scholarly journals Topographic Connectivity in a Duration Selective Cortico-Cerebellar Network

2020 ◽  
Author(s):  
Foteini Protopapa ◽  
Masamichi J. Hayashi ◽  
Ryota Kanai ◽  
Domenica Bueti

AbstractHow does the human brain represent millisecond unit of time? A recent neuroimaging study revealed the existence in the human premotor cortex of a topographic representation of time i.e., neuronal units selectively responsive to specific durations and topographically organized on the cortical surface. By using high resolution functional Magnetic Resonance Images here, we go futher this previous work, showing duration preferences across a wide network of cortical and subcortical brain areas: from cerebellum to primary visual, parietal, premotor and prefrontal cortices. Most importantly, we identify the functional connectivity structure between these different brain areas and their duration selective neural units. The results highlight the role of the cerebellum as the network hub and that of medial premotor cortex as the final stage of duration recognition. Interstingly, when a specific duration is presented, only the communication between the units selective to that duration become particularly “active”. These findings identify duration tuning and topographic connectivity as possible mechanisms underlying our capacity of telling time.

Author(s):  
Alan P. Koretsky ◽  
Afonso Costa e Silva ◽  
Yi-Jen Lin

Magnetic resonance imaging (MRI) has become established as an important imaging modality for the clinical management of disease. This is primarily due to the great tissue contrast inherent in magnetic resonance images of normal and diseased organs. Due to the wide availability of high field magnets and the ability to generate large and rapidly switched magnetic field gradients there is growing interest in applying high resolution MRI to obtain microscopic information. This symposium on MRI microscopy highlights new developments that are leading to increased resolution. The application of high resolution MRI to significant problems in developmental biology and cancer biology will illustrate the potential of these techniques.In combination with a growing interest in obtaining high resolution MRI there is also a growing interest in obtaining functional information from MRI. The great success of MRI in clinical applications is due to the inherent contrast obtained from different tissues leading to anatomical information.


1995 ◽  
Vol 3 (3) ◽  
pp. 236-244 ◽  
Author(s):  
Henning Boecker ◽  
Darius Khorram-Sefat ◽  
Andreas Kleinschmidt ◽  
Klaus-Dietmar Merboldt ◽  
Wolfgnag Hänicke ◽  
...  

1996 ◽  
Vol 6 (2) ◽  
pp. 367-377 ◽  
Author(s):  
Kui Ying ◽  
Bradley D. Clymer ◽  
Petra Schmalbrock

2018 ◽  
Vol 30 (8) ◽  
pp. 1170-1184 ◽  
Author(s):  
Nicolas J. Bourguignon ◽  
Senne Braem ◽  
Egbert Hartstra ◽  
Jan De Houwer ◽  
Marcel Brass

Verbal instructions are central to humans' capacity to learn new behaviors with minimal training, but the neurocognitive mechanisms involved in verbally instructed behaviors remain puzzling. Recent functional magnetic resonance imaging (fMRI) evidence suggests that the right middle frontal gyrus and dorsal premotor cortex (rMFG-dPMC) supports the translation of symbolic stimulus–response mappings into sensorimotor representations. Here, we set out to (1) replicate this finding, (2) investigate whether this region's involvement is specific to novel (vs. trained) instructions, and (3) study whether rMFG-dPMC also shows differences in its (voxel) pattern response indicative of general cognitive processes of instruction implementation. Participants were shown instructions, which they either had to perform later or merely memorize. Orthogonal to this manipulation, the instructions were either entirely novel or had been trained before the fMRI session. Results replicate higher rMFG-dPMC activation levels during instruction implementation versus memorization and show how this difference is restricted to novel, but not trained, instruction presentations. Pattern similarity analyses at the voxel level further reveal more consistent neural pattern responses in rMFG-dPMC during the implementation of novel versus trained instructions. In fact, this more consistent neural pattern response seemed to be specific to the first instruction presentation and disappeared after the instruction had been applied once. These results further support a role of rMFG-dPMC in the implementation of novel task instructions and highlight potentially important differences in studying this region's gross activation levels versus (the consistency of) its response patterns.


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