The Rey–Osterrieth Complex Figure as a measure of executive function in childhood

Abstract

In adults, the Rey–Osterrieth Complex Figure (ROCF) can be used for the assessment of not only visuoconstructional ability and visual memory, but also executive function in adults. We studied whether ROCF scores also correlated with executive function in childhood. The subjects consisted of 56 patients with various neurological diseases (5 years 7 months–14 years 11 months; mean: 8 years 8 months; M 42, F 14) whose full-scale IQs were 70 or higher (mean: 93.3). All subjects underwent the Wechsler Intelligence Scale for children third edition (WISC-III) and various psychological tests focusing on executive function. We evaluated the ROCF with the Boston Qualitative Scoring System (BQSS). We calculated the partial correlation coefficients between the BQSS Summary Scores and representative scores of other executive function tests, using age as the control variable. Among the scores of the various examinations, the Perseverative Errors of Nelson of the Wisconsin Card Sorting Test, the raw scores of the Mazes (WISC-III), the Digit Span (WISC-III), and the Block Design (WISC-III) were correlated significantly with two to four BQSS Summary Scores (P<0.05 or P<0.01). In contrast, the scores of the Trail Making Test, the Stroop Test, and the Commission Error of Continuous Performance Test-II did not show a significant correlation with any of the BQSS Summary Scores. The ROCF evaluated with the BQSS reflects not only visuoperceptual ability and visuoconstructional ability, but also executive function, especially planning and organization. However, a new BQSS Summary Score should be devised since no existing BQSS index specifically reflects executive functions with an outstandingly strong correlation.

Introduction

Executive function is a relatively new concept that reflects ‘highly advanced’ mechanisms comprising many components of cognitive processes [1]. Executive dysfunction can cause impairments in planning, cognitive fluency, and judgment without lowering intelligence [2]. Lately, executive dysfunction is attracting attention as a basic mechanism of pervasive developmental disorders and attention deficit/hyperactivity disorders [3], [4].

To assess executive function, there are various procedures such as the Wisconsin Card Sorting Test, the Trail Making Test, the Stroop Test, the Verbal or Design Fluency Test, the Continuous Performance Test and the Gambling Task Test [5].

In 1941, Andre Rey devised a complex geometric figure to assess visuoconstructional ability and visual memory performance in brain-injured patients. Three years later, Paul Osterrieth invented a scoring system to standardize Rey's original procedure and presented normative data for the test [6]. Thereafter, this procedure has been called the Rey–Osterrieth Complex Figure (ROCF) and has been used for the assessment of visuoconstructional ability and visual memory. Thanks to the complexity of the figure, the ROCF also reflects cognitive processes regarding strategies and organizational approach at the time of drawing the figure. Consequently, the ROCF has the potential to be a useful method for the assessment of executive function [7].

Among various ROCF administration procedures, the most commonly used scoring method is Taylor's method [8]. Since this 36-point scoring system is based on the presence and accuracy of the 18 units of the ROCF, it cannot evaluate qualitative features such as drawing steps.

The Boston Qualitative Scoring System (BQSS) for the ROCF was published in 1999 [9]. The BQSS was introduced predominantly for adults. It provides, first, a comprehensive set of qualitative ratings based on the presence and accuracy of elements, and the process of drawing, and, second, a quantitative Summary Score [10]. A study on adult subjects showed a significant correlation between some of the BQSS scores and scores of several executive function tests [10]. Although a standardization of the BQSS was performed with 433 adults ranging in age from 18 to 94, there are no normative data for those less than 17 years of age. Furthermore, the psychometric properties of the BQSS in childhood have not been fully clarified [11], [12]. Therefore, we studied the correlation between BQSS Summary Scores and various kinds of psychological test scores focusing mainly on executive function in children. From the statistical point of view, if subjects are homogeneous, variances of variables become small. As a result, the correlation that exists innately might become obscure. Therefore, we chose patients having various kinds and degrees of brain dysfunctions without mental retardation as the subjects of our study.

The goals of this study were as follows: (1) to elucidate whether executive function contributes significantly to ROCF scores in childhood, and (2) to determine which BQSS Summary Score best reflects executive function, if a significant correlation indeed exists.