The Reference Ability Neural Network Study: Motivation, design, and initial feasibility analyses

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2014-12, Vol.103, p.139-151
• Main Authors: Stern, Yaakov, Habeck, Christian, Steffener, Jason, Barulli, Daniel, Gazes, Yunglin, Razlighi, Qolamreza, Shaked, Danielle, Salthouse, Timothy
• Format: Article
• Language: English
• Subjects: Adult; Adults; Age; Age differences; Aged; Aged, 80 and over; Aging; Aging - physiology; Biological and medical sciences; Brain - physiology; Brain mapping; Brain Mapping - methods; Brain research; Cognition & reasoning; Cognition - physiology; Cognitive ability; Cognitive aging; Convergent/discriminant validity; Data processing; Feasibility Studies; Female; fMRI; Functional magnetic resonance imaging; Fundamental and applied biological sciences. Psychology; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging - methods; Male; Medical imaging; Memory; Middle Aged; Nerve Net - physiology; Neural networks; Neuroimaging; Psychologists; Quantitative psychology; Research Design; Researchers; Studies; Validity; Vertebrates: nervous system and sense organs; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2014.09.029

We introduce and describe the Reference Ability Neural Network Study and provide initial feasibility data. Based on analyses of large test batteries administered to individuals ranging from young to old, four latent variables, or reference abilities (RAs) that capture the majority of the variance in age-related cognitive change have been identified: episodic memory, fluid reasoning, perceptual speed, and vocabulary. We aim to determine whether spatial fMRI networks can be derived that are uniquely associated with the performance of each reference ability. We plan to image 375 healthy adults (50 per decade from age 20 to 50; 75 per decade from age 50 to 80) while performing a set of 12 cognitive tasks. Data on 174 participants are reported here. Three tasks were grouped a priori into each of the four reference ability domains. We first assessed to what extent both cognitive task scores and activation patterns readily show convergent and discriminant validity, i.e. increased similarity between tasks within the same domain and decreased similarity between tasks between domains, respectively. Block-based time-series analysis of each individual task was conducted for each participant via general linear modeling. We partialled activation common to all tasks out of the imaging data. For both test scores and activation topographies, we then calculated correlations for each of 66 possible pairings of tasks, and compared the magnitude of correlation of tasks within reference ability domains to that of tasks between domains. For the behavioral data, globally there were significantly stronger inter-task correlations within than between domains. When examining individual abilities, 3 of the domains also met these criteria but memory reached only borderline significance. Overall there was greater topographic similarity within reference abilities than between them (p