Happy and sad judgements in dependence on mode and note density in patients with mild cognitive impairment and early-stage Alzheimer's disease.

Background: In Western cultures it has often been assumed that the experience of happy or sad emotions while listening to music is clearly correlated to the key (mode) and the tempo of the musical piece. Recent studies point towards more complex dependencies, but knowledge in this line of research is still very limited, especially regarding the experience of music for persons with memory-related disorders such as dementia.

Objective: This pilot study explores the emotional content of music for patients with mild cognitive impairment (MCI) and early-stage Alzheimer's disease (AD) and compares them to healthy subjects.

Methods: A new test was specifically designed for this study and presented to 10 patients with MCI diagnosis, 10 with AD diagnosis and 23 controls. The test comprised musical stimuli consisting of chords and short musical pieces in major and minor mode with variable note density (number of notes per second).

Results: In the current study no significant correlation between key and the attribution of 'happy' or 'sad' judgements to a musical piece could be found in all groups. Note density, however, was shown to exhibit a strong influence on happy/sad judgements in all groups.

Conclusion: Our findings indicate that the note density of a musical piece is much more important for happy/sad judgements than the key. Furthermore, the diagnosis MCI and early AD had no influence on the attribution of emotional expressions to musical pieces, corroborating recent findings of spared memory for music in these patient groups.