Investigation of line bisection activity in the brain by a sensory-motor task : an fMRI study

Gümüş, Burçin
Strongly right handed healthy people bias the selection of the midpoint leftward by neglecting right side of a line in line bisection task which is used for clinical assessment of neglect syndrome. The line bisection task relies mostly on visual judgements; involving a fronto-parietal visual loop. How does line bisection manifest itself in the realm of other senses is less addressed. In this study, we developed a tactile line bisection task compatible with MR device and implemented line bisection under both tactile and visual conditions in order not only to reveal neural substrates of line bisection when somatosensory cortex is recruited, but also to investigate whether there are different attentional mechanisms underlying line bisection in different sensory modalities. After administering tactile and visual line bisection task through fMRI experiments to a group of strongly right handed people, we observed additional brain activity in contralateral medial frontal gyrus and contralateral inferior parietal lobule when the task is performed with right hand in tactile sense instead of visual sense. Furthermore, the activity maps changed drastically when left hand is used instead of right hand, causing recruitment of large areas in ipsilateral temporal cortex probably due to dominating proprioceptive processes. The results provide a contribution to the idea that there are different cognitive processes underlying line bisection under tactile and visual senses.


Improving the sub-cortical gm segmentation using evolutionary hierarchical region merging
Çiftçioğlu, Mustafa Ulaş; Gökçay, Didem; Department of Medical Informatics (2011)
Segmentation of sub-cortical Gray Matter (GM) structures in magnetic resonance brain images is crucial in clinic and research for many purposes such as early diagnosis of neurological diseases, guidance of surgical operations and longitudinal volumetric studies. Unfortunately, the algorithms that segment the brain into 3 tissues usually suffer from poor performance in the sub-cortical region. In order to increase the detection of sub-cortical GM structures, an evolutionary hierarchical region merging approa...
Predicting bone remodeling around tissue- and bone-level dental implants used in reduced bone width
Eser, Atilim; Tönük, Ergin; Akça, Kıvanç; Dard, Michel M.; Cehreli, Murat Cavit (Elsevier BV, 2013-09-03)
The objective of this study was to predict time-dependent bone remodeling around tissue- and bone-level dental implants used in patients with reduced bone width. The remodeling of bone around titanium tissue-level, and titanium and titanium-zirconium alloy bone-level implants was studied under 100 N oblique load for one month by implementing the Stanford theory into three-dimensional finite element models. Maximum principal stress, minimum principal stress, and strain energy density in pen-implant bone and ...
Analysis of factors affecting baseline SF-36 Mental Component Summary in Adult Spinal Deformity and its impact on surgical outcomes
Mmopelwa, Tiro; Ayhan, Selim; Yuksel, Selcen; Nabiyev, Vugar; Niyazi, Asli; Pellise, Ferran; Alanay, Ahmet; Sanchez Perez Grueso, Francisco Javier; Kleinstuck, Frank; Obeid, Ibrahim; Acaroglu, Emre (AVES Publishing Co., 2018-5)
Objectives: To identify the factors that affect SF-36 mental component summary (MCS) in patients with adult spinal deformity (ASD) at the time of presentation, and to analyse the effect of SF-36 MCS on clinical outcomes in surgically treated patients. Methods: Prospectively collected data from a multicentric ASD database was analysed for baseline parameters. Then, the same database for surgically treated patients with a minimum of 1-year follow-up was analysed to see the effect of baseline SF-36 MCS on t...
Prevalence of otologic complaints in patients with temporomandibular disorder
Tuz, HH; Onder, EM; Kisnisci, RS (Elsevier BV, 2003-06-01)
The prevalence and rank of order of 4 otologic complaints in 200 temporomandibular disorder (TMD) patients, as well as the relationship between the complaints and TMD subgroups, were investigated and compared with an asymptomatic control group. No subjective otologic complaints were reported by 45 (22.5%) TMD patients; the remaining 155 (77.5%) patients had at least 1 otologic complaint. Otalgia, tinnitus, vertigo, and hearing loss were reported by 63.6%, 59.1%, 50%, and 36.4%, respectively, of the subjects...
Computerized hybrid decision-making system for hormone replacement therapy in menopausal women
Bacak, Hikmet Özge; Leblebicioğlu, Mehmet Kemal; TANAÇAN, ATAKAN; BEKSAÇ, MEHMET SİNAN (IOS Press, 2019-01-01)
BACKGROUND: The diversity of the results of different hormone replacement therapy (HRT) protocols and the fuzziness of the conclusions have caused problems in routine clinical practice.
Citation Formats
B. Gümüş, “Investigation of line bisection activity in the brain by a sensory-motor task : an fMRI study ,” M.S. - Master of Science, Middle East Technical University, 2013.