scholarly journals Accurate 3D Left-Right Brain Hemisphere Segmentation in MR Images Based on Shape Bottlenecks and Partial Volume Estimation

Author(s):  
Lu Zhao ◽  
Jussi Tohka ◽  
Ulla Ruotsalainen
2014 ◽  
Vol 33 (2) ◽  
pp. 462-480 ◽  
Author(s):  
Frank Heckel ◽  
Hans Meine ◽  
Jan H. Moltz ◽  
Jan-Martin Kuhnigk ◽  
Johannes T. Heverhagen ◽  
...  

2002 ◽  
Vol 205 (12) ◽  
pp. 1795-1805 ◽  
Author(s):  
Helmut Prior ◽  
Frank Lingenauber ◽  
Jörg Nitschke ◽  
Onur Güntürkün

SUMMARY The pigeon's use of different visuo-spatial cues was studied under controlled laboratory conditions that simulated analogous aspects of a homing situation. The birds first learned the route to a goal that was not visible from the starting location, but became visible as it was approached. Birds could orientate within a mainly geometric global reference frame, using prominent landmarks within their range, or by `piloting' along local cues. After learning the route, the birds were tested from familiar and unfamiliar release points, and several aspects of the available cues were varied systematically. The study explored the contribution of the left and right brain hemispheres by performing tests with the right or left eye occluded. The results show that pigeons can establish accurate bearings towards a non-visible goal by using a global reference frame only. Furthermore, there was a peak of searching activity at the location predicted by the global reference frame. Search at this location and directedness of the bearings were equally high with both right and left eye, suggesting that both brain hemispheres have the same competence level for these components of the task. A lateralization effect occurred when prominent landmarks were removed or translated. While the right brain hemisphere completely ignored such changes,the left brain hemisphere was distracted by removal of landmarks. After translation of landmarks, the left but not the right brain hemisphere allocated part of the searching activity to the site predicted by the new landmark position. The results show that a mainly geometric global visual reference frame is sufficient to determine exact bearings from familiar and unfamiliar release points. Overall, the results suggest a model of brain lateralization with a well-developed global spatial reference system in either hemisphere and an extra capacity for the processing of object features in the left brain.


2008 ◽  
Vol 41 (2) ◽  
pp. 9619-9624
Author(s):  
László Szilágyi ◽  
Sándor M. Szilágyi ◽  
Balázs Benyó ◽  
Zoltán Benyó

Radiology ◽  
2008 ◽  
Vol 246 (2) ◽  
pp. 581-588 ◽  
Author(s):  
Einar Heiberg ◽  
Martin Ugander ◽  
Henrik Engblom ◽  
Matthias Götberg ◽  
Göran K. Olivecrona ◽  
...  

2015 ◽  
Vol 2 ◽  
pp. 111-119 ◽  
Author(s):  
Belinda M. Go ◽  
Doly Joy C. Celindro

This is the last phase of a four-year study which aimed to determine the significance of the difference in the mathematics (math) performance of the participants when grouped according to their hemispheric dominance (HD). The study was anchored in the Split-Brain or Lateralization Theory of Roger Wolcott Sperry which states that the brain is divided into two hemispheres, the left, and the right hemisphere. The participants were eighty-eight (88) fourth-year college students from the courses of Bachelor of Science in Mathematics (BSM), Bachelor of Science in Education major in Mathematics (BSEd), Bachelor of Science in Electrical Engineering (BSEE), Bachelor of Science in Electronics and Communication Engineering (BSECE), and Bachelor of Science in Mechanical Engineering major in Automotive Engineering (BSMEAE) at Western Visayas College of Science and Technology SY 2014-2015. The participants’ HD was determined by the use of a researcher-made 46-item Hemispheric Brain Dominance Test while their mathematics performance was based on their Math classes average final grades. The statistical tools used were the mean, standard deviation, Mann-Whitney, Kruskal-Wallis, and Post hoc tests. The hypothesis was set at the 0.05 alpha level. As an entire group, the left brain was the dominant brain hemisphere among the participants from phase I to phase IV. When the participants were grouped according to program in phase I, the BSM, BSEd, and BSMEAE was left-brain dominant while the BSEE participants were right-brain dominant. The BSECE had an equal number of left-brained and right-brained participants. In phase II, the dominant brain hemisphere was the left brain. Only the BSEE participants were right-brain dominant. In phase III, the dominant brain hemisphere was the left brain, except for the BSMEAE where there was an equal number of left-brained and right-brained participants. In phase IV, all participants from the different programs were left-brained. Only the BSEE participants were right-brain dominant. As an entire group, phase I and II participants had “fair” mathematics performance; phase III had “good” mathematics performance, and phase IV had “very good” mathematics performance. When the participants who were right-brained were grouped according to mathematics performance, phase I had “conditional” mathematics performance; phase II and III had “fair” mathematics performance; and phase IV had “good” mathematics performance. Those who were left-brain dominant had “fair” mathematics performance in phase I, “good” mathematics performance in phase II and III, and “very good” mathematics performance in phase IV. In all phases of the study, significant differences existed in the level of mathematics performance when the participants were grouped according to their hemispheric brain dominance. The “left-brained” performed better in mathematics than the “right-brained”. There was a significant decrease in the enrolment of participants who were right-brain dominant because they shifted to other courses or they transferred to other schools. In phases, I, II and III, significant differences existed in the level of mathematics performance when the participants were grouped according to their program. There is no significant difference in the hemispheric brain dominance of the participants when grouped according to the phase of the study. This implies that the slight changes in the hemispheric brain dominance of the participants were not significant in the last four years.


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