Fig. 2 Musician status in the digit span backward task.
The results showed that participants performed better in the Digits Backward task when both receptors were activated compared to when GRs only were activated (P<0.01).
The digit span backward task showed a main effect of musician status, F 1, 148) = 6.07, p = 0.015, and a small effect size, η2 = 0.04.
FEM patients had poorer verbal working memory compared to HCs on the digit span backward task, with medium effect (η 2 = 0.06) for FEM patients without a previous history of untreated manic symptoms.
Consistent with the previous findings for the digit span backward task, the results of a 2 × 2 (musician status [musician, non-musician] × language status [bilingual, monolingual]) between-subjects ANOVA showed a main effect of musician status, F 3, 96) = 7.68, p = 0.007, η2 = 0.074, with musicians (M mus = 8.97) outperforming non-musicians (M n-mus = 7.44) on the digit span backward.
Of particular note, performance on the digit backward task (working memory) was significantly and positively associated with left and right hippocampal volumes measured by manual tracing and with automatic segmentation.
Multiple regression analyses showed that performance on the digits backward task, which involves recalling strings of numbers of increasing length in reverse order, was significantly associated with hippocampal volume for both measures.
These analyses (Table 3) revealed that in these smaller samples affording less statistical power an association between performance in the digits backward task and hippocampal volume was only detectable in males and for the right hippocampus for both methodological methods.
One cognitive task, the Digit Backward Task, was not analyzed because some participants applied a strategy that defeated the idea of the test.
However, there was no significant correlation between the deception task index and performance of the digit span (backward) task (r = –0.245, P = 0.179).
