Acute Effects of a Single-Session Body Awareness Intervention on Cortical Activity and Interoceptive Accuracy

Official title

Investigation of the Acute Effects of a Body Awareness Application on Cortical Activity and Interoceptive Accuracy in Healthy Young Adults

Overview

This study will examine the immediate (acute) effects of a single, 30-minute body awareness session on brain activity and interoceptive accuracy in healthy young adults aged 18-25. Participants will be randomly assigned to one of two groups: an intervention group, which will complete a structured body awareness exercise based on Basic Body Awareness Therapy, or a control group, which will rest quietly for the same amount of time without any specific instructions. Before and after the session, brain activity will be recorded using a portable, 8-channel EEG device, and interoceptive accuracy will be measured with a heartbeat perception task, in which participants try to count their own heartbeats without checking their pulse. The main goal is to determine whether a single body awareness session produces measurable changes in EEG brain wave patterns (theta, alpha, beta, and gamma bands) and in the accuracy of heartbeat perception, and whether these two types of change are related to each other.

Detailed description

Body awareness is a multidimensional construct that involves conscious perception of posture, breathing, muscle tone, movement, balance, contact, and internal bodily sensations. It is closely related to interoception - the perception and interpretation of physiological signals arising from within the body. Prior research suggests that body-awareness-based approaches, such as Basic Body Awareness Therapy, can positively influence body awareness, body attitude, and psychophysiological function in various clinical populations. However, few studies have examined the acute neurophysiological effects of a single body awareness session in healthy young adults using portable, low-channel EEG systems, and the relationship between EEG changes and interoceptive accuracy remains insufficiently explored.

This study is designed as a two-arm, parallel-group, randomized controlled trial. Participants will be randomly assigned in a 1:1 ratio to either an intervention group or a control group. Randomization will be generated by an independent researcher not involved in data collection or intervention delivery, using a computer-based random number method; group allocation will be concealed using sequentially numbered, opaque, sealed envelopes opened only after baseline measurements are completed. Due to the nature of the intervention, participants and the person delivering the session cannot be blinded; however, researchers involved in EEG signal processing and interoceptive accuracy scoring will be blinded to group assignment where possible.

The intervention group will receive a single, approximately 30-minute structured body awareness session based on Basic Body Awareness Therapy principles, consisting of preparatory orientation, supine body scanning and contact awareness, breath awareness, slow symmetrical movement awareness, seated midline/postural awareness, standing weight-shift awareness, and a closing integration period. The control group will undergo a quiet/neutral resting session of equal duration and in the same environment, without any body-awareness-related instructions, in order to control for effects attributable to time, environment, rest, or eye closure alone.

In both groups, resting-state EEG will be recorded before and after the session using an 8-channel wireless EEG device (Enobio 8) at a 500 Hz sampling rate, following the international 10-20 system, with electrode sites covering frontal, sensorimotor, and parietal regions (Fz, FCz, Cz, C3, C4, Pz, P3, P4). EEG data will be preprocessed using standard steps including band-pass filtering (1-45 Hz), 50 Hz notch filtering, independent component analysis (ICA), artifact rejection, and common average referencing. Absolute and relative power in the delta, theta, alpha, beta, and gamma frequency bands will be calculated, with particular attention to frontal theta, alpha, and gamma activity, given their proposed associations with attention, internal focus, and relaxation.

Interoceptive accuracy will be assessed before and after the session using a heartbeat perception task based on the Schandry method, in which participants silently count perceived heartbeats over defined time intervals without taking their pulse; actual heartbeats will be recorded physiologically over the same intervals, and a normalized interoceptive accuracy score will be derived from the agreement between perceived and actual counts.

The primary outcome is the pre-to-post change in EEG frequency band power. The secondary outcome is the pre-to-post change in interoceptive accuracy score, and the relationship between EEG-based changes and interoceptive accuracy changes will also be examined. Sample size was determined via power analysis (G\*Power 3), based on effect sizes reported in prior heartbeat-evoked potential research, yielding a target of 42 participants per group (84 total) at α = 0.05 and 80% power, including an allowance for a 20% dropout rate. Statistical analysis will include mixed-design analyses (e.g., two-way mixed ANOVA or linear mixed models) to evaluate group × time interactions for EEG outcomes, and correlational analyses (Pearson or Spearman) to examine associations between EEG and interoceptive accuracy changes, with appropriate corrections for multiple comparisons across channels and frequency bands. The study will be conducted and reported in accordance with CONSORT guidelines for randomized controlled trials.

