scholarly journals Investigating mechanisms of fast BOLD responses: the effects of stimulus intensity and of spatial heterogeneity of hemodynamics

NeuroImage ◽  
2021 ◽  
pp. 118658
Author(s):  
Jingyuan E. Chen ◽  
Gary H. Glover ◽  
Nina E. Fultz ◽  
Bruce R. Rosen ◽  
Jonathan R. Polimeni ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Stimulus Intensity ◽  
Bold Responses

Reflex Responses in Upper Limb Muscles to Cutaneous Stimuli

1993 ◽  
Vol 20 (04) ◽  
pp. 271-278 ◽  
Author(s):  
R. Chen
Keyword(s):  
Stimulus Intensity ◽  
Upper Limb ◽  
Healthy Subjects ◽  
Voluntary Contraction ◽  
Cutaneous Reflexes ◽  
Focal Lesions ◽  
Normal Ranges ◽  
Conduction Velocities ◽  
Limb Muscles ◽  
Biphasic Responses

ABSTRACT:Cutaneous reflexes in the upper limb were elicited by stimulating digital nerves and recorded by averaging rectified EMG from proximal and distal upper limb muscles during voluntary contraction. Distal muscles often showed a triphasic response: an inhibition with onset about 50 ms (Il) followed by a facilitation with onset about 60 ms (E2) followed by another inhibition with onset about 80 ms (12). Proximal muscles generally showed biphasic responses beginning with facilitation or inhibition with onset at about 40 ms. Normal ranges for the amplitude of these components were established from recordings on 22 arms of 11 healthy subjects. An attempt was made to determine the alterent fibers responsible for the various components by varying the stimulus intensity, by causing ischemic block of larger fibers and by estimating the afferent conduction velocities. The central pathways mediating these reflexes were examined by estimating central delays and by studying patients with focal lesions

Reduced stimulus intensity as a CS in GSR conditioning.

1967 ◽  
Vol 73 (4, Pt.1) ◽  
pp. 631-632 ◽  
Author(s):  
R. A. Champion
Keyword(s):  
Stimulus Intensity

Soil Spatial Heterogeneity and Systems of Agriculture

2015 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
V. Medvedev
Keyword(s):  
Spatial Heterogeneity ◽  
Soil Cover ◽  
Regular Grid ◽  
Resource Saving ◽  
The Third ◽  
Soil Spatial Heterogeneity ◽  
Agriculture Systems ◽  
Zonal Soils

Aim. To consider soil continuality and discreteness as features of heterogeneity manifestation in a soil cover, important for construction of agriculture systems. Methods. Geostatistical research of soil spatial heterogeneity, revealing the contours of a fi eld with various parameters of fertility. Results. The use of principles of precise agriculture and inspection of indicative properties of fi eld soils using a regular grid allowed to divide a fi eld into contours with three levels of fertility: the fi rst one is characterized by optimal or close to optimum properties which allows refusing from (or reducing substantially) tillage, introduction of fertilizers or chemical ameliorates; the second one has average parameters of fertility corresponding to zonal soils and demands the application of zonal technologies; the third one (with the worst parameters of fertility) presupposes regular use of the improved technologies. Conclusions. The introduction of precise agriculture will allow replacing a traditional zonal system with thenew which is soil-protecting and resource-saving one.

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