Competition in Visual Cortex Impedes Attention to Multiple Items

Scalf, Paige E.; Beck, Diane M.

doi:10.1523/jneurosci.4207-09.2010

Cited by 55 publications

(55 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The resulting d' scores provide a more precise measure of performance than accuracy percentages alone, with higher scores indicating better performance. This analysis revealed a mean d' of 2.36, which falls within the range of normal d' scores that others have observed on this task (e.g., Scalf et al, 2011;Scalf & Beck, 2010). Therefore, although accuracy was at floor, the d' analysis…”

Section: Behavioral Resultssupporting

confidence: 82%

“…Competition-mediated suppression between multiple objects has been observed in visual areas as low as V1/V2 and as high as the inferior temporal cortex (IT) via single-cell recording in monkeys (Miller et al, 1993;Reynolds et al, 1999) and functional magnetic resonance imaging (fMRI) in humans (Beck & Kastner, 2005;Kastner, De Weerd, Desimone, & Ungerleider, 1998;Scalf & Beck, 2010;see Beck & Kastner, 2009, for a review).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Neural evidence for competition-mediated suppression in the perception of a single object

Cacciamani

Scalf

Peterson

2015

Cortex

View full text Add to dashboard Cite

. (2015) 'Neural evidence for competition-mediated suppression in the perception of a single ob ject. ', Cortex., Further information on publisher's website: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Multiple objects compete for representation in visual cortex. Competition may also underlie the perception of a single object. Computational models implement object perception as competition between units on opposite sides of a border. The border is assigned to the winning side, which is perceived as an object (or " figure"), whereas the other side is perceived as a shapeless ground. Behavioral experiments suggest that the ground is inhibited to a degree that depends on the extent to which it competed for object status, and that this inhibition is relayed to low-level brain areas. Here, we used fMRI to assess activation for ground regions of task-irrelevant novel silhouettes presented in the left or right visual field (LVF or RVF) while participants performed a difficult task at fixation. Silhouettes were designed so that the insides would win the competition for object status. The outsides (grounds) suggested portions of familiar objects in half of the silhouettes and novel objects in the other half. Because matches to object memories affect the competition, these two types of silhouettes operationalized, respectively, high competition and low competition from the grounds. The results showed that activation corresponding to ground regions was reduced for high-vs. low-competition silhouettes in V4, where receptive fields (RFs) are large enough to encompass the familiar objects in the grounds, and in V1/V2, where RFs are much smaller. These results support a theory of object perception involving competitionmediated ground suppression and feedback from higher to lower levels. This pattern of results was observed in the left hemisphere (RVF), but not in the right hemisphere (LVF). One explanation of the lateralized findings is that task-irrelevant silhouettes in the RVF captured attention, allowing us to observe these effects, whereas those in the LVF did not. Experiment 2 provided preliminary behavioral evidence consistent with this possibility.

show abstract

Section: Behavioral Resultssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Neural evidence for competition-mediated suppression in the perception of a single object

Cacciamani

Scalf

Peterson

2015

Cortex

View full text Add to dashboard Cite

show abstract

“…Four high-resolution (1 mm) SPGR T1-weighted images were collected to submit to Freesurfer Fischl et al, 1999Fischl et al, , 2001 for averaging, segmentation, and flatmapping. Further details of retinotopic mapping and analysis are identical to those reported by Scalf and Beck (2010).…”

Section: Visual Cortex Analysis Proceduresmentioning

confidence: 68%

“…The procedures used during this session are the same as those described in Scalf and Beck (2010) and are derived from those established by Sereno et al (1995) and adapted by Kastner et al (1998). Briefly, each quadrant of visual cortex (upper/lower, left/right) represents 908 of the visual field in a retinotopic manner.…”

Section: Visual Cortex Analysis Proceduresmentioning

confidence: 99%

The perirhinal cortex modulates V2 activity in response to the agreement between part familiarity and configuration familiarity

