The computerized object and abstract designs test (COAD): A pilot study of a new test of visual working memory

Abstract

To investigate the clinical and theoretical validity of a new computerized test of visual working memory; the computerized object and abstract designs (COAD) test. The COAD test was designed to be consistent with Baddeley's inclusion of the 'episodic buffer' in the 'multicomponent model' of working memory. A cross-sectional design was used with two brain lesion groups (left N=9 and right hemisphere N=12) and a control group N=18. The participants had to complete the new test, along with standardized tests of visual working memory in current clinical use (visual patterns test and spatial span test). Differences between groups, as well as between tests were investigated. Correlations were performed across tests. Regression models were used to further evaluate the COAD clinical sensitivity in comparison with the other tests of visual working memory. Significant differences were observed, as predicted, between groups and between design types. The COAD test was significantly correlated with both the visual patterns Test and the spatial span test. The COAD test also proved to be more sensitive in detecting brain injury resulting in visual working memory deficits, than the standardized tests. The results are discussed in relation to the COAD test's potential utility in the early detection of specific degenerative neurological disorders as well as the potential to be used in identifying deficits in visual working memory and in neurorehabilitation. It is concluded that the COAD test is a clinically valid psychometric test and is a more sensitive instrument than current standardized tests of visual working memory in clinical use.