scholarly journals Correlational Imaging of Thalamocortical Coupling in the Primary Visual Pathway of the Human Brain

1994 ◽  
Vol 14 (6) ◽  
pp. 952-957 ◽  
Author(s):  
Andreas Kleinschmidt ◽  
Klaus-Dietmar Merboldt ◽  
Wolfgang Hänicke ◽  
Helmuth Steinmetz ◽  
Jens Frahm

While the anatomy of the human brain is well defined, the functional connectivity of its structures is far less understood. Modern neuroimaging techniques offer the unique opportunity of visualizing physiologic activation in central nervous structures and of identifying the elements underlying distributed networks for information processing. Following improved spatial resolution of deoxyhemoglobin-sensitive magnetic resonance imaging, we were able to detect simultaneous signal changes in the lateral geniculate nucleus and primary visual cortex during periodic photic stimulation. Visualization of coupled activation by cross-correlation analysis resulted in the first demonstration of thalamocortical interaction in the primary visual pathway of the intact human brain.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luca Vizioli ◽  
Steen Moeller ◽  
Logan Dowdle ◽  
Mehmet Akçakaya ◽  
Federico De Martino ◽  
...  

AbstractFunctional magnetic resonance imaging (fMRI) has become an indispensable tool for investigating the human brain. However, the inherently poor signal-to-noise-ratio (SNR) of the fMRI measurement represents a major barrier to expanding its spatiotemporal scale as well as its utility and ultimate impact. Here we introduce a denoising technique that selectively suppresses the thermal noise contribution to the fMRI experiment. Using 7-Tesla, high-resolution human brain data, we demonstrate improvements in key metrics of functional mapping (temporal-SNR, the detection and reproducibility of stimulus-induced signal changes, and accuracy of functional maps) while leaving the amplitude of the stimulus-induced signal changes, spatial precision, and functional point-spread-function unaltered. We demonstrate that the method enables the acquisition of ultrahigh resolution (0.5 mm isotropic) functional maps but is also equally beneficial for a large variety of fMRI applications, including supra-millimeter resolution 3- and 7-Tesla data obtained over different cortical regions with different stimulation/task paradigms and acquisition strategies.


1998 ◽  
Vol 163 (1) ◽  
pp. 39-46 ◽  
Author(s):  
A. Sbarbati ◽  
P. Marzola ◽  
A. Simonati ◽  
E. Nicolato ◽  
F. Osculati

Sign in / Sign up

Export Citation Format

Share Document