eva‎luating the effects of people's age on the brain effective connectivity features using fMRI data

9/16/2024 12:00:00 AM

With increasing age, changes occur in the brain. Aging generally disrupts various brain functions such as motor skills, cognitive abilities, processing speed, and memory. Given the increasing number of elderly individuals in societies, there is a strong need for studies on age-related brain changes. In response to this demand, this research focuses on examining the effective connectivity in different age groups using resting-state functional magnetic resonance imaging (rs-fMRI). The aim is to gain a better understanding of age-related changes in the brain. In this study, we utilize the lifespan data of the Human Connectome Project (HCP) in three age groups and examine effective connectivity in different age ranges using graph theory. The Granger causality method with sliding window was employed to calculate dynamic effective connectivity (dEC). After extracting graph features, statistical analyses were performed to compare the age groups. Subsequently, conclusions are drawn on whether significant differences exist between the groups. Discriminative features were selected using the Kruskal-Wallis test and Fisher score. Support vector machine and decision tree classifiers were used to classify the different age groups based on the extracted graph features. Based on the obtained results, it can be concluded that there are significant differences in the effective connectivity among the three age groups. In the connectivity networks of different age groups, a negative assortativity coefficient (disassortativity) was observed. The global efficiency exhibited a decreasing trend and the transitivity feature showed an increasing trend with the advancing age. The decision tree classifier showed an accuracy of 86.6% with Kruskal-Wallis selected features. In-degree, betweenness centrality, flow coefficient, and clustering coefficient were the most discriminative graph measures in the feature selection process, capable of distinguishing different age groups. Regions of the left superior frontal gyrus, left and right putamen, vermis 4-5 and 3, right calcarine sulcus, and right medial orbitofrontal cortex in the AAL atlas were influential in classifying age groups. This study demonstrates that changes in effective connectivity in different age groups can serve as a tool for better understanding brain function.

تصويربرداري تشديد مغناطيسي عملكردي , پروژه كانكتوم انسان , ارتباطات موثر مغزي , افزايش سن

Functional magnetic resonance imaging؛ , human connectome project , effective connectivity , ageing

Nakisa Nourzadegan

Dr. Mohammad Reza Daliri , Dr. S.H Sabzpoushan