168 research outputs found
A new hybrid iteration method for a finite family of asymptotically nonexpansive mappings in Banach spaces
Strong convergence theorems for two total asymptotically nonexpansive nonself mappings in Banach spaces
On the convergence of hybrid projection algorithms for total quasi-asymptotically pseudo-contractive mapping
Convergence analysis of a general iteration schema of nonlinear mappings in hyperbolic spaces
Strong convergence theorems for asymptotically nonexpansive nonself-mappings with applications
Feedforward and feedback pathways of nociceptive and tactile processing in human somatosensory system: A study of dynamic causal modeling of fMRI data
Nociceptive and tactile information is processed in the somatosensory system via reciprocal (i.e., feedforward and feedback) projections between the thalamus, the primary (S1) and secondary (S2) somatosensory cortices. The exact hierarchy of nociceptive and tactile information processing within this ‘thalamus-S1-S2’ network and whether the processing hierarchy differs between the two somatosensory submodalities remains unclear. In particular, two questions related to the ascending and descending pathways have not been addressed. For the ascending pathways, whether tactile or nociceptive information is processed in parallel (i.e., 'thalamus-S1′ and 'thalamus-S2′) or in serial (i.e., 'thalamus-S1-S2′) remains controversial. For the descending pathways, how corticothalamic feedback regulates nociceptive and tactile processing also remains elusive. Here, we aimed to investigate the hierarchical organization for the processing of nociceptive and tactile information in the ‘thalamus-S1-S2’ network using dynamic causal modeling (DCM) combined with high-temporal-resolution fMRI. We found that, for both nociceptive and tactile information processing, both S1 and S2 received inputs from thalamus, indicating a parallel structure of ascending pathways for nociceptive and tactile information processing. Furthermore, we observed distinct corticothalamic feedback regulations from S1 and S2, showing that S1 generally exerts inhibitory feedback regulation independent of external stimulation whereas S2 provides additional inhibition to the thalamic activity during nociceptive and tactile information processing in humans. These findings revealed that nociceptive and tactile information processing have similar hierarchical organization within the somatosensory system in the human brain
Dinâmica do potencial matricial em substratos de pinus e coco sob ação da capilaridade
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