A Multi-domain Intervention for Healthy Aging

Brain-Derived Neurotrophic Factor (BDNF)

BDNF levels detected in saliva

Cognitive functioning

Assessed using the Montreal Cognitive Assessment (MoCA) (Nasreddine et al., 2005), a widely used screening tool for cognitive impairment that evaluates multiple cognitive domains, including attention, executive functions, memory, language, visuoconstructional skills, conceptual thinking, calculations, and orientation. Description of the task: The MoCA consists of 30 items, covering various cognitive tasks such as word recall, trail-making, and visuospatial exercises. Unit of Measure: Raw score, ranging from 0 to 30, where higher scores indicate better cognitive functioning. A score below 26 typically indicates mild cognitive impairment. Interpretation: Higher scores reflect better cognitive performance. The measure is commonly used to detect cognitive deficits and track cognitive changes over time.

Fluid Intelligence

Assessed with computerized Matrix Reasoning (Condon \& Revelle 2014; Chan \& Kosinski, 2015), a test that contains stimuli that are similar to those used in Raven's Progressive Matrices. Task Description: The stimuli are 3 × 3 arrays of geometric shapes with one of the nine shapes missing. Participants are instructed to identify which of the six geometric shapes presented as response choices will best complete the stimuli. In each round the stimulus disappears after 120 s, leaving only the response options visible for the participant. Unit of Measure: The score is calculated as a standardized z-score, with a mean of 0 and no fixed minimum or maximum value. Scores can be both positive or negative, depending on the participant's performance relative to the sample distribution. Interpretation: Higher positive scores indicate better-than-average performance in reasoning ability, while negative scores indicate below-average performance. This measure is suitable for evaluating individual

Hearing Threshold

Assessed using a liminal tonal audiometric test, which determines the participant's minimum acoustic intensity perceivable at different tonal field frequencies. Description of the task: Participants are tested across a range of frequencies in a soundproof booth to identify the lowest intensity level at which they can detect a tone. Unit of Measure: Hearing threshold in decibels hearing level (dB HL), measured for each frequency. Lower thresholds (i.e., lower dB HL values) indicate better hearing sensitivity. Interpretation: Lower dB HL values indicate better hearing ability. The results are used to identify any hearing loss and its severity at specific frequencies.

Physical activity

Assessed using the Global Physical Activity Questionnaire (GPAQ), developed by Armstrong \& Bull (2006) for the World Health Organization (WHO) to measure physical activity levels across different domains of daily life. Description of the task: The GPAQ collects self-reported information on physical activity in three domains: Work-related physical activity Travel to and from places (active transport) Recreational physical activity It also includes a section on sedentary behavior. Unit of Measure: Physical activity is reported in Metabolic Equivalent of Task (MET) minutes per week. Sedentary behavior is reported in minutes per day spent sitting. Interpretation: Higher MET minutes indicate greater physical activity levels, while higher sedentary minutes indicate lower activity and greater sedentary behavior.

Cognitive Reserve

Assessed using the Cognitive Reserve Index Questionnaire (CRIq), developed by Nucci, Mapelli \& Mondini (2012), a tool designed to estimate an individual's cognitive reserve based on their lifetime activities. Description of the task: The CRIq collects self-reported information across three domains: Education (CRI-E): Years of formal education and training. Working activity (CRI-W): Type and duration of work experience, categorized by cognitive demand. Leisure time activities (CRI-L): Participation in cognitively stimulating activities during leisure time (e.g., reading, social engagement, cultural activities). Unit of Measure: The questionnaire provides a total Cognitive Reserve Index (CRI) score, along with sub-scores for each domain (CRI-E, CRI-W, CRI-L). The total score is standardized, with higher values indicating greater cognitive reserve. Interpretation: Higher CRI scores suggest a higher level of cognitive reserve, which is associated with better cognitive functioning and r

Melody Discrimination

Assessed using the Melody Discrimination Test (MDT), an adaptive task based on a three-alternative forced-choice (3-AFC) melodic discrimination paradigm, developed by Harrison et al. (2017). The test evaluates participants' ability to discriminate between similar melodies by identifying the melody with a single altered note. Description of the task: In each trial, participants hear three versions of the same melody. Two of the versions (lures) have the same interval structure, while the third version (the odd-one-out) contains a single altered note. Participants are required to identify the odd-one-out melody by first identifying the most similar pair and then selecting the melody that is different. The difficulty of the items is adaptively adjusted by manipulating the length of the melodies. In this study, the test consists of 18 items. Unit of Measure: Standardized z-score, with a mean of 0 and no fixed minimum or maximum value. Scores can be positive or negative, depending on the

Mistuning Perception

Assessed using the Mistuning Perception Test (MPT) (Larrouy-Maestri et al., 2019), which evaluates the ability to detect mistuning in musical extracts. Description of the task: In each trial, participants are presented with two versions of a musical excerpt-one "in tune" and one "out of tune"-and must identify the out-of-tune version. The stimulus material consists of short excerpts (6-12 s in length) from pop music performances (obtained from MedleyDB; Bittner et al., 2017) for which the vocal track was pitch-shifted relative to the instrumental tracks. Each musical extract has a vocalist singing the main melodic line and an instrumental accompaniment. Out-of-tune extracts are produced by adding a constant pitch shift to the vocal line Unit of Measure: Standardized z-score with a mean of 0, where scores can be positive or negative. Interpretation: Higher scores indicate better mistuning perception.