Results
Table 2 presents a summary of musical performance and working memory measures for all participants.
Table 2
Summary of Musical Performance and Working Memory Measures
| M | SD | |
| Musical performance (%TEP) | ||
| Normal feedback | 13.40 | 7.19 |
| 150 ms DAF | 17.34 | 9.84 |
| 250 ms DAF | 22.14 | 9.29 |
| 350 ms DAF | 19.25 | 8.09 |
| Working memory | ||
| Reaction time (ms) | 700.32 | 22.96 |
| Accuracy (% correct) | 88 | 7 |
Musical Performance
%TEP was lowest for normal auditory feedback, reaching a peak at 250 ms delay. Given that our novel method yields a similar relationship between musical performance and delay interval as Gates et al.’s seminal paper (1974), we suggest that %TEP has at least strong face validity as a measure of musical performance. Independent samples t-tests found was no significant effect on musical performance under any feedback condition from sex (ps > .25), dominant hand (ps > .5), or ability to read music (ps > .25), though as expected, musical performance was significantly better under all feedback conditions for pianists than for non-pianists (ps < .05). Nevertheless, the improvement by pianists was consistent – between 7.52 to 8.16 %TEP – across all feedback conditions; in other words, piano playing did not exhibit an interaction with feedback condition (see Figure 2).Figure 3
Musical Performance for each Feedback Condition
DAF Effect on Musical Performance
Our interest is the effect of DAF on musical performance, and not musical performance under DAF per se. Thus, we quantify DAF effect as the %TEP at no delay subtracted from the %TEP at 250 ms DAF since this was the maximal impairment interval. The mean DAF effect was 8.74 %TEP (SD = 7.09). There was no significant effect of sex ( Mmale = 9.02, Mfemale = 8.56, t(21) = -0.15, p = .884), ability to read music (Myes = 9.02, Mno = 8.53, t(21) = -0.16, p = .875), piano playing ( Myes = 8.74, Mno = 8.75, t(21) = 0.01, p = .996), or dominant hand (Mright = 8.19, Mleft = 12.40, t(2.11) = 0.51, p = .657). Moreover, there was no significant correlation between DAF effect and years of musical instruction (r(21) = -.12, p = .596) or reference tempo (r(21) = -.15, p = .507)
Working Memory
Mean N-back reaction time for all participants was 700.32 ms (SD = 22.96) and accuracy was 88% (SD = 7). Interestingly, reaction time was significantly faster for women than for men (Mfemale = 691.92, Mmale = 713.39, t(17.96) = -2.87, p = .010), though men were more accurate but not significantly so (
Mfemale
= 86.29,
Mmale
= 91.33, t(21) = -1.86, p = .077). There was no effect on either reaction time or accuracy from playing piano, being able to read music, or dominant hand (ps > .1). Moreover, there was no significant correlation between either measures and years of musical instruction (|rs| < 0.15, ps > .5).Working Memory and DAF Effect
The main concern of this study is the relationship between working memory and DAF effect on musical performance; we hypothesised that participants with better working memory would be less affected by DAF. Figures 3 and 4 present the scatterplots for DAF effect against N-back accuracy and reaction time. We observed a moderate negative correlation between DAF effect and N-back accuracy (r(21) = -.36, p = .044), and a weak positive correlation with N-back reaction time (r(21) = .14, p = .260) (ps, one-tailed). Although correlation with reaction time was not significant, taken as a whole these results suggest that better working memory is correlated with the ability to overcome the effect of DAF.Figure 4
Scatterplot of DAF Effect against N-back Accuracy
Figure 5
Scatterplot of DAF Effect against N-back Reaction Time
Finally, we performed a multiple linear regression to determine if working memory or any other variables were predictors of DAF effect. Sex, ability to read music, piano playing, years of musical instruction, reference tempo, N-back accuracy, and N-back reaction time were entered into the model. Although the model did not reach significance (F(7,15) = 1.29, p = .33), it did generate an R2 = .37. Interestingly, of all the entered variables, only N-back task accuracy reached significance with p = .029, and it also had the biggest effect size, with standardised β = -.57 (see Table 3). No other entered variables were close to significance (ps > .15).
Table 3
Predictors of DAF Effect
| β | p | |
| Sex | 0.24 | .380 |
| Ability to read music | 0.47 | .166 |
| Piano playing | -0.16 | .683 |
| Years of musical instruction | -0.40 | .269 |
| Performance tempo | -0.33 | .161 |
| N-back accuracy | -0.57 | .029 |
| N-back reaction time | 0.34 | .210 |
Note. Standardised β.