The speed of context integration in the visual cortex

Sugihara, Tadashi; Qiu, Fangtu T.; Heydt, Rüdiger von der

doi:10.1152/jn.00928.2010

Cited by 50 publications

(60 citation statements)

References 49 publications

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“…This strongly suggests that the integration of information across space that is necessary for the illusion to become effective is not mediated by rapid feedforward mechanisms alone but is rather depending on more timeconsuming mechanisms. This might be modulatory feedback from higher to lower levels, or horizontal connections within levels of the visual hierarchy-given that they are even slower than feedback connections (Sugihara, Qiu & von der Heydt, 2011).…”

Section: Discussionmentioning

confidence: 99%

Temporal processing characteristics of the Ponzo illusion

Schmidt

Haberkamp

2015

Psychological Research

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Many visual illusions result from assumptions of our visual system that are based on its long-term adaptation to our visual environment. Thus, visual illusions provide the opportunity to identify and learn about these fundamental assumptions. In this paper, we investigate the Ponzo illusion. Although many previous studies researched visual processing of the Ponzo illusion, only very few considered temporal processing aspects. However, it is well known that our visual percept is modulated by temporal factors. First, we used the Ponzo illusion as prime in a response priming task to test whether it modulates subsequent responses to the longer (or shorter) of two target bars. Second, we used the same stimuli in a perceptual task to test whether the Ponzo illusion is effective for very short presentation times (12 ms). We observed considerable priming effects that were of similar magnitude as those of a control condition. Moreover, the variations in the priming effects as a function of prime-target stimulus-onset asynchrony were very similar to that of the control condition. However, when analyzing priming effects as a function of participants' response speed, effects for the Ponzo illusion increased in slower responses. We conclude that although the illusion is established rapidly within the visual system, the full integration of context information is based on more time-consuming and later visual processing.

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Section: Discussionmentioning

confidence: 99%

Temporal processing characteristics of the Ponzo illusion

Schmidt

Haberkamp

2015

Psychological Research

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“…This relationship has been suggested in several previous studies. For example, electrophysiological recordings in monkeys concluded, based on latency information, that an explicit assignment of figure and ground is made in area V1 based upon signals coming from extrastriate areas (40)(41)(42)(43). In another study, figure−ground modulation disappeared following surgical removal of V4 (44), which, when combined with a disrupted ability to perceive illusory contours following V4 lesions (26), suggests that the interplay between early visual areas is central to the visual completion of illusory figures.…”

Section: Surface Completion As a Possible Basis For Neural Enhancementmentioning

confidence: 99%

Receptive field focus of visual area V4 neurons determines responses to illusory surfaces

Cox

Schmid

Peters

et al. 2013

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

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Illusory figures demonstrate the visual system's ability to infer surfaces under conditions of fragmented sensory input. To investigate the role of midlevel visual area V4 in visual surface completion, we used multielectrode arrays to measure spiking responses to two types of visual stimuli: Kanizsa patterns that induce the perception of an illusory surface and physically similar control stimuli that do not. Neurons in V4 exhibited stronger and sometimes rhythmic spiking responses for the illusion-promoting configurations compared with controls. Moreover, this elevated response depended on the precise alignment of the neuron's peak visual field sensitivity (receptive field focus) with the illusory surface itself. Neurons whose receptive field focus was over adjacent inducing elements, less than 1.5°away, did not show response enhancement to the illusion. Neither receptive field sizes nor fixational eye movements could account for this effect, which was present in both single-unit signals and multiunit activity. These results suggest that the active perceptual completion of surfaces and shapes, which is a fundamental problem in natural visual experience, draws upon the selective enhancement of activity within a distinct subpopulation of neurons in cortical area V4.visual perception | illusory contours | modal completion | nonhuman primate | visual cortex V isual illusions are valuable stimuli for studying the neural basis of visual processing because they reveal the brain's internal mechanisms for interpreting sensory input. Illusory figures, for example, exploit the visual system's capacity to construct contours, shapes, and surfaces despite the lack of a continuous physical border (1, 2). Illusory figures are perceived by a range of phylogenetically diverse species, including monkeys, cats, owls, and bees, pointing to perceptual completion as a fundamental aspect of natural vision (3).Neural correlates of illusory figures have been found in a wide range of brain areas. Recordings in monkeys revealed that illusory figures evoke spiking responses from neurons in visual areas as early as V1 and V2 and as late as the inferotemporal cortex (4-9). Neuroimaging studies in humans similarly found responses to illusory figures throughout visual cortex (10-13).Several theoretical models postulate mechanisms of illusory figure perception (14-19). A common feature of these models is spatial integration of the inducing elements combined with an active interpolation to complete the surface. These processes are frequently assigned to neurons in midlevel areas, whose receptive fields are large enough to cover separate elements yet sensitive enough to distinguish between local features such as orientation, curvature, and colinearity (20,21). A range of evidence suggests that visual area V4 in particular may play an active role in surface completion. First, the receptive fields of V4 neurons are large by comparison with V1 and V2 receptive fields and are therefore able to integrate information across spatially separated stimulus ...

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“…Processing of illusory contours was shown to be generated by relatively local integration of signals implemented by feedforward signals (e.g., Heitger, von der Heydt, Peterhans, Rosenthaler, & Kübler, 1998;cf. SeydellGreenwald & Schmidt, 2012), while visual completion is most probably implemented by feedback activation from higher levels (Sugihara, Qiu, & von der Heydt, 2011;Zhang & von der Heydt, 2010). Note that this attribution of modal and amodal completion to feedforward and feedback activation, respectively, is not without controversy.…”

Section: Indicators Of Feedforward Processingmentioning

confidence: 99%

Activation of response force by self-splitting objects: Where are the limits of feedforward Gestalt processing?

2014

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Most objects can be recognized easily even when they are partly occluded. This also holds when several overlapping objects share the same surface features (self-splitting objects) which is an illustration of the grouping principle of Good Gestalt. We employed outline and filled contour stimuli in a primed flanker task to test whether the processing of self-splitting objects is in accordance with a simple feedforward model. We obtained priming effects in response time and response force for both types of stimuli, even when increasing the number of occluders up to three. The results for outline contours were in full accordance with a feedforward account. This was not the case for the results for filled contours (i.e., for self-splitting objects), especially under conditions of strong occlusion. We conclude that the implementation of the Good Gestalt principle is fast but still based on recurrent processing.

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The speed of context integration in the visual cortex

Abstract: Sugihara T, Qiu FT, von der Heydt R. The speed of context integration in the visual cortex.

Cited by 50 publications

References 49 publications

Temporal processing characteristics of the Ponzo illusion

Temporal processing characteristics of the Ponzo illusion

Receptive field focus of visual area V4 neurons determines responses to illusory surfaces

Activation of response force by self-splitting objects: Where are the limits of feedforward Gestalt processing?

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