Symbol Digit Modalities Test: Regression-Based Normative Data and Clinical Utility

Objective The purpose of this study was to provide regression-based normative data for the written, oral, and incidental recall trials of the Symbol Digit Modalities Test (SDMT). Method Regression-based normative equations for the written and oral trials were derived from 536 healthy men and women between the ages of 18 and 91. Normative equations for the incidental recall trial are provided for a subset of the normative sample (age range = 60–91). The clinical utility of the newly developed norms was examined by comparing mean performance and rates of impaired scores for participants with traumatic brain injury (TBI), mild cognitive impairment (MCI), and dementia. Within-group analyses were used to compare the new norms to the original published norms. Results Age, education, and sex were all significant predictors of written trial performance, age and education were significant predictors of oral trial performance, and only age predicted incidental recall trial performance. As expected, the TBI group demonstrated the highest rates of impaired performance on both written and oral trials. Participants with dementia showed the highest rate of impaired scores on the incidental recall trial, followed by participants with amnestic MCI. Compared to traditional norming methods, the regression-based norms classified more clinical participants as impaired on both the written and oral trials. Conclusions Comprehensive regression-based normative equations with demonstrated clinical utility are provided to improve the detection of cerebral dysfunction using the SDMT. A calculator with the normative equations is provided so that raw scores can be easily converted to demographically-corrected standardized scores.

Wait, There’s a Baby in this Bath Water! Update on Quantitative and Qualitative Cut-Offs for Rey 15-Item Recall and Recognition

Objective Evaluate the effectiveness of Rey 15-item plus recognition data in a large neuropsychological sample. Method Rey 15-item plus recognition scores were compared in credible (n = 138) and noncredible (n = 353) neuropsychology referrals. Results Noncredible patients scored significantly worse than credible patients on all Rey 15-item plus recognition scores. When cut-offs were selected to maintain at least 89.9% specificity, cut-offs could be made more stringent, with the highest sensitivity found for recognition correct (cut-off ≤11; 62.6% sensitivity) and the combination score (recall + recognition – false positives; cut-off ≤22; 60.6% sensitivity), followed by recall correct (cut-off ≤11; 49.3% sensitivity), and recognition false positive errors (≥3; 17.9% sensitivity). A cut-off of ≥4 applied to a summed qualitative error score for the recall trial resulted in 19.4% sensitivity. Approximately 10% of credible subjects failed either recall correct or recognition correct, whereas two-thirds of noncredible patients (67.7%) showed this pattern. Thirteen percent of credible patients failed either recall correct, recognition correct, or the recall qualitative error score, whereas nearly 70% of noncredible patients failed at least one of the three. Some individual qualitative recognition errors had low false positive rates (<2%) indicating that their presence was virtually pathognomonic for noncredible performance. Older age (>50) and IQ < 80 were associated with increased false positive rates in credible patients. Conclusions Data on a larger sample than that available in the 2002 validation study show that Rey 15-item plus recognition cut-offs can be made more stringent, and thereby detect up to 70% of noncredible test takers, but the test should be used cautiously in older individuals and in individuals with lowered IQ.

Differences between Early-Blind, Late-Blind, and Blindfolded-Sighted People in Haptic Spatial-Configuration Learning and Resulting Memory Traces

The roles of visual and haptic experience in different aspects of haptic processing of objects in peripersonal space are examined. In three trials, early-blind, late-blind, and blindfolded-sighted individuals had to match ten shapes haptically to the cut-outs in a board as fast as possible. Both blind groups were much faster than the sighted in all three trials. All three groups improved considerably from trial to trial. In particular, the sighted group showed a strong improvement from the first to the second trial. While superiority of the blind remained for speeded matching after rotation of the stimulus frame, coordinate positional-memory scores in a non-speeded free-recall trial showed no significant differences between the groups. Moreover, when assessed with a verbal response, categorical spatial-memory appeared strongest in the late-blind group. The role of haptic and visual experience thus appears to depend on the task aspect tested.

Sex Differences in Memory Estimates for Pictures and Words with Multiple Recall Trials

Undergraduate students (23 men and 23 women) provided memory performance estimates before and after each of three recall trials involving 80 stimuli (40 pictures and 40 words). No sex differences were found across trials for the total recall of items or for the recall of pictures and words separately. A significant increase in recall for pictures (not words) was found for both sexes across trials. The previous results of Ionescu were replicated on the first and second recall trials: men underestimated their performance on the pictures and women underestimated their performance on the word items. These differences in postrecall estimates were not found after the third recall trial: men and women alike underestimated their performance on both the picture and word items. The disappearance of item-specific sex differences in postrecall estimates for the third recall trial does not imply that men and women become more accurate at estimating their actual performance with multiple recall trials.

The Manipulation and Measurement of Task-specific Memory Self-Efficacy in Younger and Older Adults

Task-specific memory self-efficacy (TSMSE) was experimentally manipulated through provision of information about task difficulty, to determine its effect on free recall for 56 older (age 63-86) and 56 younger (age 16-25) adults. The implications of using prediction-based measures of TSMSE were addressed. After completing one recall trial of a list of 20 words, half the participants were told a second list comprised more difficult words; the others were told the second list would be similar to the first they had received. Free recall and TSMSE were measured before and after this manipulation. The manipulation reduced TSMSE for participants expecting a harder list of words, but not differently for younger compared with older adults. Younger and older adults’ recall declined at the second recall trial, but there was no difference between those expecting a harder list and those expecting a similar list. Recall was predicted by domain-specific memory self-efficacy as well as a traditional measure of TSMSE. The study demonstrated the malleability of memory self-efficacy, but called into question assertions about its salience as a mediator of older adults’ poorer memory performance.

Fluctuations in Mood State and Learning and Retrieval

The present study investigated whether learning and retrieval are associated with changes in mood state. 50 college students (20 men and 30 women) were assigned to one of five treatment conditions: Happy-Happy, Sad-Sad, Neutral-Neutral, Happy-Sad, and Sad-Happy Mood was induced via the Velten procedure. During the first mood-induction phase, students were exposed to a serial-learning task and recall trial, followed by a digit-symbol task. In the next phase, students were given a 5-min. muscle-relaxation exercise and a 5-min. distracting task. In the final phase, students underwent a second mood-induction phase, and a subsequent recall trial and digit-symbol task. Analyses indicated that recall was significantly greater in the Happy-Happy and Sad-Sad groups. Findings for the Neutral-Neutral group were mixed. Results are discussed in terms of support for the concept of context-related, mood-state-dependent recall.