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Oculata Manus
Published in Stephen Temple, Developing Creative Thinking in Beginning Design, 2018
Dr. Karin James, a psychologist at Indiana University, has conducted studies in which she asked children who had not yet learned to read or write to reproduce a letter form or shape presented to them. The children, “were then placed in a brain scanner and shown the image again. The researchers found that the initial duplication process mattered a great deal. When children had drawn a letter freehand, they exhibited increased activity in three areas of the brain that are activated in adults when they read and write: the left fusiform gyrus, the inferior frontal gyrus and the posterior parietal cortex. By contrast, children who typed or traced the letter or shape showed no such effect.” (Konnikova 2014) The role of the hand is significant in the learning process. The differences in neural activity generated by freehand drawing as opposed to tracing or typing was attributed “to the messiness inherent in free-form handwriting: Not only must we first plan and execute the action in a way that is not required when we have a traceable outline, but we are also likely to produce a result that is highly variable. That variability may itself be a learning tool. “‘When a kid produces a messy letter,’ Dr. James said, ‘that might help him learn it’” (Konnikova 2014).
Static, Low-Frequency, and Pulsed Magnetic Fields in Biological Systems
Published in James C. Lin, Electromagnetic Fields in Biological Systems, 2016
It is known that fMRI and MEG are sensitive to the frontal and temporal language functions, respectively. Kamada et al. (2007) established combined use of fMRI and MEG to make reliable identification of global language dominance in pathological brain conditions. The authors investigated 117 patients with brain lesions whose language dominance was successfully confirmed by the Wada test. All patients were asked to generate verbs related to acoustically presented nouns (verb generation) for fMRI and to read three-letter words for fMRI and MEG. The fMRI typically showed prominent activations in the inferior and middle frontal gyri, whereas calculated dipoles on MEG typically clustered in the superior temporal region and the fusiform gyrus of the dominant hemisphere. A total of 87 patients were further analyzed using useful data from both the combined method and the Wada test. The authors observed a 100% match of the combined method results with the results of the Wada test, including two patients who showed expressive and receptive language areas dissociated into bilateral hemispheres. The results demonstrated that this noninvasive and repeatable method is not only highly reliable in determining language dominance, but it can also locate the expressive and receptive language areas separately. The authors suggested that the method is a potent alternative to the invasive procedures of the Wada test and is useful in treating patients with brain lesions.
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Published in Mara Cercignani, Nicholas G. Dowell, Paul S. Tofts, Quantitative MRI of the Brain: Principles of Physical Measurement, 2018
A combined quantitative and functional MRI study in children and adults examined the relationship between WC and function (Gomez et al., 2017). Face memory and place recognition were tested in children and adults while scanning relevant brain regions in the ventral temporal cortex. WC measurement was used to extract MTV (1-WC) for these brain regions. It was shown that in the posterior fusiform gyrus, selective for faces, mean MTV increased by 12.6% from childhood to adulthood. Simulations results indicated that increase in the volume of the myelin sheath is not likely to account for the full extent of this observation.
Computational fluid dynamic simulation of two-fluid non-Newtonian nanohemodynamics through a diseased artery with a stenosis and aneurysm
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Ankita Dubey, B. Vasu, O. Anwar Bég, Rama S. R. Gorla, Ali Kadir
Consider the two-dimensional, laminar, incompressible steady (non-pulsating) hemodynamic flow in an artery with a porous wall. Here the core and peripheral regions are the lumen and porous arterial wall respectively and for convenience the following convention is used throughout the paper - core region (lumen) and a peripheral region (porous arterial wall). Blood is simulated as a non-homogeneous fluid with dispersed uniform nanoparticles. Non-Newtonian characteristics are treated with a dual rheological formulation- namely a Casson fluid model in the core region and a Sisko fluid model in the peripheral region. Thermosolutal flow is considered i.e. both heat and mass (nanoparticle) diffusion are incorporated with associated buoyancy effects. A cylindrical coordinate system is employed, where r is the radial coordinate, z is axial coordinate and φ is azimuthal coordinate. Axisymmetric flow is studied and therefore contribution in the azimuthal (φ) direction is ignored i.e. the flow is only in the radial (r) and axial (z) direction as depicted in Figure 1. A finite length arterial geometry is studied which contains a sinusoidal-shaped stenosis with a fusiform aneurysm. In the arterial segment, the geometry of the outer layer of the mild stenosis and aneurysm is assumed to be described by:
Neurovascular devices for the treatment of intracranial aneurysms: emerging and future technologies
Published in Expert Review of Medical Devices, 2020
In 2018, Arat et al. published a retrospective case series of nine patients treated with two commercially available bioresorbable scaffolds (Absorb or DeSolve scaffolds), four of them for IAs (with scaffold-assisted coiling) and five for atherosclerotic disease [64]. The patients were under a dual antiplatelet regimen. The authors report that the navigation was challenging but feasible in these cases, even though the patient selection included cases with a non-tortuous cerebrovascular anatomy, suitable for navigation by the bulky Bioresorbable Vascular Scaffold (BVS). There was no permanent morbidity or mortality. At a mean follow-up of 22.3 months, one parent artery in the aneurysm group was occluded, and the remaining BVSs showed no significant restenosis. Fusiform luminal enlargement was demonstrated in one aneurysm patient. In two patients treated for stenosis, transient intra-arterial filling defects resembling BVS struts (scaffold silhouette) were demonstrated on early follow-up angiograms. The authors concluded that the BVS should be optimized for cerebral circulation if prospective studies are to be undertaken for cerebrovascular applications, which could be promising.
Effective connectivity inference in the whole-brain network by using rDCM method for investigating the distinction between emotional states in fMRI data
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2023
Naemeh Farahani, Shabnam Ghahari, Emad Fatemizadeh, Ali Motie Nasrabadi
In this study, by considering 44 ROIs, we found other effective connections in addition to the mentioned connections in the previous studies (Fairhall and Ishai 2006; Mazzola et al. 2016; Purves et al. 2017; Seok and Cheong 2019; Farahani et al. 2019). Amongst these connections, there is a connection from the occipital fusiform gyrus to the angular gyrus. The angular gyrus is related to language and recovery of memory. Considering the role of visual regions in these connections, it can be interpreted that during applying emotional audio stimulation, visual and spatial imagination may lead to the appearance of such connectivity in the brain.