Peterson¹,

Cacciamani²,

Barense³

et al. 2012

Hippocampus

View full text Add to dashboard Cite

ABSTRACT:Research has demonstrated that the perirhinal cortex (PRC) represents complex object-level feature configurations, and participates in familiarity versus novelty discrimination. Barense et al. [(in press) Cerebral Cortex, 22:11, doi:10.1093/cercor/bhr347] postulated that, in addition, the PRC modulates part familiarity responses in lower-level visual areas. We used fMRI to measure activation in the PRC and V2 in response to silhouettes presented peripherally while participants maintained central fixation and performed an object recognition task. There were three types of silhouettes: Familiar Configurations portrayed realworld objects; Part-Rearranged Novel Configurations created by spatially rearranging the parts of the familiar configurations; and Control Novel Configurations in which both the configuration and the ensemble of parts comprising it were novel. For right visual field (RVF) presentation, BOLD responses revealed a significant linear trend in bilateral BA 35 of the PRC (highest activation for Familiar Configurations, lowest for Part-Rearranged Novel Configurations, with Control Novel Configurations in between). For left visual field (LVF) presentation, a significant linear trend was found in a different area (bilateral BA 38, temporal pole) in the opposite direction (Part-Rearranged Novel Configurations highest, Familiar Configurations lowest). These data confirm that the PRC is sensitive to the agreement in familiarity between the configuration level and the part level. As predicted, V2 activation mimicked that of the PRC: for RVF presentation, activity in V2 was significantly higher in the left hemisphere for Familiar Configurations than for Part-Rearranged Novel Configurations, and for LVF presentation, the opposite effect was found in right hemisphere V2. We attribute these patterns in V2 to feedback from the PRC because receptive fields in V2 encompass parts but not configurations. These results reveal two new aspects of PRC function: (1) it is sensitive to the congruency between the familiarity of object configurations and the parts comprising those configurations and (2) it likely modulates familiarity responses in visual area V2. V V C 2012 Wiley Periodicals, Inc.

show abstract

“…Given that the eccentricities of the ground targets were equivalent for the two types of silhouettes, the difference represents the degree to which suppression was greater on the grounds of high-competition than on those of low-competition silhouettes, and thus serves to measure competition-strength-dependent suppression (for similar use of a suppression index, see Kastner, De Weerd, Desimone, & Ungerleider, 1998;Scalf & Beck, 2010). If ground suppression is no greater for high-competition than for low-competition silhouettes, the difference between the (S + E) indices for high-competition and low-competition silhouettes should be zero, whereas if greater suppression is applied to grounds that compete more strongly for figural status, the difference between the (S + E) indices for high-competition and low-competition silhouettes should be greater than zero.…”

Section: Resultsmentioning

confidence: 99%

Competition-strength-dependent ground suppression in figure–ground perception

Salvagio

Cacciamani

Peterson

2012

Atten Percept Psychophys

View full text Add to dashboard Cite

Figure-ground segregation is modeled as inhibitory competition between objects that might be perceived on opposite sides of borders. The winner is the figure; the loser is suppressed, and its location is perceived as shapeless ground. Evidence of ground suppression would support inhibitory competition models and would contribute to explaining why grounds are shapeless near borders shared with figures, yet such evidence is scarce. We manipulated whether competition from potential objects on the ground side of figures was high (i.e., portions of familiar objects were potentially present there) or low (novel objects were potentially present). We predicted that greater competition would produce more ground suppression. The results of two experiments in which suppression was assessed via judgments of the orientation of target bars confirmed this prediction; a third experiment showed that ground suppression is short-lived. Our findings support inhibitory competition models of figure assignment, in particular, and models of visual perception entailing feedback, in general.Keywords Figure- The visual world contains an overwhelming amount of information, yet it seems immediately and effortlessly organized into differentiable objects. Perceptual organization is essential for interacting with the world, but relatively little is known about how it is accomplished. Vital to perceptual organization is the determination of which of two contiguous regions is the object (or figure) at the shared border, and which simply appears as a shapeless background to the object-what has been called figure-ground perception (Rubin, 1915(Rubin, /1958. Critically, shape is attributed to the figure, whereas no shape is attributed to the ground near the border that it shares with the figure.Numerous computational models of figure-ground perception have employed competition between figure attributes on opposite sides of borders in the visual input to resolve figure-ground perception (e.g

show abstract

Competition in Visual Cortex Impedes Attention to Multiple Items

Cited by 55 publications

References 46 publications

Neural evidence for competition-mediated suppression in the perception of a single object

Neural evidence for competition-mediated suppression in the perception of a single object

The perirhinal cortex modulates V2 activity in response to the agreement between part familiarity and configuration familiarity

Competition-strength-dependent ground suppression in figure–ground perception

Contact Info

Product

Resources

About