Experimental neuropsychological tests of feature ambiguity, attention and structural learning : associations with white matter microstructural integrity in elderly with amnesic and vascular mild cognitive impairment.

Type of content
Theses / Dissertations
Publisher's DOI/URI
Thesis discipline
Psychology
Degree name
Master of Science
Publisher
University of Canterbury. Psychology
Journal Title
Journal ISSN
Volume Title
Language
Date
2014
Authors
Young, Bob Neill
Abstract

Mild cognitive impairment (MCI) is a transition phase between normal aging and Alzheimer’s disease. Individuals with MCI show impairment in cognition as well as corresponding damage to areas of their brain. Performance on tasks such as discriminating objects with ambiguous features has been associated with damage to the perirhinal cortex, while scenes with structural (spatial) elements have been associated with damage to the hippocampus. In addition, attention is regarded as one of the first non-memory domains to decline in MCI. A relatively new MRI technique called diffusion tensor imaging (DTI) is sensitive to white matter microstructural integrity and has been associated with changes due to cognitive decline. 18 MCI (14 amnesic, 4 vascular) and 12 healthy matched controls were assessed in feature ambiguity, attention and structural learning to assess associated deficits in MCI. Associations with white matter microstructural integrity were then investigated. The MCI groups were discovered to perform worse than controls on the test of structural learning. In addition, altered attention networks were found in MCI and were associated with white matter microstructural integrity. No significant differences were found for feature ambiguity. These findings suggest there may be specific damage to the hippocampus while the perirhinal cortex may be preserved in MCI. Furthermore, dysfunction in attention was found to be associated with white matter microstructural integrity. These experimental tests may be useful in assessing dysfunction in MCI and identifying degeneration in white matter microstructural integrity. Further studies with larger sample sizes are needed to validate these findings.

Description
Citation
Keywords
mild cognitive impairment, MCI, diffusion tensor imaging, DTI, neuropsychological testing, tract-based spatial statistics, TBSS, Alzheimer's Disease, MRI, Feature Ambiguity, Attention, Structural Learning
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Rights
Copyright Bob Neill Young