Development and validation of a spatial parallel of the California Verbal Learning Test using detoxified long-term alcoholics
The purpose of this study was to develop a clinical test of spatial memory that models the list-learning paradigm of the California Verbal Learning Test (CVLT). The CVLT is a test of recall for serially presented words across multiple acquisition trials, and delayed recall and recognition. Despite its popularity, few tests of non-verbal memory have been developed that model this paradigm. Drawing on the approaches of previous spatial memory tests such as the 7/24 Spatial Recall Test and the Visual Spatial Learning Test, a new test of spatial memory was developed to parallel the format of the CVLT and generate analogous dependent variables. This new spatial learning test (SLT) assesses recall for the location of serially presented stimuli in a fixed array of randomly placed targets. In a pilot phase, three prototypes of the SLT (8-item, 12-item, and 16-item) were administered to six student volunteers each, along with the CVLT. The 12-item SLT most closely approximated the difficulty of the CVLT, and was administered to an additional 20 student volunteers to assess potential floor and ceiling effects. No such effects were noted, and the SLT generated score distributions similar to those of the CVLT. Formal validation of the SLT was sought by administering it, along with a brief battery of other tests, to 25 detoxified long-term alcoholics (a population associated with mild memory impairment) and 25 non-alcoholic community volunteers matched for age, education, and socioeconomic status. Clinical participants were recruited from a residential substance abuse facility ( n = 16), and an inpatient substance abuse unit at a state hospital (n = 9). Participants were administered the SLT, CVLT, Rey-Osterrieth Complex Figure Test (a test of figural memory), along with verbal and spatial attention tests. Clinical participants scored significantly lower on the SLT and CVLT than controls, with no significant differences between the tests, on four primary indices of acquisition, delayed recall, and delayed recognition. The results that the SLT is a valid test of memory. Correlations among the SLT, CVLT, and other measures provided equivocal evidence that the SLT is a modality-specific test of spatial memory.