Feedback contribution to surface motion perception in the human early visual cortex

Marquardt, Ingo; Weerd, Peter De; Schneider, Marian; Gulban, Omer Faruk; Ivanov, Dimo; Wang, Yawen; Uludağ, Kâmil

doi:10.7554/elife.50933

Cited by 10 publications

(13 citation statements)

References 136 publications

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“…Figure 7, see also Figure S1 in the Supplementary Materials), but in general is expected to have mixed neuronal and vascular origin (Havlicek and Uludağ, 2020). Note that this feature was also not evident in numerous studies using comparable acquisition and analysis techniques (de Hollander et al, 2021;De Martino et al, 2013;Fracasso et al, 2018;Klein et al, 2018;Marquardt et al, 2020;Polimeni et al, 2010).…”

Section: Discussionmentioning

confidence: 89%

Modelling the depth-dependent VASO and BOLD responses in human primary visual cortex

Akbari

Bollmann

et al. 2021

Preprint

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Functional magnetic resonance imaging (fMRI) using blood-oxygenation-level-dependent (BOLD) contrast is a common method for studying human brain function non-invasively. Gradient-echo (GRE) BOLD is highly sensitive to the blood oxygenation change in blood vessels; however, the signal specificity can be degraded due to signal leakage from the activated lower layers to the superficial layers in depth-dependent (also called laminar or layer-specific) fMRI. Alternatively, physiological variables such as cerebral blood volume using VAscular-Space-Occupancy (VASO) measurements have shown higher spatial specificity compared to BOLD. To better understand the physiological mechanisms (e.g., blood volume and oxygenation change) and to interpret the measured depth-dependent responses we need models that reflect vascular properties at this scale. For this purpose, we adapted a cortical vascular model previously developed to predict the layer-specific BOLD signal change in human primary visual cortex to also predict layer-specific VASO response. To evaluate the model, we compared the predictions with experimental results of simultaneous VASO and BOLD measurements in a group of healthy participants. Fitting the model to our experimental findings provided an estimate of CBV change in different vascular compartments upon neural activity. We found that stimulus-evoked CBV changes mainly occur in intracortical arteries as well as small arterioles and capillaries and that the contribution from venules is small for a long stimulus (~30 sec). Our results confirm the notion that VASO contrast is less susceptible to large vessel effects compared to BOLD.

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Section: Discussionmentioning

confidence: 89%

Modelling the depth-dependent VASO and BOLD responses in human primary visual cortex

Akbari

Bollmann

et al. 2021

Preprint

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“…Layer-specific fMRI is a novel technique that has only recently become feasible due to the submillimetre resolution required. It has been successfully used to study many cognitive processes, such as attention [ 34 – 36 ], working memory [ 37 , 38 ], spatial context [ 39 ], perceptual illusions [ 32 , 40 , 41 ], somatosensation [ 17 ], and even language [ 42 ]. Encouragingly, results have generally been in good alignment with those obtained from invasive animal studies [ 43 – 45 ].…”

Section: Resultsmentioning

confidence: 99%

Prior expectations evoke stimulus-specific activity in the deep layers of the primary visual cortex

et al. 2020

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The way we perceive the world is strongly influenced by our expectations. In line with this, much recent research has revealed that prior expectations strongly modulate sensory processing. However, the neural circuitry through which the brain integrates external sensory inputs with internal expectation signals remains unknown. In order to understand the computational architecture of the cortex, we need to investigate the way these signals flow through the cortical layers. This is crucial because the different cortical layers have distinct intra- and interregional connectivity patterns, and therefore determining which layers are involved in a cortical computation can inform us on the sources and targets of these signals. Here, we used ultra-high field (7T) functional magnetic resonance imaging (fMRI) to reveal that prior expectations evoke stimulus-specific activity selectively in the deep layers of the primary visual cortex (V1). These findings are in line with predictive processing theories proposing that neurons in the deep cortical layers represent perceptual hypotheses and thereby shed light on the computational architecture of cortex.

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“…Further, different stimulus conditions evoke variations in the distribution of the BOLD response across cortical depth for visual stimuli [33]. Depth profiles have also been demonstrated in studies investigating somatosensory stimuli [41], working memory [45], language processing [46] and feedback responses in early visual cortex [33,42,47].…”

Section: (B) Separation Of Neural Subpopulations By Laminar Organizationmentioning

confidence: 81%

“…The presence of objectively identifiable landmarks and the functional significance of the GM have led to layer-dependent fMRI becoming an enormously popular subfield in UFH fMRI. Several studies have taken advantage of UFH fMRI capabilities to resolve functional responses at different cortical depths [33,[39][40][41][42][43][44][45][46][47]. Visual stimuli evoke patterns of BOLD response across cortical depth in V1 [39,43] and MT [40].…”

Section: (B) Separation Of Neural Subpopulations By Laminar Organizationmentioning

confidence: 99%

Forging a path to mesoscopic imaging success with ultra-high field functional magnetic resonance imaging

Weldon

Olman

2020

Phil. Trans. R. Soc. B

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Functional magnetic resonance imaging (fMRI) studies with ultra-high field (UHF, 7+ Tesla) technology enable the acquisition of high-resolution images. In this work, we discuss recent achievements in UHF fMRI at the mesoscopic scale, on the order of cortical columns and layers, and examine approaches to addressing common challenges. As researchers push to smaller and smaller voxel sizes, acquisition and analysis decisions have greater potential to degrade spatial accuracy, and UHF fMRI data must be carefully interpreted. We consider the impact of acquisition decisions on the spatial specificity of the MR signal with a representative dataset with 0.8 mm isotropic resolution. We illustrate the trade-offs in contrast with noise ratio and spatial specificity of different acquisition techniques and show that acquisition blurring can increase the effective voxel size by as much as 50% in some dimensions. We further describe how different sources of degradations to spatial resolution in functional data may be characterized. Finally, we emphasize that progress in UHF fMRI depends not only on scientific discovery and technical advancement, but also on informal discussions and documentation of challenges researchers face and overcome in pursuit of their goals. This article is part of the theme issue ‘Key relationships between non-invasive functional neuroimaging and the underlying neuronal activity’.

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Feedback contribution to surface motion perception in the human early visual cortex

Cited by 10 publications

References 136 publications

Modelling the depth-dependent VASO and BOLD responses in human primary visual cortex

Modelling the depth-dependent VASO and BOLD responses in human primary visual cortex

Prior expectations evoke stimulus-specific activity in the deep layers of the primary visual cortex

Forging a path to mesoscopic imaging success with ultra-high field functional magnetic resonance imaging

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