The HCP 7T Retinotopy Dataset: Description and pRF Analysis

Abstract

About a quarter of human cerebral cortex is tiled with maps of the visual field. These maps can be 3 measured with functional magnetic resonance imaging (fMRI) while subjects view spatially modulated 4 visual stimuli, also known as 'retinotopic mapping'. One of the datasets collected by the Human 5Connectome Project (HCP) involved ultra-high-field (7 Tesla) fMRI retinotopic mapping in 181 healthy 6 adults (1.6-mm resolution), yielding the largest freely available collection of retinotopy data. Here, we 7 describe the experimental paradigm and the results of model-based analysis of the fMRI data. These 8 results provide estimates of population receptive field position and size. Our analyses include both results 9 from individual subjects as well as results obtained by averaging fMRI time-series across subjects at each 10 cortical and subcortical location and then fitting models. Both the group-average and individual-subject 11 results reveal robust signals across much of the brain, including occipital, temporal, parietal, and frontal 12 cortex as well as subcortical areas. The group-average results agree well with previously published 13 parcellations of visual areas. In addition, split-half analyses demonstrate strong within-subject reliability, 14 further evidencing the high quality of the data. We make publicly available the analysis results for 15 individual subjects and the group average, as well as associated stimuli and analysis code. These 16 resources provide an opportunity for studying fine-scale individual variability in cortical and subcortical 17 organization and the properties of high-resolution fMRI. In addition, they provide a measure that can be 18 combined with other HCP measures acquired in these same participants. This enables comparisons 19 across groups, health, and age, and comparison of organization derived from a retinotopic task against 20 that derived from other measurements such as diffusion imaging and resting-state functional connectivity. 21 22. CC-BY 4.0 International license It is made available under a (which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint . http://dx.doi.org/10.1101/308247 doi: bioRxiv preprint first posted online Apr. 25, 2018; 3 Introduction 1 2The central nervous system maps sensory inputs onto topographically organized representations. In the 3 field of vision, researchers have successfully exploited functional magnetic resonance imaging (fMRI) to 4 noninvasively measure visual field representations ('retinotopy') in the living human brain (Engel et al., 5 1994;Sereno et al., 1995; DeYoe et al., 1996; Engel et al., 1997). These efforts enable parcellation of 6 visual cortex into distinct maps of the visual field, thereby laying the foundation for detailed investigations 7 of the properties of visual cortex (parcellation references: Abdollahi et al., 2014;Benson et al., 2014; 8 Wang et al., 2015; review references: Tootell et al., 1996;Wandell et...

Unifying Temporal Phenomena in Human Visual Cortex

“…The increase in temporal window length was systematic but small, increasing by about 30% from V1 to the anterior maps just beyond V3. Qualitatively, this is similar to the increase in spatial receptive field size across the cortical hierarchy, but the differences in spatial receptive fields are larger: receptive field size more than doubles from V1 to V3, and increases by at least 4 times from V1 to V4, measured with either single units (32)(33)(34)(35) or fMRI (20,36,37). Other studies have also found a hierarchy of temporal processing human and macaque cortex.…”

Bayesian Analysis of Retinotopic Maps

“…The prior map, used for methods 2 and 3, was derived from fitting a template to a high-quality dataset derived from 181 subjects in the Human Connectome Project [37][38][39].…”

“…individual brains. Our new method, combined with large datasets such as the HCP retinotopy data set [39], could be used to address this question.…”

“…Each subject participated in 12 retinotopic mapping scans using the same stimulus emptied in the Human Connectome Proect [39]. Briefly, bar apertures on a uniform gray background swept gradually across the visual field at four evenly-spaced orientations while the subject maintained fixation.…”

“…Group-average retinotopic maps (Fig. S2B) were obtained from 181 subjects whose data were published and made freely available as part of the Human Connectome Project [39]. The resulting group-average retinotopic maps are shown in Figure S2B.…”