Study of the Cognitive and Neurophysiological Effects of the Activ4Brain Program for Older Adults

Executive function will be assessed with the Multitasking test from the CANTAB Research Connect (Cambridge Cognition Ltd) - 3-months score change in MTT Multitasking cost (median). The score is calculated by subtracting the median latency of response during single task block(s) from the median latency of response during multitasking block(s). A positive score indicates that the subject responds more slowly during multitasking blocks and indicates a higher cost of managing multiple sources of information. Lower values are associated with better executive function.

Working memory will be assessed with the Spatial Working Memory (SWM) test from the CANTAB Research Connect (Cambridge Cognition Ltd)- 3-months score change in SWM Between Errors: the number of times the subject incorrectly revisits a box in which a token has previously been found. Lower values are associated with better working memory abilities.

Auditory Verbal Learning Test (AVLT) - 3-months score change in Total Learning: the sum of words remembered across Trial 1 through Trial 5. Higher values represent better memory abilities.

Sustained attention will be assessed with the Rapid Visual Information Processing test from the CANTAB Research Connect (Cambridge Cognition Ltd) - 3-months score changes in RVPA (subject's sensitivity to the target sequence). Higher values represent better sustained attention scores.

Processing speed will be assessed with the Rapid Visual Information Processing test from the CANTAB Research Connect (Cambridge Cognition Ltd) - 3-months score change in RVP Median Response Latency (median response latency on correct trials). Lower values represent faster processing speed.

Processing speed will be assessed with the Multitasking test from the CANTAB Research Connect (Cambridge Cognition Ltd) - 3-months score change in MTT Incongruency cost (difference between the median response latency on the congruent versus incongruent trials). A lower incongruency cost indicates that the subject processes conflicting information faster.

Change in event-related potentials evoked during a reinforcement learning task are assessed using amplitude (microV) measures of event-related potentials recorded using a 64-channel Neuroscan system (Compumedics EUROPE GmbH) with scalp electrodes placed according to the International 10-20 electrode system (500 Hz sampling rate).

Amplitude of task-related pupil responses during cognitive task performance are assessed using pupil size data obtained with an eye tracking system recorded during a reinforcement learning task. Amplitude of pupil responses are measured in normalized units as percentage of the mean pupil size for each participant.

Task-related heart rate responses that occur during a reinforcement learning task are calculated from the electrocardiogram recorded with bipolar electrodes attached to the participants' chest. Task-related heart rate responses are measured as changes in cardiac interbeat-interval associated with task events.

3-month change in Mean RR (ms), SDNN (ms), RMSSD (ms).

3-month change in VLF (ms^2), LF (ms^2), and HF (ms^2).

Changes in concentration of inflammatory blood biomarkers are assessed in blood samples collected from venous blood (15 ml) in a fasting state, in the morning. Plasma samples will be quantified by ELISA for Interleukin (IL)-6 (pg/ml), IL-1β (pg/ml), Tumor Necrosis Factor (TNF)-α (pg/ml), Interferon(IFN) -γ (pg/ml), IL-17, (pg/ml).

Changes in concentration of anti-inflammatory biomarkers are assessed in blood samples collected from venous blood (15 ml) in fasting state, in the morning. Plasma samples will be quantified by ELISA (Thermofisher, UK) for IL-1Ra (pg/ml), IL-10 (pg/ml).

Changes in concentration of Vascular Endothelial Growth Factor-D (VEGF-D) are assessed in blood samples collected from venous blood (15 ml) in fasting state, in the morning. Serum samples will be quantified by ELISA for VEGF-D (pg/ml).

Changes in concentration of Insulin-Like Growth Factor 1 (IGF-1) are assessed in blood samples collected from venous blood (15 ml) in fasting state, in the morning. Serum samples will be quantified by ELISA for IGF-1 (ng/ml).

Changes in concentration of Neurotrophic Factors are assessed in blood samples collected from venous blood (15 ml) in fasting state, in the morning. Serum samples will be quantified by ELISA for Brain-Derived Neurotrophic Factor (BDNF)(ng/ml) and Glial cell line-Derived Neurotrophic Factor (GDNF)(ng/ml).

Changes in concentration of Irisin (pg/ml) are assessed in blood samples collected from venous blood (15 ml) in fasting state, in the morning. Serum samples will be quantified by ELISA.

Adherence to the intervention protocols is assessed by evaluating the attendance rates (percentage of intervention sessions that were attended per participant).

Retention is quantified at the end of the study from dropout data: percentage of participants that terminated the intervention and completed the follow-up testing procedures in each group.

Program acceptability measured with custom made acceptability scale applied to the Activ4Brain and Aerobic Exercise groups. The scale is composed of 4 items and the responses are recorded on a scale ranging from 1 to 5 where larger values are associated with higher acceptability. The acceptability score is calculated as the average score of the 4 items.

Usability of the Activ4Brain cognitive training system measured with the System Usability Scale (SUS) applied to the Activ4Brain group. SUS is composed of 10 items, each measured on a scale from 1 to 5, and yields a single number representing a composite measure of the overall usability of the system being studied. Each item's score contribution ranges from 0 to 4. For items 1, 3, 5, 7, and 9 the score contribution is the scale position minus 1. For items 2, 4, 6, 8 and 10, the contribution is 5 minus the scale position. The sum of the scores is then multiplied by 2.5 to obtain the overall value of System Usability. SUS scores have a range of 0 to 100.

Peak oxygen uptake capacity (VO2 peak) measured in mL/min/Kg, with a submaximal incremental cycle ergometry test (Lode- Excalibur, Netherlands), before and after the intervention. Following a warm-up period, participants started the testing phase with an initial load of 50 watts for women and 75 watts for men33. The load is increased by 25 watts at every three-minute intervals. The test continues at 60-70 rpm and is completed once participants achieve 85% of their predicted maximal heart rate, as determined by the Tanaka Formula.

Changes in body composition is measured for total body mass (kg), fat mass (kg), fat free mass (kg) by bioimpedance.

3-months change in body mass index: weight and height will be combined to calculate BMI in kg/m^2).

3-months change in Phase Angle (°) calculated automatically by the Inbody 770 device (Biospace) with following formula (°) = (reactance/resistance) × (180/π).