Redundancy gains in retinotopic cortex

Abstract

It is widely claimed that interactions among simultaneously presented visual stimuli are suppressive and that these interactions primarily occur when stimuli fall within the same receptive field (Desimone and Duncan 1995). Here, we show evidence for a novel form of interaction between simultaneously presented but distant stimuli that does not fit either pattern. To examine interactions between simultaneously presented stimuli, we measure the response to a single stimulus as a function of whether or not other stimuli are also presented simultaneously, and we further ask how the response to a given stimulus is affected by whether the simultaneously present stimuli are identical or different from each other. Our method reveals a new phenomenon of "redundancy gain:" the visual response to a stimulus is higher when accompanied by identical stimuli than when that stimulus is presented alone, even though the stimuli are displayed in separate visual quadrants. This pattern is observed throughout the visual hierarchy, including V1 and V2, and we show that it is distinct from the well-known simultaneous suppression effect (Kastner et al. 1998). We propose that the redundancy gain in early retinotopic cortex results from feedback from higher visual areas and may underlie perceptual averaging and other ensemble coding phenomena observed behaviorally.

Integration of identity and emotion information in faces: fMRI evidence

“…Recently, Shim and colleagues (2013) examined mechanisms of redundancy gain in complex objects (such as human faces, houses, scenes) by measuring BOLD responses to a single stimulus as a function of whether or not other stimuli are also presented simultaneously. The authors argued that the redundancy gain observed at early retinotopic cortex resulted from feedback from higher visual areas and might underlie perceptual averaging and other ensemble coding phenomena observed behaviorally (Shim, Jiang, & Kanwisher, 2013). Similar findings were reported in other studies on redundancy gains (Jiang, Kwon, Shim, & Won, 2010;Sweeny, Haroz, & Whitney, 2013).…”

Similarity effects in visual working memory

“…Multiple, simultaneously presented stimuli are known to compete for neuronal representation (Desimone & Duncan, 1995). Such competition could conceivably be greater for dissimilar than similar faces during perceptual encoding (Shim, Jiang, & Kanwisher, 2013). If the similarity advantage shown in Experiment 1 was due solely to reduced neural competition for similar faces during perceptual encoding, then it should be largely eliminated in Experiment 2.…”

A bilateral N2pc (N2pcb) component is elicited by search targets displayed on the vertical midline

“…This finding is congruent with the hypothesis of a bilateral early sensory representation for midline targets. Such bilateral representations have been shown to give rise to the so‐called “stimulus redundancy gain” effect (Miller & Van Nes, ; Shim, Jiang, & Kanwisher, ), namely the faster detection speed for identical stimuli displayed in both visual hemifields relative to when a single stimulus is displayed in either visual hemifield. In spite of its intuitive appeal of this hypothesis, it should be noted that there was no direct correspondence between this particular behavioral effect and the ERP findings reported in the present study.…”