A high-density electrical mapping and fMRI investigation of biased intersensory attentional sets
Poster Presentation

Manuel Gomez-Ramirez
Cognitive Neuroscience Program at The City College of The City University of New York

*Glenn Wylie
Nathan S. Kline Institute

*John Foxe
Cognitive Neuroscience Program at The City College of The City University of New York

     Abstract ID Number: 114
     Full text: Not available
     Last modified: March 21, 2005
     Presentation date: 06/06/2005 11:30 AM in MART Auditorium
     (View Schedule)

Abstract
Studies of selective attentional deployment to different sensory modalities have typically used so-called “endogenous” cueing paradigms where symbolic cues are presented on a screen or over headphones. Typically, it is thought that these symbolic cues selectively direct the subject’s attention to one of two or three sensory modalities where a difficult discrimination task is performed within the cued modality. We contend that such cues are only minimally effective in inducing endogenous attentional mechanisms because they are externally presented and thus are not generated under the control of the subject’s attentional “mind set”. In the present EEG and fMRI study, we introduce a modified inter-sensory attention task where we give control back to the subjects and allow them to initiate a trial whenever they “feel ready to make an effective attentional deployment” to the sensory modality of their choosing. In contrast to the traditional paradigm, these “cues” are internally generated and entirely under control of the subject. Indeed, we find enhanced attentional modulations under this novel paradigm. For example, attended visual stimuli presented under this novel paradigm elicited greater C1 and N1 responses when compared to stimuli presented under the traditional paradigm. One implication of our results is that selective attentional filtering may be deployed to earlier processing stages when attentional deployment is “truly” voluntary.