Cue-Invariant Activation in Object-Related Areas of the Human Occipital Lobe

Grill-Spector, Kalanit; Kushnir, Tamar; Edelman, Shimon; Itzchak, Y; Malach, Rafael

doi:10.1016/s0896-6273(00)80526-7

Cited by 368 publications

(262 citation statements)

References 35 publications

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“…The three ROIs (V1, MTϩ, and LOC) showed significant increases in activity in response to motion stimuli (velocity-scrambled or SFM) compared with the stationary stimuli, with MTϩ showing the largest signal increase. In response to the SFM shapes, activity increased significantly in the LOC in comparison with the velocity-scrambled control, consistent with other studies showing that the LOC integrates multiple shape cues (21,22). By contrast, both V1 and MTϩ showed significant reductions in activity during object perception (Fig.…”

Section: Methodssupporting

confidence: 90%

“…Activity in the LOC increased in response to the shape stimuli, with the 2D shapes activating the LOC significantly more than the random lines, and the 3D shapes activating the LOC more than the 2D shapes, consistent with previous findings (9,10,(21)(22)(23). By contrast, activity in V1 showed an opposite pattern: significant reductions in response to the 2D shapes compared with the random lines and significantly less activity for 3D than 2D shapes (Fig.…”

Section: Subjects and Proceduresupporting

confidence: 90%

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Shape perception reduces activity in human primary visual cortex

Murray

Kersten

Olshausen

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

408

323

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Visual perception involves the grouping of individual elements into coherent patterns that reduce the descriptive complexity of a visual scene. The physiological basis of this perceptual simplification remains poorly understood. We used functional MRI to measure activity in a higher object processing area, the lateral occipital complex, and in primary visual cortex in response to visual elements that were either grouped into objects or randomly arranged. We observed significant activity increases in the lateral occipital complex and concurrent reductions of activity in primary visual cortex when elements formed coherent shapes, suggesting that activity in early visual areas is reduced as a result of grouping processes performed in higher areas. These findings are consistent with predictive coding models of vision that postulate that inferences of high-level areas are subtracted from incoming sensory information in lower areas through cortical feedback.O ne of the extraordinary capabilities of the human visual system is its ability to rapidly group elements in a complex visual scene, a process that can greatly simplify the description of an image. For example, a collection of parallel lines can be described as a single texture pattern without specifying the location, length, and orientation of each element within the pattern. Such grouping processes are reflected in the activities of neurons at various stages of the visual system. For example, the response of a neuron in primary visual cortex (V1) to a single visual element can be suppressed if the element in its receptive field shares the same orientation as surrounding elements, or enhanced if orientations differ (1). These pattern context effects in V1 are thought to be mediated by both local connections (2) and interactions with higher areas (3).In natural scenes, elements are often grouped when they are perceived as belonging to the same object. This case is particularly interesting from a physiological perspective because object shape is a feature that is represented only in higher stages of the visual system, so any influence of perceived shape on lower areas would require feedback processes. Although feedback is generally thought of as a process where activity in lower areas is enhanced by activity occurring in higher areas, recent work on probabilistic models has pointed to the importance of a phenomenon termed ''explaining away'': a competition that occurs between alternative hypotheses when attempting to infer the probable cause of an event (4). When applied to models of visual perception, perceptual hypotheses are thought to compete via feedback connections from higher visual areas projecting their predictions about the stimulus to lower stages, where they are then subtracted from incoming data. According to such predictive coding models, the activity of neurons in lower stages will decrease when neurons in higher stages can ''explain'' a visual stimulus (5, 6). These models can be contrasted with traditional feature-detection models, which posit that...

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Section: Methodssupporting

confidence: 90%

Section: Subjects and Proceduresupporting

confidence: 90%

Shape perception reduces activity in human primary visual cortex

Murray

Kersten

Olshausen

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

408

323

View full text Add to dashboard Cite

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“…Indeed, in Kristjánsson et al's study, there was evidence for repetition suppression on target-repeated trials in inferior temporal areas as well as in fronto-parietal areas. Inferior temporal areas are known to process object-related information such as color and shape (see, e.g., Grill-Spector, Kushnir, Edelman, Itzchak, & Malach, 1998;Grill-Spector & Malach, 2001), whereas the fronto-parietal network is believed to control spatial attention (Kastner & Ungerleider, 2001;LaBar, Gitelman, Parrish, & Mesulam, 1999). Finally, eye movement data on three-item oddball displays like the ones used here also showed that participants were actually relatively bad at fixating the target when the target on the current trial differed in color identity from that on the previous trial (Becker, 2008;Caddigan & Lleras, 2010).…”

