Condition category
Not Applicable
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
There is considerable debate among scientists over why we yawn, and the mechanism of yawning is still not fully understood. About half of adults yawn after someone else yawns due to a phenomenon called contagious yawning. The aim of this study is to test whether levels of the hormone cortisol are higher during yawning and contagious yawning, just as cortisol levels are raised during stress and fatigue.

Who can participate?
Volunteers aged 18-65 will be recruited from students at Bournemouth University.

What does the study involve?
Participants are exposed to three conditions intended to provoke yawning – photos of people yawning, boring text about yawning, and a short video of a person yawning. We collect saliva samples from participants at the start and after yawning to measure saliva cortisol levels, and record the electrical activity of their jaw muscles via surface-placed electrodes. Questionnaires about yawning, anxiety and depression, general health, and demographic and health details are also collected from each participant.

What are the possible benefits and risks of participating?
The results of this study may improve our understanding of yawning and its role in many neurological disorders, and allow us to develop a diagnostic tool for neurological disorders. There are no risks involved. All participants will have the right to withdraw at any time and will be debriefed. All data is anonymised.

Where is the study run from?
Bournemouth University (UK).

When is the study starting and how long is it expected to run for?
June 2012 to December 2012.

Who is funding the study?
Bournemouth University and Santander plc (UK).

Who is the main contact?
Dr Simon Thompson

Trial website

Contact information



Primary contact

Dr Simon Thompson


Contact details

Bournemouth University
Talbot Campus
Poole House (P315)
Fern Barrow
BH12 5BB
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Thompson Cortisol Hypothesis: trial to investigate the maintenance effects of Yawning on salivary Cortisol levels - an observational study



Study hypothesis

Cortisol levels rise during the yawning episode

Ethics approval

Bournemouth University Research & Ethics Committee, 05/10/2011, ref: BU-PS5/10/11-PS1/3/12
Amendments approved 01/03/2012

Study design

Observational study

Primary study design


Secondary study design

Cross sectional study

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Salivary cortisol levels


Collection of saliva samples; collection of non-invasive surface-placed electrode data of electrical nerve impulses around jaw-line during yawning.

Observing participants' yawning, their level of saliva cortisol before and after yawning, and their electrical (nerve) activity around the jaw muscles at rest and during yawning. The duration of observation is determined by the time it takes to view the stimuli (about 20 minutes) and to yawn. If yawning occurs before all the stimuli have been viewed, then the observation period is shorter for the participant as the stimuli merely serve to elicit a yawn. We aim to conduct a longitudinal study at a later date once data has been analysed and results are known.

Intervention type



Not Applicable

Drug names

Primary outcome measures

1. Salivary cortisol levels - collection of saliva deposited (spit into tube) by each participant into sample bottle at start of study then again immediately after yawning, or if no yawn elicited, at end of last stimuli presentation
2. Electrical nerve activity - non-invasive surface-placed electrodes around the jaw line receive data throughout the study (20 mins maximum), or only until yawning is elicited, whichever happens first

Secondary outcome measures

Demographic and descriptive details of participants age, gender, ethnicity

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. 100 male and female volunteers aged between 18-65 years will be recruited from students at Bournemouth University using the computerised recruitment system (SONA), and Facebook
2. All participants will be properly consented according to code of conduct and research guidelines

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Chronic fatigue
2. Diabetes
3. Fibromyalgia
4. Heart condition
5. High blood pressure
6. Hormone replacement therapy
7. Multiple sclerosis
8. Stroke

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Bournemouth University
BH12 5BB
United Kingdom

Sponsor information


Bournemouth University (UK)

Sponsor details

c/o Dr Simon Thompson
Associate Professor
Talbot Campus
Poole House (P315)
Fern Barrow
TS17 6QQ
United Kingdom

Sponsor type




Funder type


Funder name

Bournemouth University (UK) ref: BU-26.08.11

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype



United Kingdom

Funder name

Santander plc (UK) ref: SANTANDER-30.09

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

2012 results in:

Publication citations

Additional files

Editorial Notes