The main goal of this study is to answer the following questions: What is the relative contribution of the photoreceptors for the NIF effects of pupil constriction and alertness? What are the frequencies of light which minimise the adaptation of the…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
Daytime pupil response and alertness
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Pupillary unrest index, pupil response (constriction and adaptation during
exposure to light)
Secondary outcome
n.a.
Background summary
When we are looking at the pupilresponse during long-duration light exposure,
the usual response consists of a transient contraction followed by a relaxation
towards the dark-adapted state of the pupil. Although it has long been thought
that this relaxation is finished after a few minutes of time, recent research
suggests that this relaxation takes place for at least half an hour after
lights-on (Gooley et al., 2013). This slow relaxation can be countered by
exposing the eye to flickering light, and the researchers think that this is
because the cones have the opportunity to increase their sensitivity during
lights-off, which increases the contribution of the cones. We want to test how
different photoreceptors (s,m and l-cones, but also melanopsin ganglion cells)
are involved in this effect. To test this, we will make use of the spectral
composition protocol, in which the spectrum of the light source is dynamically
altered in such a way that only 1 photoroceptor "sees" the difference. Also, we
want to know at what frequencie aforementioned effect will be largest (as
little as possible relaxation towards dark-adapted state), which is why we want
to test multiple frequencies. With this protocol, we will isolate 3 cone
classes and the melanopsin ganglion cells. This means that each person needs to
come to the lab multiple times, to test each frequencies for a randomly
assigned photoreceptor modulation. Besides adaptation in the pupil response, we
are also interested in alertness during office hours, which we will assess by
means of the pupillary unrest index, which is a proxy for alertness.
Study objective
The main goal of this study is to answer the following questions: What is the
relative contribution of the photoreceptors for the NIF effects of pupil
constriction and alertness? What are the frequencies of light which minimise
the adaptation of the pupil and maximise alertness for each photoreceptor
(melanopsin, S-cone, M-cone and L-cone)?
Study design
This experiment follow a between/within-subject experimental design. The
between-factor will be the isolated photoreceptor. The within-factor will be
the frequency of the oscillation. The intervention consists of exposure to
different (dynamic) lighting protocols.
Intervention
Licht met een fluctuatie in intensiteit met een frequentie van 0, 0.5, 1, 2, 4
en 8 Hz.
Study burden and risks
There are no risks associated with this study. The device is used according to
its intended use and has been extensively tested for safety.
The total burden for participants consists of 6 visits to the lab (65 minutes
per visit, 390 minutes in total), to comply with set sleep/wake times which
will be checked with daqtometer data, and to fill in a number of forms before
the actual experiment (~30 minutes)
Nijenborgh 7
Groningen 9747 AG
NL
Nijenborgh 7
Groningen 9747 AG
NL
Listed location countries
Age
Inclusion criteria
healthy men and women (18-30 y)
normal chronotype
normal sleep duration
women using a hormonal form of birth control (steady hormone levels)
Exclusion criteria
short (<6.5h) or long sleeper (>9h)
going out more than two nights a week until minimally 7AM
extreme early or late chronotype
chronic (psychiatric or somatic) disease
sleep disorder
eye complaints or eye surgery in the past (excluding use of contact lenses)
use of chronic (photosensitizing) medication in 3 months prior to start of stydt
regulary use of sleep medication or stimulating drugs
colour blindness
more than 3 glasses of alcohol on working days, and or the regularly use of drugs
more than 8 caffeinated drinks per day
regularly napping (more than 2 times a week)
shiftwork in 3 months prior to the start of the study
travelled across more than 1 timezone in the month prior to the start of the study
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL53779.042.15 |