Section: Discussionmentioning

confidence: 54%

Exploring the contributions of spatial and non-spatial working memory to priming of pop-out

Ahn

Patel

Buetti

et al. 2017

Atten Percept Psychophys

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Priming of pop-out (PoP) refers to the facilitation of performance that occurs when a target-defining feature is repeated across consecutive trials in a pop-out oddball search task. The underlying mechanism of PoP has been poorly understood and raises important questions about how our visual system is guided by past experiences, even during bottom-up processing. Lee, Mozer, and Vecera (Attention, Perception, & Psychophysics, 71, 1059-1071, 2009) demonstrated that PoP remained unaffected by a concurrent non-spatial visual working memory (VWM) load, and they concluded that PoP occurs through feature gain modulation, essentially eliminating the contribution of memory representations in VWM to PoP. In the present study, we followed up on those results by (a) replicating the null effect of non-spatial VWM load on PoP and (b) examining the effect of spatial VWM load on PoP. The results showed that spatial VWM load does interfere with PoP, supporting the notion that spatial VWM is involved in PoP. In Experiment 2, we extended this finding by manipulating VWM load and observing its consequence on the magnitude of PoP. Increasing spatial VWM load decreased the amount of PoP observed, in a dose-dependent manner, whereas changes in non-spatial VWM load did not. Contrary to Lee et al.'s conclusions, these results suggest that VWM resources appear to contribute to the occurrence of PoP, supporting the theory that PoP is, in fact, a multilevel process in which the deployment of spatial attention, relying on VWM representations, plays an important role.

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“…Our previous source-imaging studies using frequency tagging have suggested that the LOC is tuned for the configuration of a small figure on a larger background (Appelbaum et al, 2010) and that LOC responses to figures are largely cue-invariant (Appelbaum et al, 2006(Appelbaum et al, , 2012. Cue-invariance in LOC has also been found with fMRI (Grill-Spector et al, 1998).…”

Section: Tuning For Shapementioning

confidence: 80%

“…In fMRI studies the LOC is activated more by intact than by scrambled images of objects (Grill-Spector et al, 1998;Kourtzi and Kanwisher, 2000;Malach et al, 1995). Moreover, the LOC contains a representation of the perceived shape of objects (Kourtzi and Kanwisher, 2001;Vinberg and Grill-Spector, 2008).…”

Section: Tuning For Shapementioning

confidence: 99%

The time course of shape discrimination in the human brain

et al. 2013

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The lateral occipital cortex (LOC) activates selectively to images of intact objects versus scrambled controls, is selective for the figure-ground relationship of a scene, and exhibits at least some degree of invariance for size and position. Because of these attributes, it is considered to be a crucial part of the object recognition pathway. Here we show that human LOC is critically involved in perceptual decisions about object shape. High-density EEG was recorded while subjects performed a threshold-level shape discrimination task on texture-defined figures segmented by either phase or orientation cues. The appearance or disappearance of a figure region from a uniform background generated robust visual evoked potentials throughout retinotopic cortex as determined by inverse modeling of the scalp voltage distribution. Contrasting responses from trials containing shape changes that were correctly detected (hits) with trials in which no change occurred (correct rejects) revealed stimulus-locked, target-selective activity in the occipital visual areas LOC and V4 preceding the subject's response. Activity that was locked to the subjects' reaction time was present in the LOC. Response-locked activity in the LOC was determined to be related to shape discrimination for several reasons: shape-selective responses were silenced when subjects viewed identical stimuli but their attention was directed away from the shapes to a demanding letter discrimination task; shape-selectivity was present across four different stimulus configurations used to define the figure; LOC responses correlated with participants' reaction times. These results indicate that decision-related activity is present in the LOC when subjects are engaged in threshold-level shape discriminations.

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Cue-Invariant Activation in Object-Related Areas of the Human Occipital Lobe

Cited by 368 publications

References 35 publications

Shape perception reduces activity in human primary visual cortex

Shape perception reduces activity in human primary visual cortex

Exploring the contributions of spatial and non-spatial working memory to priming of pop-out

The time course of shape discrimination in the human brain

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