Is the Primary Visual Cortex a Center Stage for the Visual Phenomenology of Object Size?

Chouinard, Philippe A.; Ivanowich, Matthew

doi:10.1523/jneurosci.4902-13.2014

Cited by 9 publications

(5 citation statements)

References 8 publications

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“…Is such a simple computational model biologically plausible? Pooresmaeili et al, 2013 studied the effect of adaptation using fMRI and found that the activated area of cortical surface in V1, as well as V2, V3 and V4 (although not statistically significantly in V4) correlated with the perceived size (but see Chouinard & Ivanowich, 2014, for a critical review). There are also studies supporting the feedback modulation on size adaptation effect.…”

Section: Discussionmentioning

confidence: 99%

Size aftereffect is non-local

Altan

Boyacı

2020

Vision Research

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It is well known that prolonged exposure to a certain size stimulus alters the perceived size of a subsequently presented stimulus at the same location.How the rest of the visual space is affected by this size adaptation, however, has not been systematically studied before. Here, to fill this gap in literature, we tested size adaptation at the adapter location as well as the rest of the visual space. We used peripherally presented solid discs (Experiment 1) and rings (Experiment 2) as adapter and target (test) stimuli. Observers adapted to a mid-sized stimulus and judged the size of the subsequently presented smaller or larger target stimuli. Results showed that the perceived sizes of target stimuli were repelled away from the adapter size, not only at the adapter location but also at distant locations. These findings demonstrate that size adaptation causes widespread distortion of the visual space and alters perceived size. We discuss possible computational models that may underpin the perceptual effect.

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Section: Discussionmentioning

confidence: 99%

Size aftereffect is non-local

Altan

Boyacı

2020

Vision Research

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“…First, changes in perceived size, resulting from adaptation, could originate in V1. However, similar effects found in area V2 ( Pooresmaeili et al., 2013 ) pose a challenge in distinguishing between feedforward and feedback propagation of signals ( Chouinard & Ivanowich, 2014 ). Second, while there is compelling evidence demonstrating that Emmert’s illusion can elicit a commensurate distortion of V1 retinotopy ( Sperandio et al., 2012 ), V1 itself is not essential to experience this illusory percept.…”

Section: Discussionmentioning

confidence: 99%

An Orientation Dependent Size Illusion Is Underpinned by Processing in the Extrastriate Visual Area, LO1

et al. 2016

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We use the simple, but prominent Helmholtz’s squares illusion in which a vertically striped square appears wider than a horizontally striped square of identical physical dimensions to determine whether functional magnetic resonance imaging (fMRI) BOLD responses in V1 underpin illusions of size. We report that these simple stimuli which differ in only one parameter, orientation, to which V1 neurons are highly selective elicited activity in V1 that followed their physical, not perceived size. To further probe the role of V1 in the illusion and investigate plausible extrastriate visual areas responsible for eliciting the Helmholtz squares illusion, we performed a follow-up transcranial magnetic stimulation (TMS) experiment in which we compared perceptual judgments about the aspect ratio of perceptually identical Helmholtz squares when no TMS was applied against selective stimulation of V1, LO1, or LO2. In agreement with fMRI results, we report that TMS of area V1 does not compromise the strength of the illusion. Only stimulation of area LO1, and not LO2, compromised significantly the strength of the illusion, consistent with previous research that LO1 plays a role in the processing of orientation information. These results demonstrate the involvement of a specific extrastriate area in an illusory percept of size.

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“…Pooresmaeili et al (2013) found a correlation between the illusionary size changes and the activation within V1 and explained the illusion by local processes in V1, presumably triggered by the contours of the adapter. Although these data emphasize an important role of early visual areas in size adaptation, they cannot resolve the question of whether the effects observed in these regions emerge solely from feed-forward processes or may be generated via feedback processes from higher cortical regions (Chouinard & Ivanowich, 2014). In terms of a theoretical distinction, the question arises of whether size adaptation is mainly determined by stimulus properties without any or with only minor influence from endogenous and top-down settings.…”

Section: Introductionmentioning

confidence: 86%

Attention modulates visual size adaptation

2015

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The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

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Is the Primary Visual Cortex a Center Stage for the Visual Phenomenology of Object Size?

Cited by 9 publications

References 8 publications

Size aftereffect is non-local

Size aftereffect is non-local

An Orientation Dependent Size Illusion Is Underpinned by Processing in the Extrastriate Visual Area, LO1

Attention modulates visual size adaptation

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