The Effect of Culture on Two Information-Processing Speed Tests

The Symbol Digit Modalities Test (SDMT) has been proposed to replace the Paced Auditory Serial Addition Test-3 (PASAT-3) in the Multiple Sclerosis Functional Composite because it has the same validity but easy and shorter administration. However, among the two tests, the one that is most affected by culture is still unknown. The purpose of this study was to compare the performance of Argentinian and North American populations on the SDMT and PASAT-3. The SDMT and PASAT-3 were administered to 137 healthy volunteers from Buffalo, NY, and 137 healthy participants from Buenos Aires, Argentina. Participants were matched by gender, age (±2), and education (±1). Significant differences were found on the SDMT but not on the PASAT-3. Significant and low correlations were found between the tests and years of education. The SDMT is more affected by culture than is the PASAT-3. Possible interpretations of this result are presented.