Activation sequence of discrete brain areas during cognitive processes: results from magnetic field tomography

1994 ◽  
Vol 91 (5) ◽  
pp. 399-402 ◽  
Author(s):  
A.A. Ioannides ◽  
P.B.C. Fenwick ◽  
J. Lumsden ◽  
M.J. Liu ◽  
P.D. Bamidis ◽  
...  
Biomag 96 ◽  
2000 ◽  
pp. 257-260
Author(s):  
A. A. Ioannides ◽  
J. P. R. Bolton ◽  
M. J. Liu ◽  
P. D. Bamidis ◽  
L. C. Liu ◽  
...  

2010 ◽  
Vol 4 (3) ◽  
pp. 181-187 ◽  
Author(s):  
Kellen Christina Malheiros Borges ◽  
Jussara Rocha Ferreira ◽  
Leonardo Ferreira Caixeta

Abstract The organization of the prefrontal cortex can hold important clues to understanding its functioning. The Cebus apella present cerebral particularities and behavioral and cognitive flexibility, possessing abilities that demonstrate an overlap with those of big primates. Objectives: To provide evidence of correlations between anatomical particularities of the brain areas analyzed and some cognitive abilities previously described in these simians. Methods: The relative size of the cerebral hemispheres and prefrontal areas (PFA) were measured using a Universal caliper, in 24 hemispheres of C. apella fixed with 10% formaldehyde and kept in 70% alcoholic solution. Results: Data gathered allowed the calculation of the approximate volume (cm3) of the areas under study: right antimere 35.2 cm3 (±5.3), left antimere 31.3 cm3 (±5.4) and of the left PFA 6.0 cm3 (±1.5) and right PFA 6.9 cm3 (±1.7). Conclusions: We concluded that the PFA represents about 20% of the cerebral volume of this primate. No significant differences were found in the antimeres in terms of volume and area of the hemispheres and likewise for the PFA. These animals have a proportionally bigger brain than that of other neotropical primates in the literature. This allows us to infer that the frontal lobe of C. apella is also larger; possibly related to its maturity and developed cognitive functions indicative of the culture transfers characteristic of this species.


Author(s):  
Zafiris J. Daskalakis ◽  
Robert Chen

Transcranial magnetic stimulation was first introduced in the late 1980s. Numerous studies have used TMS as an investigational tool to elucidate cortical physiology and to probe cognitive processes. This article introduces TMS paradigms and presents information gathered on cortical neuronal connectivity. TMS paradigms that demonstrate intracortical inhibition include short-interval cortical inhibition (SICI), cortical silence period (cSP) and long interval cortical inhibition (LICI). There are two types of cortical inhibitions from the stimulation of other brain areas, interhemispheric inhibition and cerebellum inhibition. The inhibition of the motor cortex can also be induced through the stimulation of peripheral nerves. This article talks about studies that describe interaction between inhibitory and facilitatory paradigms, the results of which are discussed in terms of cortical physiology and connectivity. The study of the interactions among cortical inhibitory and excitatory circuits may help to elucidate pathophysiology of neurological and psychiatric diseases.


2011 ◽  
Vol 402 ◽  
pp. 326-330
Author(s):  
Shou Qiang Men ◽  
Hong Bo Xiao ◽  
Christian Resagk

Magnetic field tomography was applied to reconstruct the oscillating interface between liquid GaInSn alloy and aqueous KOH solution in a simplified cylindrical aluminum reduction cell. A direct electric current was imposed similar to the industrial reduction procedure, and a pneumatic shaker was used to excite interfacial instabilities with non-axisymmetric interface modes at the same time. The deformed interface led to a perturbation to the magnetic field which was measured by a sensor array. By fast Fourier Transforms, a database was generated and exploited to reconstruct the interface oscillation by solving an inverse problem.


NeuroImage ◽  
1998 ◽  
Vol 7 (4) ◽  
pp. S760
Author(s):  
A.A. Ioannides ◽  
J.G. Taylor ◽  
N.J. Shah ◽  
L.C. Liu ◽  
J.D. Dammers ◽  
...  

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