disc-segment stimuli were presented, one pair to be ignored and the other to be attended. VESPA responses derived for each pair showed a strong modulation at 90–100 ms (during the visual P1 component), demonstrating the utility of the method for isolating endogenous visuospatial attention effects.
Collections Ireland -> Maynooth University -> Subject = Science & Engineering: Computer Science
Ireland -> Maynooth University -> Subject = Science & Engineering
Ireland -> Maynooth University -> Type = Article
Ireland -> Maynooth University -> Academic Unit = Faculty of Science and Engineering
Ireland -> Maynooth University -> Status = Published
Ireland -> Maynooth University -> Open Access DRIVERset
Ireland -> Maynooth University -> Academic Unit = Faculty of Science and Engineering: Computer Science

Full list of authors on original publication

John J. Foxe, Richard B. Reilly, Barak A. Pearlmutter, Simon P. Kelly, Edmund C. Lalor

Experts in our system

John J Foxe
Trinity College Dublin
Total Publications: 43
Richard Reilly
Trinity College Dublin
Total Publications: 185
Barak A. Pearlmutter
Maynooth University
Total Publications: 130
Simon P Kelly
University College Dublin
Total Publications: 42
Edmund C Lalor
Trinity College Dublin
Total Publications: 54