Atanasov AT. Stabilizing Effect of Yawning
on Nasal Cycle. Global Neuro
2020;1(2):107-109.
Atanas Todorov Atanasov
The dominant passability of the left or right
nostril in terms of nasal air resistance can be
classified into 4 main modes. In the first mode,
both nostrils are closed and have equal and low
air passability. In the second mode, the
passability of the right nostril is higher than
the left. In the third mode, the passability of
the left nostril is higher than the right. In
the fourth mode, both nostrils are open and
passability of nostrils is equal and high. The
first and fourth modes are unstable (with
duration- minutes). The second and third modes
are stable (with duration-hours). Author
presents a yawning as physiological reflex
leading to transition from unstable to stable
modes.
Introduction
Yawning consists of an involuntary wide
opening of the mouth and long and deep air
inhalation through the mouth, followed by a slow
expiration with duration from 3 to 45 s
[1]. Yawning may be associated with
tears, shivering, obstruction of the Eustachian
canal, stretching of the limb, monotonous work
and others. One commonly held notion is that
yawning functions to modify levels of oxygen and
carbon dioxide in blood [2]. A more
recent hypothesis proposed that yawning
facilitates arousal [3]. Indeed, the
yawning always announces a stage between
awakeness and sleep. Regardless of the proposed
hypotheses, up to now, there is no research in
the scientific literature on the effect of
yawning on the nasal cycle. Scientific theory
consistently states that there are important
connections between the nasal passages and the
psyche. During spontaneous breathing, inhaling
through the left nostril is said by most people
to have a calming, beneficial, stabilizing
effect, where breathing through the right
nostril is destabilizing, excitatory and
ultimately enervating [4]. A balance
between the two modes is thought to be most
suitable for the challenges of daily life, and
is put forth as a teleological explanation for
the ultradian rhythm of congestion/decongestion
that occurs in the nose throughout the day. This
cycle of naturally occurring congestion in one
nostril with relative decongestion in the other
nostril, followed by the reverse, occurs every
1.0-5.0 hours [5]. Central nervous
system and hemisphere brain EEG activity
correlates of nostril laterality documented by
[6]. The nasal cycle during night sleep
multiple to time-period of about 1.5h and
synchronized with sleep cycle. The
synchronization of the nasal and sleep cycle
leads to switch of nostril air passage (from
left to right dominating passages and reverse)
during the REM phases of sleep, firstly
documented by Atanasov et al. [7,8]. In
this connection, the first daily nasal cycle
starts during the last REM sleep cycle. After
waking up and passing from passive (relaxed)
state to active (concentrated) state of the
mind, the necessity of higher brain, body and
psych activity arise. This can be achieved by
series of yawning which lead to higher metabolic
activity of brain and body [1]. Data of
Atanasov [9] show that the nostrils
cavity have four mode of work, regard to
domination of left or right nostril air
passability (Figure 1). In the first mode, the
two nostrils are closed (with equals and lower
air passability). This mode is observed during
strong fatigue, insufficient sleep or headache.
The second mode of the nasal cycle (with low air
flow trough left nostril and high trough right
nostril) it is observed during relaxation,
warming the body, boredom, drowsiness and lower
concentration capacity. The third mode of the
nasal cycle (with high air flow trough left
nostril and low trough right nostril) it is
observed during concentration, cooling of the
body and transition from passive to active state
of brain, psych or skeletal muscles. In the
forth mode of the nasal cycle the two nostrils
are open (with equal and high air passability).
This mode is observed during hyperactivity of
brain, psych and intense physical or mental
pressure. The first and fourth modes are
unstable (have a duration of less than 10-30
minutes). The second and third modes are stable
(have a duration about 1-5 hours). The effect of
yawning on the nasal cycle and nostril's air
permeability has not been studied in the
scientific literature. The physiological meaning
of yawning is still unclear [10]. Thus,
the aim is to study the effect of yawning on the
nasal cycle.
Working hypothesis
The first and fourth modes are unstable (have
a duration of less than 30 minutes). The second
and third modes are stable (have a duration
about 1-5 hours). Author presents a yawning as
physiological reflex leading to transition from
unstable first and forth modes to stable second
and third modes. During daily work it is
required higher attention and higher metabolic
activity. This is achieved by series of yawning,
one after another, leading to transition from
mode 1, 2 and 4 to mode 3. During mind and
physical relaxation, the yawning lead to
transition from mode 1, 3 and 4 to mode 2.
Result and Discussion
Upon all of the participants, regarding of
their age, the yawning lead to one and same
stereotypic reactions. Firstly, the yawning
occurs when the left and right nostrils have
nearly equal air passability. On Figure 2 is
illustrated that all modes with equal
passability (Figure 2, picture 1) generate
yawning that lead to modes with different air
passability (Figure 2, picture 2). In all cases,
after yawning, the air passability of the right
nostril decreases, while the air passability of
the left nostril increases. This leads to
domination of mode 3. Secondly, the yawning has
stabilizing effect on mode 3 during active mind
and physical activity, and has stabilizing
effect on mode 2, during transition to lower
physical and psych activity. The duration of
transition from unstable modes with equal air
passability to stabilized modes with different
air passability (after series of 3-4 yawning)
varies between 12-20 minutes and more. On Figure
3 is demonstrated the stabilizing effect of
yawning on 2 and 3 modes. From this figure can
observed that on the one hand, the yawning leads
to transition from mode 1 and 4 to mode 2 and 3,
and on the other hand leads to inter-transition
between mode 2 and mode 3. Third, during daily
time in 60-70% of all cases the final effect of
yawning leads to stabilization of mode 3. For
example, on Figure 4 is shown record of the air
flow passages through nostrils of healthy man
(50 years). The airflow of the left nostril is
increased after each following yawning. Mode 3
is established and stabilized after series of
tree yawning. The experiment shows - after this,
yawing stops. The stabilizing effect of mode 3
on psyche do not study in scientific literature,
but possibly this effect has a connection with
contra-laterally function on brain hemisphere.
Commonly, the establishing of mode 3 occur after
series yawning and alternative nostrils
switching from modes 1, 2 and 4 to mode 3 and
reverse for time-periods of about 3 up to 15- 20
min and over. This alternative nostril switching
is very similar to alternative breathing trough
left and right nostrils in yoga- practice for
period to 20-30min, leading to clearing and
stabilizing of the mind. During a yawning, a
massive inspiration of oxygen and exhalation of
CO2 serve to reverse blood hypoxia and to
increase the metabolic rate. This reverse
drowsiness, maintaining the brain at the level
of alertness needed for wakeful activities
[9]. Possibly the metabolic level of the
brain and body is connected with domination of
nostril's air passage. Thus, the study confirms
the hypothesis that, the nasal cycle possibly is
associated to different states of consciousness
[11,12]. In future, an additional
technique and methods are need to strengthen the
proposed hypothesis.
