Incidental Learning During Rapid Information Processing on the Symbol-Digit Modalities Test

Abstract

The Symbol--Digit Modalities Test (SDMT) is widely used to assess processing speed in MS patients. We developed a computerized version of the SDMT (c-SDMT) that scored participants' performance during subintervals over the course of the usual 90-s time period and also added an incidental learning test (c-ILT) to assess how well participants learned the symbol-digit associations while completing the c-SDMT. Patients with MS (n = 65) achieved lower scores than healthy controls (n = 38) on both the c-SDMT and c-ILT, and the scores on the two tests were correlated. However, no increase in the rate of item completion occurred for either group over the course of the c-SDMT, and the difference between groups was the same during each subinterval. Therefore, it seems implausible that controls completed more items on the c-SDMT because they were more adept at learning the symbol-digit associations as the test ensued. Instead, MS patients' poorer incidental learning performance appears to reflect the greater attentional burden that tasks requiring rapid serial processing of information impose upon them.

Sensorimotor integration assessment by the Symbol-Digit modalities test in patients with Parkinson’s disease

“…Our findings fit in part with findings by Denney et al, 3 on a computerised version of the SDMT. While incidental memory could be employed to learn symbol-digit pairs during the test, the time-constrained nature of the test could lead the participant to favour fast saccadic eye movements to the key area as the optimal strategy.…”

“…Incidental learning refers to the non-intentional memory of information that subjects are not asked to recall. 3 In healthy adults, the contribution of incidental learning performance on the SDMT has been modest (and secondary to processing speed). 4 In patients with multiple sclerosis, incidental learning was found to have minimal impact on the patients' performance on the SDMT within the allotted 90 seconds.…”

“…4 In patients with multiple sclerosis, incidental learning was found to have minimal impact on the patients' performance on the SDMT within the allotted 90 seconds. 3 We sought to explore if the technique by which Parkinson's disease (PD) patients complete the SDMT, as evidence by concomitant examination of eye movements, underlies the observed practice effect.We recently recruited patients with PD as well as healthy controls as part of a larger study. 5 In brief, 11 patients with PD and mild cognitive impairment (PD-MCI), 13 PD patients with normal cognition (PD-N) and 13 healthy controls (NC), matched for age, gender and education, were recruited.…”

“…4 In patients with multiple sclerosis, incidental learning was found to have minimal impact on the patients' performance on the SDMT within the allotted 90 seconds. 3 We sought to explore if the technique by which Parkinson's disease (PD) patients complete the SDMT, as evidence by concomitant examination of eye movements, underlies the observed practice effect.…”

Brain connectivity and cognitive processing speed in multiple sclerosis: A systematic review

“…Deficits in PS may have a broad influence on cognitive performance in people with MS. Indeed, memory and learning impairment is associated with impaired PS function [10][11][12]. Similarly, working memory and attention functions were predicted by performance in PS tasks that were also observed to be the best measure to discriminate people with MS from healthy controls [13][14][15][16][17].…”