Dikkat Ağları Modelinin Rekabet Kuramı, Temsil Düzeyi ve Yaş Değişkenleri Açısından İncelenmesi: Fmrı Destekli Bir Çalışma

Abstract

The purpose of this thesis is to examine the functioning and neural basis of the hierarchical alerting, orientating, executive attention network components of the Attentional Networks Model (ANM), and mental number representations in the context of attention. Three different experiments were designed to test the hypotheses formed within the framework of Competition Theory. In Experiment 1, the alerting, orientating, and executive attention network tasks created by combining the Nonorthogonal-Attentional Networks Test (Nonorthogonal-ANT) tasks and the Attentional Dwell Time (AD) paradigm (N = 45); in Experiment 2, the task designed by integrating analogical and Arabic number representations to the AD paradigm (N = 15); in the first stage of Experiment 3, 3 tasks (N = 20) designed by integrating analogical, Arabic number and verbal representations to the Nonorthogonal-ANT were applied to healthy adults. In the second stage, fMRI records were obtained while the simplified executive attention task was applied to 10 healthy children and 10 healthy adults. As a result, it was observed that parallel information processing mechanism is valid for all ANM components in line with Competition Theory (Experiment 1), and that there was no top-down selection bias on the second representation/target due to simultaneous and parallel activation of the representations, under the same numerical value condition (Experiment 2). In Experiment 3, the SNARC effect, which represents the access to magnitude information, was observed only in Arabic number representation, and in children at all representation levels in distractor absent condition. In the analogical representation, left and right inferior parietal lobe, right inferior frontal gyrus (Perisylvian areas) (Broca area), left and right precuneus areas were found active while the right inferior frontal gyrus was active during analogical representation in the adults. Activations were found in the left parahippocampal gyrus in Arabic number representation, and in children in the left superior temporal gyrus region. In conclusion, it was observed that parallel information processing is valid in mental number processing, and that activations in the right medial frontal gyrus, left anterior cingulate, left precuneus, left putamen (basal ganglia) regions in executive attention are consistent with the literature. In addition, the development of the executive attention network component continues in children with the age between 10-12 years old.