An examination of the construct validity and factor structure of the Groton Maze Learning Test, a new measure of spatial working memory, learning efficiency, and error monitoring

This study examined the construct validity of the Groton Maze Learning Test (GMLT) in assessing processing speed, working memory, and aspects of executive function in healthy adults. Performance on GMLT outcome measures was compared to performance on tests of psychomotor speed, working memory, and learning from the CogState computerized cognitive test battery (CGS; http://www.cogstate.com/). The factor structure of the GMLT was evaluated using exploratory factor analysis. The stability of this factor structure was examined in a large sample of patients undergoing parathyroidectomy or thyroidectomy. Results of this study suggest that the GMLT measures of spatial learning efficiency and error monitoring correlate with CogState measures of attention, working memory, and learning. Exploratory factor analysis yielded a two-factor solution of error monitoring and learning efficiency, which was stable across repeated assessments. (C) 2008 National Academy of Neuropsychology. Published by Elsevier Ltd. All rights reserved.