Document Detail

FEF-microstimulation causes task-dependent modulation of occipital fMRI activity.
MedLine Citation:
PMID:  23186918     Owner:  NLM     Status:  Publisher    
Electrical microstimulation of FEF (FEF-EM) modulates neuronal activity in area V4 (Moore and Armstrong, 2003) and elicits functional magnetic resonance imaging (fMRI) activations in visual cortex in a bottom-up dependent manner (Ekstrom et al., 2008). Here we test the hypothesis that FEF-EM-induced modulations of fMRI activity are also function of task demands, which would suggest top-down dependent gating of FEF signals in early visual cortex. We scanned two monkeys performing a visually guided saccade task; a passive fixation task with a very similar visual display; and a passive fixation task without peripheral dots. We found increased effects of FEF-EM on fMRI-activity in visual cortex during saccades compared to fixation, indicating that the FEF-EM induced modulation is task-dependent. Finally, the effect of FEF-EM is mainly present in voxels which were less activated by visual stimuli in the absence of electrical stimulation. Our results show that the FEF-EM-induced pattern of activation in early visual cortex is topographically specific and more pronounced during increased task demands. These results fit with models suggesting that FEF is an important source modulating activity in early sensory cortex and that these influences can be enhanced by coincident bottom-up or top-down signals.
Elsie Premereur; Peter Janssen; Wim Vanduffel
Related Documents :
22906088 - Models of hemispheric specialization in facial emotion perception-a reevaluation.
11922118 - A matching advantage for dynamic human faces.
18087958 - A negative compatibility effect in priming of emotional faces.
8811958 - Lexical priming by pictures and words in normal aging and in dementia of the alzheimer'...
23485548 - Motor preparation is delayed for both directly and indirectly cued movements during an ...
8609298 - Phonemic restoration and integration during dichotic listening.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-11-24
Journal Detail:
Title:  NeuroImage     Volume:  -     ISSN:  1095-9572     ISO Abbreviation:  Neuroimage     Publication Date:  2012 Nov 
Date Detail:
Created Date:  2012-11-28     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9215515     Medline TA:  Neuroimage     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2012. Published by Elsevier Inc.
Lab. voor Neuro- & Psychofysiologie, KU Leuven, Leuven, Belgium.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Cortical cross-frequency coupling predicts perceptual outcomes.
Next Document:  Endogenous glucocorticoid increases the basal level of Treg-Th17 balance under early phase of stress...