Music as a mnemonic strategy to mitigate verbal episodic memory in Alzheimer's disease: Does musical valence matter?

Introduction: Music is increasingly used to improve cognition in clinical settings. However, it remains unclear whether its use as a mnemonic strategy is effective in Alzheimer's disease (AD). The present study aimed at determining whether a musical mnemonic might mitigate patients' learning of new verbal information and at exploring the effect of factors such as retention delay and emotional valence of the musical excerpt used. Method: 13 patients with AD and 26 healthy comparisons (HC) with a low musical expertise were included. They learned texts about everyday life themes that were either set to familiar instrumental music, which was positively- or negatively-valenced, or spoken only. Immediate and delayed recalls (after 10 min and 24 hours) were measured. Results: Main results showed that (i) HC demonstrated better verbal episodic memory performance than participants with AD; (ii) participants with AD encoded texts paired with positively-valenced music better than texts paired with negatively-valenced music; (iii) participants with AD recalled sung texts better than spoken texts (after 10 min and 24 hours), regardless of musical valence while HC displayed better recall for texts paired with positively-valenced music. Conclusions: Musical mnemonics may help people with AD learn verbal information that relates to their daily life, regardless the musical expertise of the patients. This result gives promising clinical insights showing that music processing is robust to brain damage in AD. Possible hypotheses explaining the effectiveness of musical mnemonics in AD regardless the musical valence are discussed (e.g., different processing between musical and spoken conditions; disappearance of the positivity bias and implications with respect to the underlying socio-emotional selectivity theory).

Is music a memory booster in normal aging? The influence of emotion.

Age-related differences in episodic memory have been explained by a decrement in strategic encoding implementation. It has been shown in clinical populations that music can be used during the encoding stage as a mnemonic strategy to learn verbal information. The effectiveness of this strategy remains equivocal in older adults (OA). Furthermore, the impact of the emotional valence of the music used has never been investigated in this context. Thirty OA and 24 young adults (YA) learned texts that were either set to music that was positively or negatively valenced, or spoken only. Immediate and delayed recalls were measured. Results showed that: (i) OA perform worse than YA in immediate and delayed recall; (ii) sung lyrics are better remembered than spoken ones in OA, but only when the associated music is positively-valenced; (iii) this pattern is observed regardless the retention delay. These findings support the benefit of a musical encoding on verbal learning in healthy OA and are consistent with the positivity effect classically reported in normal aging. Added to the potential applications in daily life, the results are discussed with respect to the theoretical hypotheses of the mechanisms underlying the advantage of musical encoding.