caa a22 4500 445353899 CHVBK 20180317142853.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s00221-011-2730-z doi (NATIONALLICENCE)springer-10.1007/s00221-011-2730-z Attention does more than modulate suppressive interactions: attending to multiple items [Elektronische Daten] [Paige Scalf, Chandramalika Basak, Diane Beck] Directing attention to a visual item enhances its representations, making it more likely to guide behavior (Corbetta et al. 1991). Attention is thought to produce this enhancement by biasing suppressive interactions among multiple items in visual cortex in favor of the attended item (e.g., Desimone and Duncan 1995; Reynolds and Heeger 2009). We ask whether target enhancement and modulation of suppressive interactions are in fact inextricably linked or whether they can be decoupled. In particular, we ask whether simultaneously directing attention to multiple items may be one means of dissociating the influence of attention-related enhancement from the effects of inter-item suppression. When multiple items are attended, suppressive interactions in visual cortex limit the effectiveness with which attention may act on their representations, presumably because "biasing” the interactions in favor of a single item is no longer possible (Scalf and Beck 2010). In this experiment, we directly investigate whether applying attention to multiple competing stimulus items has any influence on either their evoked signal or their suppressive interactions. Both BOLD signal evoked by the items in V4 and behavioral responses to those items were significantly compromised by simultaneous presentation relative to simultaneous presentation, indicating that when the items appeared at the same time, they interacted in a mutually suppressive manner that compromised their ability to guide behavior. Attention significantly enhanced signal in V4. The attentional status of the items, however, had no influence on the suppressive effects of simultaneous presentation. To our knowledge, these data are the first to explicitly decouple the effects of top-down attention from those of inter-item suppression. Springer-Verlag, 2011 Attention nationallicence Vision nationallicence fMRI nationallicence Biased competition nationallicence Scalf Paige Beckman Institute, University of Illinois at Urbana-Champaign, 405 N Mathews, 61801, Urbana, IL, USA aut Basak Chandramalika Department of Psychology, Rice University, Houston, TX, USA aut Beck Diane Beckman Institute, University of Illinois at Urbana-Champaign, 405 N Mathews, 61801, Urbana, IL, USA aut Experimental Brain Research Springer-Verlag 212/2(2011-07-01), 293-304 0014-4819 212:2<293 2011 212 221 https://doi.org/10.1007/s00221-011-2730-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2730-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Scalf Paige Beckman Institute, University of Illinois at Urbana-Champaign, 405 N Mathews, 61801, Urbana, IL, USA aut NATIONALLICENCE 700 1- Basak Chandramalika Department of Psychology, Rice University, Houston, TX, USA aut NATIONALLICENCE 700 1- Beck Diane Beckman Institute, University of Illinois at Urbana-Champaign, 405 N Mathews, 61801, Urbana, IL, USA aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 212/2(2011-07-01), 293-304 0014-4819 212:2<293 2011 212 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer