Title

A multi-component model of attention deficits: Dysfunction of attention-working memory-executive functions as assessed by the CVLT-C

Date of Completion

January 1998

Keywords

Education, Tests and Measurements|Education, Educational Psychology|Education, Special|Psychology, Cognitive

Degree

Ph.D.

Abstract

This study considers Attention Deficit Hyperactivity Disorder (AD/HD) from a cognitive processing perspective utilizing current concepts of brain structure and function. Theorists hold that attention, working memory (WM) and executive functions (EF) are interrelated and interdependent systems. AD/HDs are a heterogeneous group with idiosyncratic strengths and weaknesses, many of whom experience academic difficulties. There is no consensus what patterns of weaknesses contribute to academic failure.^ The California Verbal Learning Test, Children's Ed. (CVLT-C) is used to operationally define four components of attention--WM-EF: IN (Initiate), SU (Sustain), IB (Inhibit), and SH (Shift). Performance data of 17 AD/HDs (mean 16.9 years) with and without stimulant medication, and 16 Comparisons (mean 16.2 years) test four questions: Will IN, SU, IB, and SH discriminate between AD/HD and Comparisons? Do AD/HDs cluster by performance patterns? Are the measures sensitive to performance changes reactive to the use of stimulant medication? Do IN, SU, IB, and SH correlate to academic performance?^ There are four principal findings. (1) No Meds, Meds, and Comparisons differ on IB ($x\sp{2} =$ 11.43, p $<$.003). In separate goodness of fit analyses, there are significant differences for SU, IB, and SH. (2) No Meds, Meds, and Comparisons subgroup by their performance on IN, SU, IB, and SH. Iterative Cluster Analysis yields a five-group solution (IN F $\rm = 37.35,\ p<.0001;\ SU\ F = 8.58,\ p<.0001;\ IB\ F = 21.07,\ p<.0001;\ SH\ F = 7.53,\ p<.0001$). Taken together these findings suggest that this method is a valuable assessment tool to discriminate between groups and to formulate performance based subgroups. (3) With the introduction of stimulant medications, AD/HDs performance improves on IN (Z $\rm = -3.06,\ p<.002$) and declines on SH (Z $\rm = -2.94,\ p<.003$). Further, two important trends emerge: 52.9% of the sample improve on IB and 52.9% decline on SU. These findings are explored relative to two controversies in the literature: high vs. low dose and over restriction of focus. (4) There is a correlation between SH and the Interdisciplinary Writing Sample, Connecticut Academic Performance Test ($r =$.57, p $<$.02). Thus students with impaired SH do poorly on a measure of academic performance. ^