Interventions

• Other Basic Body Awareness Therapy Intervention
  A single \~30-minute body awareness session delivered in a quiet, well-ventilated room with minimal distraction. The session follows a structured sequence of low-intensity, pain-free, non-strenuous body awareness exercises performed in supine, sitting, and standing positions, guided verbally by a trained physiotherapist or researcher. The session focuses on conscious awareness of posture, contact points, breathing, and movement quality rather than physical performance, strength, or flexibility.
• Other No Intervention/Sham Comparator
  A single \~30-minute quiet resting session delivered in the same room and under the same environmental conditions as the intervention session. Participants will be asked to remain in a comfortable seated or supine position, close their eyes or fix their gaze on a stationary point, and rest quietly for the full duration. No specific breathing, body awareness, or movement instructions will be given. Participants will be informed that they may notify the researcher if they experience any discomfort

Primary outcome measures

• Change in EEG Theta Band Power [Time frame: Immediately before vs. immediately after the ~30-minute session]
• Change in EEG Alpha Band Power [Time frame: Immediately before vs. immediately after the ~30-minute session]
• Change in EEG Beta Band Power [Time frame: Immediately before vs. immediately after the ~30-minute session]
• Change in EEG Gamma Band Power [Time frame: Immediately before vs. immediately after the ~30-minute session]

Secondary outcome measures (1)

• Change in interoceptive accuracy score [Time frame: Immediately before vs. immediately after the ~30-minute session]

Eligibility criteria

Inclusion criteria

• Age 18-25 years
• Self-reported healthy status
• Literate in Turkish
• Willing and able to provide written informed consent

Exclusion criteria

• Active epilepsy or seizure history
• Diagnosed psychiatric disorder
• Neurological disorder
• Cardiac arrhythmia, pacemaker, heart disease
• Active use of psychotropic, beta-blocker, anticholinergic, or antihistamine medication
• Prior participation in Basic Body Awareness Therapy
• Pregnancy
• Active scalp lesion or dermatological pathology
• Neurological/psychiatric medication affecting alertness or attention
• Alcohol consumption in the last 24 hours
• Excessive caffeine intake on the day of measurement
• Acute pain, fever, infection, or other condition that could affect measurement

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Basic science

Study locations

Center list to be confirmed — check the primary protocol.

Publications

• Bravo C, Skjaerven LH, Espart A, Guitard Sein-Echaluce L, Catalan-Matamoros D. Basic Body Awareness Therapy in patients suffering from fibromyalgia: A randomized clinical trial. Physiother Theory Pract. 2019 Oct;35(10):919-929. doi: 10.1080/09593985.2018.1467520. Epub 2018 May 3. PMID 29723080
• Lundvik Gyllensten, A., Hansson, L., & Ekdahl, C. (2003). Outcome of Basic Body Awareness Therapy. A randomized controlled study of patients in psychiatric outpatient care. Advances in Physiotherapy, 5(4), 179-190. https://doi.org/10.1080/14038109310012061
• Schulz KF, Altman DG, Moher D; CONSORT Group. CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMJ. 2010 Mar 23;340:c332. doi: 10.1136/bmj.c332. PMID 20332509
• Schandry R. Heart beat perception and emotional experience. Psychophysiology. 1981 Jul;18(4):483-8. doi: 10.1111/j.1469-8986.1981.tb02486.x. No abstract available. PMID 7267933
• Petzschner FH, Weber LA, Wellstein KV, Paolini G, Do CT, Stephan KE. Focus of attention modulates the heartbeat evoked potential. Neuroimage. 2019 Feb 1;186:595-606. doi: 10.1016/j.neuroimage.2018.11.037. Epub 2018 Nov 22. PMID 30472370
• Mehling WE, Price C, Daubenmier JJ, Acree M, Bartmess E, Stewart A. The Multidimensional Assessment of Interoceptive Awareness (MAIA). PLoS One. 2012;7(11):e48230. doi: 10.1371/journal.pone.0048230. Epub 2012 Nov 1. PMID 23133619
• Lutz A, Slagter HA, Dunne JD, Davidson RJ. Attention regulation and monitoring in meditation. Trends Cogn Sci. 2008 Apr;12(4):163-9. doi: 10.1016/j.tics.2008.01.005. Epub 2008 Mar 10. PMID 18329323
• Lomas T, Ivtzan I, Fu CH. A systematic review of the neurophysiology of mindfulness on EEG oscillations. Neurosci Biobehav Rev. 2015 Oct;57:401-10. doi: 10.1016/j.neubiorev.2015.09.018. Epub 2015 Oct 9. PMID 26441373

Identifiers

NCT: NCT07736365 · Amasya Uni-BBAT

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