Bottom-Up Dependent Gating of Frontal Signals in Early Visual Cortex

@article{citeulike:3016683, abstract = {The frontal eye field (FEF) is one of several cortical regions thought to modulate sensory inputs. Moreover, several hypotheses suggest that the FEF can only modulate early visual areas in the presence of a visual stimulus. To test for bottom-up gating of frontal signals, we microstimulated subregions in the FEF of two monkeys and measured the effects throughout the brain with functional magnetic resonance imaging. The activity of higher-order visual areas was strongly modulated by FEF stimulation, independent of visual stimulation. In contrast, FEF stimulation induced a topographically specific pattern of enhancement and suppression in early visual areas, but only in the presence of a visual stimulus. Modulation strength depended on stimulus contrast and on the presence of distractors. We conclude that bottom-up activation is needed to enable top-down modulation of early visual cortex and that stimulus saliency determines the strength of this modulation. 10.1126/science.1153276}, author = {Ekstrom, Leeland B. and Roelfsema, Pieter R. and Arsenault, John T. and Bonmassar, Giorgio and Vanduffel, Wim }, citeulike-article-id = {3016683}, doi = {http://dx.doi.org/10.1126/science.1153276}, journal = {Science}, keywords = {fef, general, wow}, month = {July}, number = {5887}, pages = {414--417}, posted-at = {2008-07-18 08:20:38}, priority = {4}, title = {Bottom-Up Dependent Gating of Frontal Signals in Early Visual Cortex}, url = {http://dx.doi.org/10.1126/science.1153276}, volume = {321}, year = {2008} }

TY - JOUR ID - citeulike:3016683 L3 - citeulike-article-id:3016683 TI - Bottom-Up Dependent Gating of Frontal Signals in Early Visual Cortex JF - Science VL - 321 IS - 5887 SP - 414 EP - 417 N2 - The frontal eye field (FEF) is one of several cortical regions thought to modulate sensory inputs. Moreover, several hypotheses suggest that the FEF can only modulate early visual areas in the presence of a visual stimulus. To test for bottom-up gating of frontal signals, we microstimulated subregions in the FEF of two monkeys and measured the effects throughout the brain with functional magnetic resonance imaging. The activity of higher-order visual areas was strongly modulated by FEF stimulation, independent of visual stimulation. In contrast, FEF stimulation induced a topographically specific pattern of enhancement and suppression in early visual areas, but only in the presence of a visual stimulus. Modulation strength depended on stimulus contrast and on the presence of distractors. We conclude that bottom-up activation is needed to enable top-down modulation of early visual cortex and that stimulus saliency determines the strength of this modulation. 10.1126/science.1153276 KW - fef KW - general KW - wow AU - Ekstrom, Leeland AU - Roelfsema, Pieter AU - Arsenault, John AU - Bonmassar, Giorgio AU - Vanduffel, Wim PY - 2008/07/18/ UR - http://dx.doi.org/10.1126/science.1153276 ER -