Effects of Heart Rate Oscillations During Meditation on Plasma Biomarkers of Alzheimer's Disease
Phase: NA
Conditions: Alzheimer Disease
Sponsor: University of Southern California

Study Protocol 
 
Title: Effects of Heart Rate Oscillations During 
Meditation on Plasma Biomarkers of Alzheimer's 
Disease 
 
NCT number: NCT06210035 
 
IRB approval date: 5/25/2023 
 
Uploaded date: 10/27/2025 
 
 

Research Background 
 
Cross-sectional studies suggest that meditation practices are associated with slower 
brain aging and improvements in early biomarkers of Alzheimer’s disease (AD). 
However, the underlying mechanisms remain unclear. Most research has focused on 
the mental training aspects of meditation (e.g., paying attention to the present moment) 
and linked them to health outcomes. By contrast, the physiological changes that occur 
during meditation (e.g., heart rate oscillations, breathing rate) and their influence on 
health outcomes have been largely overlooked. 
 
During some meditative practices, breathing slows down, which induces large 
oscillations in heart rate at the breathing frequency. In our previous HRV-ER trial 
(NCT03458910), a 4-week daily intervention designed to induce high-amplitude heart 
rate oscillations via slow-paced breathing significantly reduced plasma amyloid beta 
(Aβ)42 and Aβ40 levels associated with AD. 
 
 
Research Objectives 
 
Based on our prior findings, the present study aims to separate out the mental training 
and physiological aspects of meditation to better understand their differential effects on 
plasma Aβ levels. We will examine how two types of meditation practices (with or 
without slow breathing) affect plasma Aβ levels compared with a no-intervention control 
group. We will also assess the effects of these practices on emotional well-being, given 
that various types of meditation improve well-being. 
 
Healthy adults aged 18-35 who meet all eligibility criteria will be invited to this study. 
Participants will be asked to engage in one week of daily meditation practice or no-
intervention control task at home. They will also be asked to visit the lab twice, once 
before and once after the intervention, to provide blood samples to assess plasma Aβ 
levels and to complete emotion questionnaires and memory tests. 
 
 
 

Methods and Design 
 
Lab Visit 1 (around 1.5 hours) 
1) Consent 
At the beginning of this visit, the researchers will provide detailed information about 
the study. Participants will then be asked to sign the consent form on DocuSign. 
When they sign, participants will have the opportunity to download a copy of the 
signed consent form for their record.  
 
2) Administer questionnaires 
Participants will be asked to complete the following questionnaires at the Emotion & 
Cognition Lab: 
• Profile of Mood States (POMS) 
• Depression Anxiety Stress Scales – Short Form (DASS-21)  
• Five Facet Mindfulness Questionnaire 
• Demographic information 
 
3) Blood draw 
Phlebotomists will collect blood samples up to 30 mL via venipuncture. Note that 
blood draw volume for blood donation in the US is 1 pint (~450 mL); thus, 30 mL 
should be safe for participants. Fasting is not required for the blood draw. 
 
4) Measure resting heart rate 
Give the participant devices and explain how to use them. The devices include a 
laptop with a customized meditation app, USB-module and an ear sensor that clips 
onto the earlobe and measures heart rate.1). Using the devices, the participant will 
be asked to measure their heart rate for 5 min. During the 5-min resting state, they 
will be asked to sit in a chair with palms up, both feet flat on the floor, back straight, 
knees 90-degree angle, and closed eyes.  
 
5) Paced breathing 
Next, the app will ask participant to do 5 minutes of paced breathing at 15 breaths 
per minute by following audio cues. The participant will be asked to inhale when the 
ball ascends and exhale when it descends. This controlled breathing at around a 
normal breathing pace will allow us to assess baseline individual differences in heart 
rate spectral frequency with breathing rates controlled. 
 
6) Intervention instructions 
The app will randomly assign participant to one of the three conditions (belly-focus 
concentration meditation, belly-focus concentration meditation with slow breathing, 
no-intervention control). The experimenter will go over the instructions below and 
have them try the assigned practice for 20 minutes.  
 
Instructions for the belly-focus meditation: 

The app will show, “You will be asked to sit quietly to meditate for 20 minutes while 
your heart rate is recorded. During this time, you will listen to a guided meditation 
(pre-recorded by a meditation expert) to help you focus on the sensations around 
the belly. Please remember that it is normal for the mind to wander. When this 
happens, gently bring your attention back to your belly.” 
 
Audio guided meditation 
At the beginning of the session: 
• Welcome, please sit in a comfortable position in a chair or on a cushion with 
your back and neck upright and yet comfortable and gently close your eyes. If 
you wear glasses, feel free to take them off. 
• Keep your mouth gently closed and focus your entire attention… entire 
attention on your belly.  
• Remain aware, aware of every breath coming in, every breath coming out. 
• On the inhale, allow your belly to receive your breath, on the exhale allow the 
belly to contract 
• Notice the sensations around the belly as the breath comes in and out.  As 
your breath flows in, feel it move down into your belly. Please observe how 
breathing makes your belly move. Whatever sensations arise, keep your 
attention here, noticing the arising and passing of sensation from moment to 
moment. 
• As you inhale, feel your belly expanding and as you exhale feel your belly 
contracting. Noticing moment to moment whatever sensations are present 
here in the belly.  
• As you meditate, many thoughts, feelings, images, and memories may come 
up. Welcome, all that arises. Letting them rise and fall, staying with the 
sensations of the breath expanding and contracting the belly. 
At 5 minutes: 
• If you find yourself in conversation with a thought or feeling, simply 
acknowledge this is happening, meet yourself kindly, and bring attention 
gently back to the sensations in the belly.  
At 8 minutes: 
• Whatever sensations arise, just observing. Observe how long the sensation 
lasts, how it changes with each passing moment. It may become stronger for 
some time, but sooner or later it passes away. No sensation is eternal, each 
arising and passing away.  It is the same with any sensation, whether it be a 
tingling, an itching, warmth, coolness, or vibration, heaviness; simply observe 
whatever sensation is present, noticing how they change moment to moment. 
At 12 minutes: 
• It’s quite normal for the mind to wander, if and when you notice your mind 
wandering, gently bring your attention back to the sensations of breath in the 
belly right here and now, what sensations are present? 
At 15 minutes: 
• Noticing where the mind is now, and gently bringing attention back to the 
sensations of breath and the belly. Moment to moment what sensations are 

