Memory for Music: Individual Intensive Musical Training in Alzheimer's Disease

ADAS-cog

ADAS-cog is a scale developed to assess the level of cognitive dysfunction in individuals with Alzheimer's disease. The standard ADAS-cog includes the following 11 subtests, with a total scoring range from 0 (no impairment) to 70 (most severe impairments): word recall (0-10); commands (0-5); naming (0-5); constructional praxis (0-5); ideational praxis (0-5); orientation (0-8); word recognition (0-12); remembering word recognition test instructions (0-5); spoken language ability (0-5); comprehension of spoken language (0-5); word-finding difficulty (0-5). The ADAS-cog score is based on the number of errors made within each subtest.

EEG-ERP N400 in response to music stimuli

Electroencephalography (EEG) is a non-invasive method of measuring brain activity. Electrical potential from the brain is measured through electrodes on a cap fitted on the head of the participant. Event-related potentials (ERPs) in response to music violations (unexpected notes in songs) will be analysed to indicate implicit memory for learned music. Generally, ERPs are measured by averaging the EEG signal over multiple repetitions of the same stimulus response. In this study, ERP analyses will focus on amplitude variation of the N400 component, which is a negative inflection of the EEG signal around 400ms after the onset of a stimulus (here an unexpected note in a song presented via audio recording). It is measured in µV and results in a continuous variable. Because the direction of the N400 is negative, and a stronger response indicates better music memory, lower amplitudes values are interpreted as more favourable outcomes.

Mood

Self-reported mood at beginning and end of each training session, using a 5-point scale with emojis (icons of faces where 1=sad and 5=happy; higher values mean better outcome).

Sense of Familiarity with current song (Instructor)

Rated by intervention provider during the training session. Ratings for estimated Sense of Familiarity: 1 - None; 2 - Implicit memory, mere exposure effect; 3 - Weak familiarity; 4 - Familiarity; 5 - Weak recollection; 6 - Recollection. For this study, a score of 4 or above is considered as the threshold to determine familiarity-based recognition.

Sense of Familiarity with current song (External Evaluator)

Rated by an external evaluator based on video recordings of training sessions. Ratings for estimated Sense of Familiarity: 1 - None; 2 - Implicit memory, mere exposure effect; 3 - Weak familiarity; 4 - Familiarity; 5 - Weak recollection; 6 - Recollection. For this study, a score of 4 or above is considered as the threshold to determine familiarity-based recognition.

Performance (chorus solo)

Performance (independent recall) of a learned song during solo performance, whether the participant needs full support / intermittent support / support in one syllable/word per line / is fully independent. Rated by an external evaluator based on video recordings of training sessions. Possible range 8-32, where highest is best.