This post summarized the layer-fMRI abstracts form major relevant conferences 2024, including ISMRM, OHBM. This is following the posts of previous years 2023, 2022, 2021, 2020, 2019.

OHBM, Seoul, Korea June 23 – 27

Abstract search tool by OHBM is here.

0963 – Laminar profiles of hippocampal subfields are differentially associated with navigation strategies, Khazar Ahmadi, Department of Neuropsychology, Institute of Cognitive Neuroscience, Ruhr University Bochum, Germany
1101 – Ultrafast resting state fMRI unveils layer-specific feedforward and feedback interactions, Joana Carvalho, Champalimaud Foundation, Lisbon
1284 – 7T BOLD fMRI charactersiation of depth dependent hemodynamics in developing human cortex, Jucha Willers Moore, King’s College London, United Kingdom
1348 – Ultrafast fMRI Reveals Laminar Specificity of Hemodynamic Profiles in Primary Somatosensory Cortex, Xiangnan Tian, ShanghaiTech University, Shanghai, China
1137 – A layer-specific model of cortical sensory aging, Peng Liu, Hertie Institute for Clinical Brain Research (HIH)), Tübingen, Germany
1643 – Inferring laminar origins of MEG signals with optically pumped magnetometers (OPMs), Saskia Helbling, Ernst Strungmann Institute for Neuroscience, Frankfurt am Main, Germany, Novel Imaging Acquisition Methods, Thursday, June 27, 2024: 11:30 AM – 12:45 PM, COEX, Room: Hall D 2
1842 – Automatic, whole-brain segmentation of cortical layers for the high-resolution anatomical data at 7T, Roman Belenya, Klinikum rechts der Isar, Technical University of Munich, Bavaria
1881 – Acquisition and evaluation of sub-millimetre resolution GE-BOLD laminar fMRI datasets at 3T and 7 T, Sriranga Kashyap, Krembil Brain Institute, University Health Network, Toronto, Canada
1922 – A new contrast “phase jolt” for analysis of phase-data fMRI reveals strong task-related responses, Omer Faruk Gulban, Maastricht University, Netherlands
2007 – VesselBoost: Improving Segmentation of Small Vessels in Human Brain Magnetic Resonance Angiograms, Marshall Xu, School of Electrical Engineering and Computer Science, The University of Queensland, Australia
2120 – Quantifying human infra- and supra-granular layer properties using high-resolution ex vivo MRI, Oula Puonti, Danish Research Centre for Magnetic Resonance, Hvidovre
2163 – Mesoscopic functional connectivity between cortex and globus pallidus nuclei, Vinod Kumar, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
2323 – Layer-specific fMRI of the human hippocampus in autobiographical memory, Viktor Pfaffenrot, Erwin L. Hahn Institute for Magnetic Resonance Imaging, University of Duisburg-Essen, Germany
2343 – Differences in layered activation of the insula during interoceptive vs. exteroceptive attention, Matthias Müller-Schrader, Translational Neuromodeling Unit (TNU), University of Zurich & ETH Zurich
2433 – Ultra-high-field fMRI mapping of layer-specific somatosensory processing in marmoset brain, Jiajia Yang, Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan
2435 – Multi-scale brain function of tactile prediction processing: from cortical layers to whole brain, Yinghua Yu, Faculty of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan
2482 – Attention Reshapes Receptive Fields for Thermal and Tactile Perception, Dongho Kim, Center for Neuroscience Imaging Research, IBS, Suwon-Si, Gyeonggi
2534 – Cortical Representations of Vibrotactile Stimuli with Varying Frequency in Human S1, Ji-Hyun Kim, UNIST, Ulsan
2535 – Identifying cortical columns for slow/rapid vibrotactile stimulation in human S1 using 7T fMRI. Ashley York, Centre for Advanced Imaging, University of Queensland, Brisbane, Queenslan
2540 – Whole brain and primary visual cortex layer fMRI signatures of afterimage perception, Sharif Kronemer, National Institute of Mental Health, Bethesda
2541 – Characterizing individual top-down depth-dependent human microcircuitry in ventro-temporal cortex, Luca Vizioli, CMRR, MN
2550 – Top-down vs bottom-up origins of sensory uncertainty in early visual cortex, Joshua Corbett, University of Melbourne, Melbourne, Australia
2552 – Cortical depth-based variation of population receptive field size in human V1, V2 and V3, Maya Jastrzębowska, Freie Universität Berlin
2554 – Feedback and feedforward laminar modulation of human motion perception: a 7T fMRI study, Alessandra Pizzuti, Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Netherland
2557 – A 7T fMRI correlate of visual perceptual filling-in in human visual cortex. Kenshu Koiso, Univeristy Maastricht.
2559 – The cortical microcircuitry of contextual processing in mice, monkeys, and humans, Lars Muckli, Univeristy of Glasgow

VSS May 17th-22nd, St. Pete Beach, Florida

Talk: 7T CBV FMRI REVEALS CORTICAL MICROCIRCUITS OF BOTTOM-UP SALIENCY IN THE HUMAN BRAIN, Peng Zhang , Chinese Academy of Sciences

