Title

The Groton Maze Learning Test: Construct validity, factor structure, and application to normal aging, pathological gambling, and attention deficit hyperactivity disorder

Date of Completion

January 2007

Abstract

Spatial working memory is a useful construct upon which to base translational models of novel pharmacotherapies. To date, however, a reliable, valid cognitive instrument for use in translational neuropsychological research is not available. Moreover, many of the spatial working memory tasks developed for use in humans have psychometric limitations, are not suitable for repeated use, and do not assess the full range of cognitive operations that underlie spatial working memory (e.g., processing speed, response inhibition, planning, and procedural learning). Disentangling these dimensions in a single neuropsychological instrument may provide useful information regarding domains of cognition that underlie spatial working memory and learning. Assessment of these cognitive domains, which may be differentially sensitive to early neurodegenerative changes and pharmacologic interventions, may be useful in assessing early cognitive decline and treatment response.^ This dissertation evaluated the construct validity, factor structure, and clinical utility of the Groton Maze Learning Test (GMLT), a novel computerized neuropsychological test of spatial working memory and error monitoring. Specifically, it (1) examined the construct validity of the GMLT using well-known neuropsychological measures of executive function; (2) analyzed the factor structure of GMLT outcome measures and the stability of this factor structure after repeated assessment; (3) evaluated the utility of the GMLT in assessing normal aging related cognitive change; and (4) examined the clinical utility of the GMLT in detecting cognitive impairment in two populations with known deficits in executive function—pathological gamblers and children with attention-deficit/hyperactivity disorder (ADHD).^ Results of this dissertation demonstrated that GMLT measures correlated with a wide array of neuropsychological tests of including information-processing speed, attention, working memory, learning, planning, and route selection. Learning efficiency on the GMLT also correlated with sociotropy, a personality construct characterized by dependency on others and concern about disapproval. Exploratory factor analyses of GMLT measures consistently yielded a two-factor solution of "Error Monitoring" and "Learning Efficiency," which was stable over repeated assessments. The GMLT was sensitive in detecting normal aging-related cognitive decline, neuropsychological correlates of pathological gambling, and in assessing cognitive effects of stimulant treatment in children with ADHD. ^