Healthy
Conditions
Keywords
Healthy controls
Brief summary
Light is the primary means by which the internal circadian clock remains aligned (entrained) with the external world. Misalignment of this internal clock can occur during situations such as shift work and jet travel across multiple time zones (jet lag). The purpose of this study is to examine how sequences of brief flashes of light can affect entrainment of the clock.
Interventions
OTHERBright light
Light is administered through a custom designed mask with LED lights.
Sponsors
Stanford University
Palo Alto Veterans Institute for Research
VA Palo Alto Health Care System
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
The investigator is unaware of specific sequence of light that is given to the participant until all data are analyzed.
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Good health * Normal hearing
Exclusion criteria
* Sleep disorder * Extreme chronotype * Regular smoker * Depression * Alcohol abuse * Illegal drug use
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Circadian phase | 2 days | The timing of the onset of melatonin is compared before and after a light stimulus |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Alertness | 1 hour | Alertness as assessed through change in brain wave (electroencephalographic, EEG) activity, questionnaires, and objective testing is examined before and at the end of a light stimulus |
Countries
United States
Contacts
Primary ContactMarisol Duran
Outcome results
None listed