Eccentricity-dependent temporal contrast tuning in human visual cortex measured with fMRI

Himmelberg, Marc M.; Wade, Alex R.

doi:10.1016/j.neuroimage.2018.09.049

Cited by 33 publications

(40 citation statements)

References 59 publications

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“…This finds support in previous studies in which magnifying stimulus size alone accounted for eccentricity effects in visual search tasks (Carrasco & Frieder, 1997;Chan & Courtney, 1998), temporal contrast sensitivity (Himmelberg & Wade, 2019), and letter recognition (Anstis, 1974;Farrell & Desmarais, 1990;Higgins, Arditi, & Knoblauch, 1996). If these eccentricity-dependent differences in sensitivity can be accounted for by stimulus size alone, it is reasonable to theorize that isoeccentric differences in contrast sensitivity are also rooted in the differences in the spatial scale of cortical representations (i.e.…”

Section: Eccentricity-dependent Decreases In Contrast Sensitivity At supporting

confidence: 82%

Stimulus-dependent contrast sensitivity asymmetries around the visual field

Himmelberg

Winawer

Carrasco

2020

Preprint

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AbstractAsymmetries in visual performance at isoeccentric locations are known as performance fields. At a fixed eccentricity, visual performance is best along the horizontal, intermediate along the lower vertical, and poorest along the upper vertical meridian. These performance fields are pervasive across a range of visual tasks, including those mediated by contrast sensitivity. However, contrast performance fields have not been characterized with a systematic manipulation of stimulus spatial frequency, eccentricity, and size; three parameters that constrain contrast sensitivity. Further, individual differences in performance fields measurements have not been assessed. Here, we use an orientation discrimination task to characterize the pattern of contrast sensitivity across four isoeccentric locations along the cardinal meridians, and to examine whether and how this asymmetry pattern changes with systematic manipulation of stimulus spatial frequency (4 cpd to 8 cpd), eccentricity (4.5° to 9°), and size (3° visual angle to 6° visual angle). Our data demonstrate that contrast sensitivity is highest along the horizontal, intermediate along the lower vertical, and poorest along the upper vertical meridian. This pattern is consistent across stimulus parameter manipulations, even though they cause profound shifts in contrast sensitivity. Eccentricity-dependent decreases in contrast sensitivity can be compensated for by scaling stimulus size alone. Moreover, we find that individual variability in the strength of performance field asymmetries is consistent across conditions. This study is the first to systematically and jointly manipulate, and compare, contrast performance fields across spatial frequency, eccentricity, and size, and to address individual variability in performance fields.

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Section: Eccentricity-dependent Decreases In Contrast Sensitivity At supporting

confidence: 82%

Stimulus-dependent contrast sensitivity asymmetries around the visual field

Himmelberg

Winawer

Carrasco

2020

Preprint

Self Cite

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“…Here we measured lamina-resolved fMRI responses from human participants as they viewed visual stimuli and were required to attend to a specific stimulus feature (orientation). Our stimulus paradigm was designed to elicit concurrent bottom-up and top-down modulations of the stimulus-driven response through orthogonal manipulations of stimulus contrast (bottom-up) and feature-based attention (top-down), both of which are known to influence early visual cortex responses (Boynton et al, 1999; Himmelberg & Wade, 2019; Kamitani & Tong, 2005; Martinez-Trujillo & Treue, 2004; Saenz, Buracas, & Boynton, 2002; Treue & Martinez Trujillo, 1999).…”

Section: Introductionmentioning

confidence: 99%

Dissociable laminar profiles of concurrent bottom-up and top-down modulation in the human visual cortex

Lawrence

Norris

Lange

2018

Preprint

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Recent developments in human neuroimaging make it possible to non-invasively measure neural activity from different cortical layers. This can potentially reveal not only which brain areas are engaged by a task, but also how. Specifically, bottom-up and top-down responses are associated with distinct laminar profiles. Here, we measured lamina-resolved fMRI responses during a visual task designed to induce concurrent bottom-up and top-down modulations via orthogonal manipulations of stimulus contrast and feature-based attention. BOLD responses were modulated by both stimulus contrast (bottom-up) and by engaging feature-based attention (top-down). Crucially, these effects operated at different cortical depths: Bottom-up modulations were strongest in the middle cortical layer, while top-down modulations were strong at all depths, being significantly stronger in deep and superficial layers compared to bottom-up effects. As such, we demonstrate that laminar activity profiles can discriminate between concurrent top-down and bottom-up processing, and are diagnostic of how a brain region is activated.

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“…Two-channel models are frequently used to account for different outcomes based on stimulus features, such as motion speed (Bullier & Nowak, 1995;Himmelberg & Wade, 2019;Stone, Dreher, & Leventhal, 1979). For example, a two-channel model was used to characterize the differences in fMRI-measured responses to changes in luminance (Horiguchi, Nakadomari, Misaki, & Wandell, 2009).…”

Section: Discussionmentioning

confidence: 99%

Center-surround velocity-based segmentation: Speed, eccentricity, and timing of visual stimuli interact to determine interocular dominance

2019

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We used a novel method to capture the spatial dominance pattern of competing motion fields at rivalry onset. When rivaling velocities were different, the participants reported center-surround segmentation: The slower stimuli often dominated in the center while faster motion persisted along the borders. The size of the central static/slow field scaled with the stimulus size. The central dominance was time-locked to the static stimulus onset but was disrupted if the dynamic stimulus was presented later. We then used the same stimuli as masks in an interocular suppression paradigm. The local suppression strengths were probed with targets at different eccentricities. Consistent with the centersurround segmentation, target speed and location interacted with mask velocities. Specifically, suppression power of the slower masks was nonhomogenous with eccentricity, providing a potential explanation for centersurround velocity-based segmentation. This interaction of speed, eccentricity, and timing has implications for motion processing and interocular suppression. The influence of different masks on which target features get suppressed predicts that some ''unconscious effects'' are not generalizable across masks and, thus, need to be replicated under various masking conditions.

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Eccentricity-dependent temporal contrast tuning in human visual cortex measured with fMRI

Cited by 33 publications

References 59 publications

Stimulus-dependent contrast sensitivity asymmetries around the visual field

Stimulus-dependent contrast sensitivity asymmetries around the visual field

Dissociable laminar profiles of concurrent bottom-up and top-down modulation in the human visual cortex

Center-surround velocity-based segmentation: Speed, eccentricity, and timing of visual stimuli interact to determine interocular dominance

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