Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Acıbadem Mehmet Ali Aydınlar Üniversitesi, Mühendislik ve Doğa Bilimleri Fakültesi, Biyomedikal Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2020
Tezin Dili: İngilizce
Öğrenci: Burçin Tatlıeşme
Danışman: Sinem Burcu Erdoğan, Ata Akın
Özet:
The prefrontal cortex (PFC) is a brain region that plays a central and executive role in attention, cognitive processing and working memory. Therefore, examination of PFC with non-invasive functional imaging methods is crucial in understanding the dynamics of cognitive functions, also for early detection of disease-related alterations. In this study, a new technique is proposed that can be used to diagnose disorders such as hyperactivity, and attention deficiency, where PFC networks are highly involved. This method is based on recording brain hemodynamics with an fNIRS device during a Stroop task. In this study, 29 adult subjects (23,2 ± 4,5 years, 11 females) without any neuropsychiatric diseases performed a Stroop task. Attention, response control and working memory were evaluated with a 16-channel fNIRS system. For each subject, the global efficiency (GE) scores were computed for rest1, test and rest2 times. The ratio of test GE to rest GE scores were used to classify the subjects into two groups (Low Ratio, LR and High Ratio, HR). The HR and LR groups were found to be statistically significantly different. It was remarkable that the HR group used less time compared to LR’s response time. When GE connectivity maps are analyzed, it was noticed that HRs established better direct connections during the test compared to the rest moment and showed a better focus. However, maps of the LR group, a similar focus was not observed during the test. In addition, Neural Efficiency of each participant, increased linearly with GE scores. Based on these results, it is proposed that subjects with higher GE ratios during Stroop test have “higher focus and inhibition ability” when compared to subjects with lower GE ratios. The functional connectivity seems to be more efficient in the task focused brain as higher connectivity scores are associated with higher Neural Efficiency and lower response durations. These results support the suitability of brain connectivity measures obtained from fNIRS as potential diagnostic biomarkers for differentiating and diagnosing cognitive disorders related to attention deficiency and impulsivity.
Keywords: Stroop, Function Near Infrared Spectroscopy (fNIRS), Global Efficiency, Attention, Focus