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Review of the Human Brain and EEG Signals
Published in Teodiano Freire Bastos-Filho, Introduction to Non-Invasive EEG-Based Brain–Computer Interfaces for Assistive Technologies, 2020
Alessandro Botti Benevides, Alan Silva da Paz Floriano, Mario Sarcinelli-Filho, Teodiano Freire Bastos-Filho
This section analyzes the circuits that are involved in motor activity, linking different areas of the motor cortex. Actually, the initiation of voluntary movements engages areas in frontal, prefrontal, and parietal cortices, which are connected to the basal nuclei,20 deep in the brain. The basal nuclei receive most of its input signals from the cerebral cortex and return almost all of their output signals to the cerebral cortex. In each hemisphere, the basal nuclei are formed by the caudate nucleus, putamen,21 globus pallidus,22 subthalamic nucleus, and substantia nigra,23 which are located around the thalamus, occupying a large portion of the internal regions of both brain hemispheres (Figure 1.12a). The caudate and putamen together are called the striatum, which is the target from the cortical afference to the basal nuclei [2].
The Deep Brain Connectome
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
Ifije E. Ohiorhenuan, Vance L. Fredrickson, Mark A. Liker
The basal ganglia consist of the caudate nucleus, the putamen, the globus pallidus, and the nucleus accumbens. The caudate and putamen, which together comprise the striatum, receive the majority of afferent input to the basal ganglia, including projections from the cortex, the substantia nigra, and the amygdala. The basal ganglia circuitry is notable for consisting of multiple parallel loops involving connections between cortical association areas, through the basal ganglia to the thalamus and back to the cortex. Initially, five parallel circuits were defined: the “motor circuit,” the “oculomotor circuit,” the “dorsolateral prefrontal circuit,” the “lateral orbitofrontal circuit,” and the “anterior cingulate circuit” (Alexander et al. 1986). Since then additional basal ganglia–thalamocortical circuits have been identified. These circuits are integral to motor learning, sequencing of movements, attention, working memory, and learning. Our understanding of the basal ganglia has relied on not only animal models and imaging methods but also, importantly, clinical studies of patient undergoing surgical procedures, which have, sometimes serendipitously, uncovered critical roles for the basal ganglia in modulating human disease.
Neuroimaging
Published in Sarah McWilliams, Practical Radiological Anatomy, 2011
o The basal ganglia consist of the caudate nucleus which abuts the internal capsule medially and the lentiform nucleus which is lateral to the genu of the internal cap-sule. These are supplied by the lenticulostriate vessels, which are small end-arteries coming off the middle cer-ebral artery. Small-vessel ischaemia affects these and leads to small lacunar infarcts within the basal ganglia.
Effects of Temporal Light Modulation on Cognitive Performance,Eye Movements, and Brain Function
Published in LEUKOS, 2023
Jennifer A. Veitch, Patricia Van Roon, Amedeo D’Angiulli, Arnold Wilkins, Brad Lehman, Greg J. Burns, E. Erhan Dikel
The dipole analysis showed two consistent patterns of results. First, the analysis showed the upper portion of the cerebellum (culmen and tuber of vermis) as the main source of activity for the entire ERP epoch, indicating cross-hemisphere communication. Concurrently, the analysis identified less intense but clear sources in the left hemisphere, notably, the pulvinar for congruent trials, and the caudate nucleus in the basal ganglia and the lateral dorsal nucleus of the thalamus for incongruent trials. Further analyses showed a consistent pattern of sources during the time intervals of early activation (between 60 and 340 ms after stimulus presentation) parallel to the generators for the overall epoch. For both congruent and incongruent trials, dipole activations were localized to the striate and extrastriate occipital and inferotemporal areas in the left and right hemisphere. (See Appendix D for the full results, including the tests that were not statistically significant, in Tables D18 to D21.)
Gradient boosted trees for spatial data and its application to medical imaging data
Published in IISE Transactions on Healthcare Systems Engineering, 2022
Reza Iranzad, Xiao Liu, W. Art Chaovalitwongse, Daniel Hippe, Shouyi Wang, Jie Han, Phawis Thammasorn, Chunyan Duan, Jing Zeng, Stephen Bowen
In fact, gradient boosted trees have been used for medical applications. Leveraging an open-source implementation, Oguz et al. (2017) illustrated the gradient boosted trees in a corrective learning for the segmentation of the caudate nucleus, putamen and hippocampus. de Melo et al. (2018) applied Light Gradient Boosting Machine to detect the posterior wall of the left ventricle from echocardiogram images. Fu et al. (2020) developed gradient boosted trees classifier to diagnose the lesion as malignant or benign for Breast Cancer Diagnosis. Nishio et al. (2018) performed the comparison between support vector machine and XGBoost for computer-aided diagnosis of lung nodule. Xie et al. (2019) applied extreme gradient boosting and gradient boosting machine to predict modified Rankin scale scores using biomarkers for 512 patients enrolled in a retrospective study.
Noninvasive vagus nerve stimulation in Parkinson’s disease: current status and future prospects
Published in Expert Review of Medical Devices, 2021
Hilmar P. Sigurdsson, Rachael Raw, Heather Hunter, Mark R. Baker, John-Paul Taylor, Lynn Rochester, Alison J. Yarnall
The neural correlates of VNS remain enigmatic, and imaging studies have produced somewhat inconsistent results. The low temporal and spatial resolutions of the imaging modalities used, varying stimulation parameters, limited sample sizes, and the clinical populations assessed are all potentially confounding factors. In healthy volunteers undergoing nVNS, the aim is to measure changes in the blood oxygenation level dependent (BOLD) response in vagal afferent pathway target regions. To date, at least eight studies using whole-brain exploratory analysis have been reported [58–65]. Using taVNS, some [59–62] but not others [58,63] showed increased BOLD response in the nucleus tractus solitarius (NTS) and LC. Conversely, Kraus and colleagues [59] reported decreased BOLD response in both regions during taVNS. Across these studies, increased activity (during taVNS relative to rest or sham stimulation) has been found in regions encompassing salience (insula, anterior cingulate), basal ganglia (caudate nucleus, putamen), thalamic, and cerebellar brain networks. By contrast, deactivation was observed in the limbic system and temporal lobe when sham stimulation has been compared to active stimulation. It is noteworthy that the exact neural connections of the ABVN are not known. The tragus is innervated, for example, only by the great auricular nerve and the auriculotemporal nerve, not the vagus nerve [66].