Poster: FEEDBACK TO V1 STRONGLY INFLUENCES BOLD SIGNAL DURING CONTEXTUAL MODULATION: EVIDENCE FROM LAMINAR FMRI
Joseph Emerson, CMRR, POSTER PDF

Human visual perception relies on contextual information to make inferences about spatially localized features in visual scenes. Similarly, neural representations of local features in primary visual cortex (V1) are shaped by broad spatial context through long-range lateral connections and feedback from higher-order visual areas. However, it is unclear exactly how and to what extent lateral and feedback connectivity individually contribute to contextual modulation of neural responses in V1. Ultra-high-field fMRI have enabled noninvasive imaging of cortical layers in humans, which can be exploited to examine the cortical origins of neural signals underlying blood oxygenation-level-dependent (BOLD) contrast. We analyzed data from five participants using 7T fMRI at 0.6 mm isotropic resolution to measure the influence of visual context on BOLD response profiles across cortical depth in V1. Participants viewed sine-wave grating disks embedded in large surround gratings with matched spatial frequency and contrast. Segmentation cues were provided by either an offset in relative orientation or an offset in relative phase between target and surround gratings for a total of three contextual conditions plus a surround-only condition to measure the effects of cortical feedback in the absence of feedforward input. Our analysis isolated the effects of orientation-tuned surround suppression (OTSS) from figure-ground modulation (FGM). Consistent with contextually-driven responses measured in mice and monkeys, we found significant modulation of BOLD signal in target-selective voxels in the absence of feedforward input. While we found strong signatures of FGM in superficial and deep layers, we did not find significant modulation of the BOLD signal due to OTSS. Our results suggest that the mechanisms responsible for OTSS have a weaker impact on the BOLD signal. We conclude that a large proportion of the BOLD signal measured in V1 depends on feedback from higher-order visual cortex, which is reflected in contextually-dependent changes in laminar profiles.

Poster, OPTIMIZED LAYER-SPECIFIC FMRI METHODS TO DISSOCIATE FEEDFORWARD AND FEEDBACK INFORMATION ACROSS LAYERS OF THE VENTRAL VISUAL STREAM
Taylor L. Li, NIMH

Layer-specific fMRI promises to dissociate feedforward and feedback information across cortical laminae from V1 to downstream categoryselective visual regions in ventral occipitotemporal cortex (VOTC). However, using a cutting-edge functional MRI method called vascular space occupancy (VASO) to measure fMRI signals at submillimeter resolution comes with major methodological challenges. Thus, we introduce two methodological advances that allow us to measure layer-specific fMRI signals in VOTC. The first is a forward model that can predict the optimal flip angle regime for the VASO sequence in the brain region to be studied. The second is an anatomical segmentation routine that cleanly segments the cortical ribbon from white matter and cerebral spinal fluid for precise definition of cortical layers. We used this optimized VASO fMRI routine in a study on perceving and imaging faces and places. Participants saw the names of famous faces and places followed by either a picture (perception), or a white frame (mental imagery) during separate task blocks. After independently localizing the fusiform face area and parahippocampal place area, we found preliminary evidence that mental imagery elicits the strongest responses in the superficial and deep layers of the corresponding category-selective region that receive feedback signals from higherorder brain regions but not in the middle layers that receive feedforward signals from early visual cortex. In contrast, viewing pictures of famous faces and places elicits the strongest responses in the middle (and superficial) layers. Thus, our methodological advances allow us to accurately dissociate feedforward and feedback information across layers of VOTC.

Poster CORTICAL DEPTH-DEPENDENT POPULATION RECEPTIVE FIELD SIZE VARIATION IN HUMAN V1, V2 AND V3, Maya Jastrzebowska, Freie Universität Berlin, POSTER PDF

The early visual cortex is organized in accordance with well established principles of retinotopy and cortical magnification. Receptive field (RF) size increases systematically with eccentricity from fovea to periphery and along the visual hierarchy. However, the organization of RFs across cortical depths is not yet well understood. While non-human primate neurophysiology shows RF size variation across cortical laminae, evidence in humans is lacking. Here, we used submillimeter fMRI to map RF properties in vivo at the scale of cortical laminae. We measured gradient-echo blood oxygenation level dependent (BOLD) responses to a drifting bar stimulus using 7 Tesla fMRI and population receptive field (pRF) mapping in four human participants. We projected the fMRI data to eight equivolumetric cortical surfaces based on white matter and pial surface reconstructions. Fitting a pRF model to the BOLD time series of each vertex of each surface, we estimated the location in visual space and pRF size that best explain visual field selectivity. We computed the pRF size at 2 degrees of eccentricity in three early visual regions of interest (ROIs) V1, V2 and V3. For each participant and ROI, we characterized the cortical depth profile of pRF size, as well as the profile of the surround suppression to center excitation ratio (suppression index). We replicate previous findings of a U-shaped relation between pRF size and cortical depth in V1. Moreover, we extend these findings by demonstrating depth-dependent patterns in V2 and V3. Similarly to V1, pRF sizes in V2 are largest in deep layers, followed by superficial and middle layers, with the reverse pattern in V3. The suppression index remains flat across depths, consistent with previous reports. Our findings demonstrate that pRF size variation across cortical depth is robustly quantifiable in humans in vivo, lending support to future examinations of feedforward and feedback mechanisms of spatial vision.