The Power of Sound and Music Interventions for Older Adults With Mild Cognitive Impairment

Episodic Memory Assessed by the Cogstate Alzheimer's Battery

时间窗: Baseline and 4 weeks

The composite episodic memory score is calculated as a Z-score, representing the sum of the Z-scores across three Cogstate computerized assessments: One Card Learning, International Shopping List, and Delayed Recall. For each test, a Z-score is calculated relative to the first baseline assessment of all included subjects, using the formula (score - mean at first baseline assessment) / standard deviation at first baseline assessment. The composite Z-score is then calculated by summing these individual Z-scores. A composite Z-score of 0 corresponds to performance exactly at the study-sample mean at the first baseline assessment. Positive, or higher, composite Z-scores reflect better episodic-memory performance-they show how many standard deviations above the baseline mean the summed score lies. Conversely, negative, or lower, composite Z-scores reflect poorer episodic-memory performance, indicating how many standard deviations below the baseline mean the score falls.

Global Cognition Assessed by the Cogstate Alzheimer's Battery

时间窗: Baseline and Immediate after 4-week intervention

The composite global cognitive score is expressed as a Z-score obtained by summing the Z-scores from six Cogstate computerized assessments: Identification, Detection, One Card Learning, One Back, International Shopping List-Delayed Recall, and Groton Maze Learning. For each task, an individual Z-score is calculated with reference to the first baseline assessment of all enrolled participants using the formula (individual score - baseline mean) / baseline standard deviation. These task-specific Z-scores are then summed to yield the composite value. A composite Z-score of 0 denotes performance exactly at the study-sample mean at the first baseline assessment. Positive-or higher-composite Z-scores reflect better global cognitive performance because they indicate performance a given number of standard deviations above that first baseline mean, whereas negative-or lower-composite Z-scores reflect poorer performance by indicating the number of standard deviations below the mean.