scholarly journals Ultra high-field (7 T) multi-resolution fMRI data for orientation decoding in visual cortex

Data in Brief ◽  
2017 ◽  
Vol 13 ◽  
pp. 219-222
Author(s):  
Ayan Sengupta ◽  
Renat Yakupov ◽  
Oliver Speck ◽  
Stefan Pollmann ◽  
Michael Hanke
2019 ◽  
Author(s):  
Ingo Marquardt ◽  
Peter De Weerd ◽  
Marian Schneider ◽  
Omer Faruk Gulban ◽  
Dimo Ivanov ◽  
...  

AbstractHuman visual surface perception has neural correlates in early visual cortex, but the extent to which feedback contributes to this activity is not well known. Feedback projections preferentially enter superficial and deep anatomical layers, while avoiding the middle layer, which provides a hypothesis for the cortical depth distribution of fMRI activity related to feedback in early visual cortex. Here, we presented human participants uniform surfaces on a dark, textured background. The grey surface in the left hemifield was either perceived as static or moving based on a manipulation in the right hemifield. Physically, the surface was identical in the left visual hemifield, so any difference in percept likely was related to feedback. Using ultra-high field fMRI, we report the first evidence for a depth distribution of activation in line with feedback during the (illusory) perception of surface motion. Our results fit with a signal re-entering in superficial depths of V1, followed by a feedforward sweep of the re-entered information through V2 and V3, as suggested by activity centred in the middle-depth levels of the latter areas. This positive modulation of the BOLD signal due to illusory surface motion was on top of a strong negative BOLD response in the cortical representation of the surface stimuli, which depended on the presence of texture in the background. Hence, the magnitude and sign of the BOLD response to the surface strongly depended on background properties, and was additionally modulated by the presence or absence of illusory motion perception in a manner compatible with feedback. In summary, the present study demonstrates the potential of depth resolved fMRI in tackling biomechanical questions on perception that so far were only within reach of invasive animal experimentation.


2019 ◽  
Vol 19 (10) ◽  
pp. 186b
Author(s):  
Ke Jia ◽  
Elisa Zamboni ◽  
Nuno Reis Goncalves ◽  
Catarina Rua ◽  
Valentin Kemper ◽  
...  

2020 ◽  
Vol 124 (6) ◽  
pp. 1900-1913
Author(s):  
Justine C. Cléry ◽  
Yuki Hori ◽  
David J. Schaeffer ◽  
Joseph S. Gati ◽  
J. Andrew Pruszynski ◽  
...  

We used somatosensory stimulation combined with functional MRI (fMRI) in awake marmosets to reveal the topographic body representation in areas S1, S2, thalamus, and putamen. We showed the existence of a body representation organization within the thalamus and the cingulate cortex by computing functional connectivity maps from seeds defined in S1/S2 using resting-state fMRI data. This noninvasive approach will be essential for chronic studies by guiding invasive recording and manipulation techniques.


Author(s):  
Gilles de Hollander ◽  
Wietske van der Zwaag ◽  
Chencan Qian ◽  
Peng Zhang ◽  
Tomas Knapen

AbstractUltra-high field MRI can functionally image the cerebral cortex of human subjects at the submillimeter scale of cortical columns and laminae. Here, we investigate both in concert, by, for the first time, imaging ocular dominance columns (ODCs) in primary visual cortex (V1) across different cortical depths. We ensured that putative ODC patterns in V1 (a) are stable across runs, sessions, and scanners located in different continents (b) have a width (∼1.3 mm) expected from post-mortem and animal work and (c) are absent at the retinotopic location of the blind spot. We then dissociated the effects of bottom-up thalamo-cortical input and attentional feedback processes on activity in V1 across cortical depth. Importantly, the separation of bottom-up information flows into ODCs allowed us to validly compare attentional conditions while keeping the stimulus identical throughout the experiment. We find that, when correcting for draining vein effects and using both model-based and model-free approaches, the effect of monocular stimulation is largest at deep and middle cortical depths. Conversely, spatial attention influences BOLD activity exclusively near the pial surface. Our findings show that simultaneous interrogation of columnar and laminar dimensions of the cortical fold can dissociate thalamocortical inputs from top-down processing, and allow the investigation of their interactions without any stimulus manipulation.Significance StatementThe advent of ultra-high field fMRI allows for the study of the human brain non-invasively at submillimeter resolution, bringing the scale of cortical columns and laminae into focus. De Hollander et al imaged the ocular dominance columns and laminae of V1 in concert, while manipulating top-down attention. This allowed them to separate feedforward from feedback processes in the brain itself, without resorting to the manipulation of incoming information. Their results show how feedforward and feedback processes interact in the primary visual cortex, highlighting the different computational roles separate laminae play.


Data in Brief ◽  
2016 ◽  
Vol 7 ◽  
pp. 468-471
Author(s):  
Thomas C. Emmerling ◽  
Jan Zimmermann ◽  
Bettina Sorger ◽  
Martin Frost ◽  
Rainer Goebel

eNeuro ◽  
2019 ◽  
Vol 6 (6) ◽  
pp. ENEURO.0429-19.2019 ◽  
Author(s):  
Ai Koizumi ◽  
Minye Zhan ◽  
Hiroshi Ban ◽  
Ikuhiro Kida ◽  
Federico De Martino ◽  
...  

2018 ◽  
Author(s):  
Ai Koizumi ◽  
Minye Zhan ◽  
Hiroshi Ban ◽  
Ikuhiro Kida ◽  
Federico de Martino ◽  
...  

AbstractThe perceptual system gives priority to threat-relevant signals with survival value. Its mechanism may not only include the processing initiated in the presence of threat signals but also in the mere anticipation of such signals. Here, we show that the pulvinar modulates activity in the early visual cortex (V1) specifically in threat anticipation. Using ultra-high-field 7T fMRI, we examined the layer-specific interaction between V1 and the pulvinar, while taking advantage of the fact that the directionality of such interaction is anatomically constrained in specific V1 layers. Only in anticipation of a fearful face target, but not of a control happy face target, was false perception of anticipated-yet-unpresented target face accompanied by stronger activity in the V1 superficial-cortical-depth (layers 1-3), which was preceded by pre-target-onset pulvinar activity. The pulvinar may contribute to the visual processing initiated in the anticipation of threat, and play an important role in anxiety.


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