Cross-cultural effect on suboptimal effort detection: an example of the Digit Span subtest of the WAIS-III in Taiwan.

Suppressed Digit Span performance has been proposed as an embedded indicator for suboptimal effort detection in neuropsychological evaluations in Western societies, particularly in the USA. However, its effectiveness in Chinese countries remains unexplored. The purposes of this study were first to explore normative Digit Span performance patterns between the Taiwan and American standardization samples, then to examine performances of patients with traumatic brain injury and with psychiatric diseases on the embedded measures (the Digit Span Scaled Score, Vocabulary minus Digit Span difference score, Reliable Digit Span, and the longest string of digits forward and backward) through retrospective data analysis. The normative Digit Span performance differs between the two cultural populations. Although litigating and nonlitigating participants perform differently on these measures, further prospective studies are needed to explore this issue with comprehensive external corroborating validity data.