present in the belly.  Each moment of the inhalation … exhalation, what 
sensations are present now? 
At the end: 
• This is the end of the session. Close your practice by setting an intention to 
stay connected to your body as you move slowly out of the meditation. 
 
Instructions for the belly-focus meditation with slow breathing: 
The app will show, “You will be asked to sit quietly to meditate for 20 minutes while 
your heart rate is recorded. During this time, you will listen to a guided meditation 
(pre-recorded by a meditation expert) to help you focus on the sensations around 
the belly. You will also be asked to breathe slowly during the entire meditation 
session. Please remember that it is normal for the mind to wander. When this 
happens, gently bring your attention back to the upper lip area.” 
 
Audio guided meditation 
At the beginning of the session: 
• Welcome, please sit in a comfortable position in a chair or on a cushion with 
your back and neck upright and yet comfortable and gently close your eyes. If 
you wear glasses, feel free to take them off. 
• Keep your mouth gently closed and focus your entire attention… entire 
attention on your belly. 
• Remain aware, aware of every breath coming in, every breath coming out. 
• On the inhale, allow your belly to receive your breath, on the exhale allow the 
belly to contract. 
• Take long slow breaths as I guide you. Inhale for a count to 5 and exhale for a 
count to 5. Breathe slowly and gently at this pace during the entire meditation 
exercise. I’ll count with you for the first few breaths. Then you can count on 
your own. Inhale, 2, 3, 4, 5, exhale 2, 3, 4, 5. Inhale, 2, 3, 4, 5, exhale 2, 3, 4, 
5. Continue breathing this way on your own. 
• Notice sensations around the belly as the air moves in and out. As your 
breath flows in, feel it move down into your belly. Please observe how 
breathing makes your belly move. Whatever sensations arise, keep your 
attention here, noticing the arising and passing of sensation from moment to 
moment. 
• As you inhale, feel your belly expanding and as you exhale feel your belly 
contracting. Noticing moment to moment whatever sensations are present 
here in the belly. 
• As you meditate, many thoughts, feelings, images, and memories may come 
up. Welcome, all that arises. Letting them rise and fall, staying with the 
sensations of the breath expanding and contracting the belly. 
At 5 minutes: 
• If you find yourself in conversation with a thought or feeling, simply 
acknowledge this is happening, meet yourself kindly, and bring attention 
gently back to the sensations in the belly. Remember to breathe slowly and 
gently for a count of 5 while inhaling and a count of 5 while exhaling. 
At 8 minutes: 

• Whatever sensations arise, just observing.  Observe how long the sensation 
lasts, how it changes with each passing moment. It may become stronger for 
some time, but sooner or later it passes away. No sensation is eternal, each 
arising and passing away.  It is the same with any sensation, whether it be a 
tingling, an itching, warmth, coolness, or vibration, heaviness; simply observe 
whatever sensation is present, noticing how they change moment to moment. 
Remember to breathe slowly and gently for a count of 5 for each inhalation 
and a count of 5 for each exhalation during the remaining session. 
At 12 minutes: 
• It is normal for the mind to wander, if and when you notice your mind 
wandering, gently bring your attention back to the sensations in the belly right 
here and now, what sensations are present? Remember to breathe slowly 
and gently. 
At 15 minutes: 
• Noticing where the mind is now, and gently bringing attention back to the 
sensations of breath and the belly.  Moment to moment what sensations are 
present in the belly.  Each moment of the inhalation … exhalation, what 
sensations are present now? 
At the end: 
• This is the end of the session. Close your practice by setting an intention to 
stay connected to your body as you move slowly out of the meditation. 
 
Instructions for the no-intervention control condition: 
The app will show, “You will be asked to sit quietly for 20 minutes while your heart 
rate is recorded. Please feel free to do whatever you would like to do (e.g., use your 
phone or computer, read a book, watch TV, listen to music) as long as your activity 
does not involve head motion.” 
 
Before each practice session, participants in all conditions will view 6 images from 
the Nencki Affective Picture System (NAPS; uploaded on section 21.2) and rate 
them on a scale of 1-9 (1 = very negative to 9 = very positive, with 5 = neutral). At 
the post-intervention lab visit (i.e., Lab Visit 2), they will be given memory tests for 
these images (see below for more details). 
 
One week intervention at home 
Participants will be asked to engage in the assigned practice for 40 minutes (20 min x 
two times) each day for a week.  
 
Lab Visit 2 (around 1 hour) 
Participants will be asked to return their devices and complete the assessments listed in 
Lab Visit 1 Steps 2-5. In addition, participants will complete a free recall test in which 
they will describe as many images as they can that were viewed right before each 
meditation practice in the past week. They will also complete a recognition memory test 
in which they will be given 3 response options for each image; Remember, Know and 
New (Remember = “I vividly remember,” Know = “I have a sense of familiarity with the 
image, New = the image was not seen before”).