Bottom-up dependent gating of frontal signals in early visual cortex

Leeland B. Ekstrom, Pieter R. Roelfsema, John T. Arsenault, Giorgio Bonmassar, Wim Vanduffel

Research output: Contribution to journalArticleAcademicpeer-review

260 Citations (Scopus)

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
Original languageEnglish
Pages (from-to)414-417
JournalScience
Volume321
Issue number5887
DOIs
Publication statusPublished - 2008

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