In vivo functional localization of the temporal monocular crescent representation in human primary visual cortex

Nasr, Shahin; LaPierre, Cristen; Vaughn, Christopher E; Witzel, Thomas; Stockmann, Jason P.; Polimeni, Jon̈athan R.

doi:10.1016/j.neuroimage.2020.116516

Cited by 5 publications

(5 citation statements)

References 51 publications

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“…Notably, this cortical region represents the inferonasal visual field occluded by the head coil resulting in monocular representation by the other eye. Also as expected, we did not detect representation of the blind spot and/or temporal monocular crescent, because these regions are represented more peripherally (r>15°) outside the stimulus borders and scan coverage (Tootell et al, 1998; Awater et al, 2005; Adams et al, 2007; Nasr et al, 2020).…”

Section: Resultssupporting

confidence: 77%

Using high-resolution functional MRI to differentiate impacts of strabismic and anisometropic amblyopia on evoked ocular dominance activity in humans

Nasr,

Skerswetat,

Gaier

et al. 2024

Preprint

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We employed high-resolution functional MRI (fMRI) to distinguish the impacts of anisometropia and strabismus (the two most frequent causes of amblyopia) on the evoked ocular dominance (OD) response. Sixteen amblyopic participants (8 females), comprising 8 individuals with strabismus, 7 with anisometropia, 1 with deprivational amblyopia, along with 8 individuals with normal visual acuity (1 female), participated in this study for whom, we measured the difference between the response to stimulation of the two eyes, across early visual areas (V1–V4). In controls, as expected from the organization of OD columns, the evoked OD response formed a striped pattern that was mostly confined to V1. Compared to controls, the OD response in amblyopic participants formed larger fused patches that extended into downstream visual areas. Moreover, both anisometropic and strabismic participants showed stronger OD responses in V1, as well as in downstream visual areas V2–V4. Although this increase was most pronounced in V1, the correlation between the OD response level and the interocular visual acuity difference (measured behaviorally) was stronger in higher–level visual areas (V2–V4). Beyond these common effects, and despite similar densities of amblyopia between the anisometropic and strabismic participants, we found a greater increase in the size of V1 portion that responded preferentially to fellow eye stimulation in anisometropic compared to strabismic individuals. We also found a greater difference between the amplitudes of the response to binocular stimulation, in those regions that responded preferentially to the fellow vs. amblyopic eye, in anisometropic compared to strabismic subjects. In contrast, strabismic subjects demonstrated increased correlation between the OD responses evoked within V1 superficial and deep cortical depths, whereas anisometropic subjects did not. These results provide some of the first direct functional evidence for distinct impacts of strabismus and anisometropia on the mesoscale functional organization of the human visual system, thus extending what was inferred previously about amblyopia from animal models.

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Section: Resultssupporting

confidence: 77%

Using high-resolution functional MRI to differentiate impacts of strabismic and anisometropic amblyopia on evoked ocular dominance activity in humans

Nasr,

Skerswetat,

Gaier

et al. 2024

Preprint

Self Cite

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show abstract

“…The interpretation of the laminar profile is built on the assumption that the monocular feedforward information is exploited in V1, which is encoded at the fine-grained level of ODCs. Note that the larger monocular regions in V1, like the blind spot (Tootell, Hadjikhani, et al, 1998) and the temporal monocular crescent (Nasr, LaPierre, et al, 2020), were not covered in our experiment due to the limited field of view. However, we cannot exclude that other features besides ocularity might have contributed to the successful eye-of-origin decoding.…”

Section: Discussionmentioning

confidence: 95%

Decoding of columnar-level organization across cortical depth using BOLD- and CBV-fMRI at 7 T

Haenelt,

Chaimow,

Nasr

et al. 2023

Preprint

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Multivariate pattern analysis (MVPA) methods are a versatile tool to retrieve information from neurophysiological data obtained with functional magnetic resonance imaging (fMRI) techniques. Since fMRI is based on measuring the hemodynamic response following neural activation, the spatial specificity of the fMRI signal is inherently limited by contributions of macrovascular compartments that drain the signal from the actual location of neural activation, making it challenging to image cortical structures at the spatial scale of cortical columns and layers. By relying on information from multiple voxels, MVPA has shown promising results in retrieving information encoded in fine-grained spatial patterns. We examined the spatial specificity of the signal exploited by MVPA. Over multiple sessions, we measured ocular dominance columns (ODCs) in human primary visual cortex (V1) with different acquisition techniques at 7 T. For measurements with blood oxygenation level dependent contrast (BOLD), we included both gradient echo- (GE-BOLD) and spin echo-based (SE-BOLD) sequences. Furthermore, we acquired data using the vascular-space-occupancy (VASO) fMRI technique, which is sensitive to cerebral blood volume (CBV) changes. We used the data to decode the eye-of-origin across cortical depth. While ocularity information can be decoded with all imaging techniques, the macrovascular contributions in GE- and SE-BOLD limit their use for discriminating signals between cortical layers. However, the cortical profile of decoded ocularity information from VASO measurements better reflects the expected profile of neural activity, suggesting the combination of VASO and MVPA to be a promising approach for investigating the mesoscopic circuitry of the human cerebral cortex.

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“…In these setups, a small screen was positioned very close to the eyes (3 cm), and participants had to wear a contact lens to get help with focus and fixation at such a short distance. And, most recently, stimulation of the entire visual field was achieved 60 . Using custom-built goggles with white light-emitting diodes (LEDs), they were able to functionally localize the temporal monocular crescent, which requires wide-angle projection beyond 120 deg.…”

Section: Discussionmentioning

confidence: 99%

Immersive scene representation in human visual cortex with ultra-wide-angle neuroimaging

Park,

Soucy,

Segawa

et al. 2024

Nat Commun

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While human vision spans 220°, traditional functional MRI setups display images only up to central 10-15°. Thus, it remains unknown how the brain represents a scene perceived across the full visual field. Here, we introduce a method for ultra-wide angle display and probe signatures of immersive scene representation. An unobstructed view of 175° is achieved by bouncing the projected image off angled-mirrors onto a custom-built curved screen. To avoid perceptual distortion, scenes are created with wide field-of-view from custom virtual environments. We find that immersive scene representation drives medial cortex with far-peripheral preferences, but shows minimal modulation in classic scene regions. Further, scene and face-selective regions maintain their content preferences even with extreme far-periphery stimulation, highlighting that not all far-peripheral information is automatically integrated into scene regions computations. This work provides clarifying evidence on content vs. peripheral preferences in scene representation and opens new avenues to research immersive vision.

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In vivo functional localization of the temporal monocular crescent representation in human primary visual cortex

Cited by 5 publications

References 51 publications

Using high-resolution functional MRI to differentiate impacts of strabismic and anisometropic amblyopia on evoked ocular dominance activity in humans

Using high-resolution functional MRI to differentiate impacts of strabismic and anisometropic amblyopia on evoked ocular dominance activity in humans

Decoding of columnar-level organization across cortical depth using BOLD- and CBV-fMRI at 7 T

Immersive scene representation in human visual cortex with ultra-wide-angle neuroimaging

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