**3. Effect of unilateral nostril breathing in various physiological and psychological changes**

It is well understood that there exists a strong relation between nasal cycle with physiological and behavioral changes. There is a slight, but significant correlation between the dominant nostril and the relative cognitive performance in free breathing subjects is observed [9]. The vasomotor and secretory activity of the nasal mucosa in healthy volunteers are observed and reported that the nasal secretions over the mucous membrane had a definite relation to the congestion of the turbinal structures [17]. The modification in actual nasal cycle rhythms in terms of change in period length, increase or decrease in strength of the rhythm, or desynchronization, and uncoupling of rhythms are observed in depressed patients [18].

the left hemisphere, the right nostril dominance is found. During the left nostril dominance,

Alteration in Nasal Cycle Rhythm as an Index of the Diseased Condition

http://dx.doi.org/10.5772/intechopen.70599

27

It is noticed that the nostril cycle also has an influence on neurotransmitters and hormones. For example, FUNB has an effect on involuntary blink rates, which are directly related to dopaminergic activity. Blink rates have been significantly increased during left FUNB, which indicates the association between right hemispheric preference and a possible lateralization of dopamine. Studies have also shown that there is a strong relationship between dominant nostril airflow with plasma catecholamines, such as norepinephrine, epinephrine, and dopamine. The ratio of plasma catecholamines from samples taken in each arm correlates with

Furthermore, the effects of nostril cycle are also apparent in the endocrine system. The levels of pituitary hormones (adrenocorticoids, luteinizing hormones) as well as catecholamines varied according to the nasal cycle [30]. The alteration in nasal cycle correlated with autonomic nervous system results with indicating alternating lateralization of catecholamines in

The nasal cycle also supports three general conclusions with respect to brain activity are: (1) nasal cycle dominance correlates with changes in hemispheric EEG differences; (2) in free breathing subjects, relative performance on spatial and verbal tasks is related to nostril dominance; and (3) at least theoretically, unilateral forced nostril breathing (UFBN) may differentially affect the ipsilateral and contralateral cerebral hemispheres, thereby changing

In addition to the effects of the nostril cycle in psychological effects, research has also explored in many physiological effects, with an emphasis in autonomic activity, especially in human heart. It is evident that heart rate and mean arterial pressure in dogs varies in a cycle that lasts approximately 1.5 hours [32, 33]. From this, researchers have concluded that the internal variations of the heart drive by the sympathetic nervous system [30]. FUNB studies have shown that the nostril cycle affects intraocular blood pressure: right nostril breathing reduces it and left nostril breathing increases. Similarly, nostril dominance has been shown to affect blood glucose level: right FUNB increased blood glucose levels, while left FUNB decreased the levels. Homeostasis of glucose levels is regulated by the autonomic nervous system [20]. During the night sleep, there is synchronization of nasal and sleep cycles in some of the REM phases of sleep, the length of periods of the nasal cycle is one or more length of sleep cycle [34]. From the above literatures, it is clear evident that analyzing the characteristic of nasal cycle becomes most important since there is a strong association between the physiological

relative EEG activity and influencing relative spatial and verbal performance [31].

**4. Analyzing characteristic of nasal airflow in healthy subjects**

From the experiments conducted by recording nasal air flow from two nostrils, there exists predominant airflow in only one nostril that justifies the existence of nasal cycle. Twenty

and psychological changes in human with nasal cycle.

they perform better in spatial tasks, associated with the right hemisphere [23].

nostril dominance [12].

one of the two arms [12].

Nasal resistive reflexes, which are anatomically mediated may change the nasal resistance [19]. Studies on nasal cycle prove its importance on clinical aspect that breathing through the right nostril increases blood glucose level significantly whereas through left nostrils decreases [20]. Also, breathing through right nostril increases metabolism whereas breathing through the left nostril decreases sympathetic activity to the sweat glands [21].

Alternative nasal airflow activates alternative hemispheres of the brain, right dominant airflow activates left hemisphere of brain and vice versa, since the right hemisphere of brain is responsible for creative thinking whereas the left hemisphere of brain is responsible for logical thinking. During EEG measurements, rapid eye movement (REM) and non-rapid eye movement (NREM) was noticed and correlated with left and right hemisphere brain activity [22]. It is suggested one can selectively activate a hemisphere depending on which functions are mostly needed at a certain point in time [4, 23].

Nasal cycle has a strong correlation with psychological changes in wake state as well as in sleeping state both for normal and abnormal subjects [24, 25]. Even though many researchers found the origin of the system responsible for this nasal rhythm oscillation [26], the factor which controls this rhythm is still ambiguity [27]. In nineteenth century, German scientist Kayser sparked interest in the nostril cycle [4] studied the nostril cycle and the effects of forced unilateral nostril breathing (FUNB). In this experiment, subjects are instructed to block one nostril and breathe through the other nostril for a period of 1–30 minutes; during the period both physiological and psychological parameters are measured.

The participants' nostrils are categorized to the independent decongested nostril, that is, the nostril with dominant airflow. Nostril dominance is measured by the collection of quantitative data during FUNB to measure nostril dominance, and the corresponding effects on the brain and the heart was recorded. Long-term studies of the nostril cycle have been very limited. One month study was conducted by Funk and Clarke [28], but observed only weak patterns in nostril dominance and failed to identify possible factors responsible for the variability.

To explore the possible effects of the nasal cycle on the brain, it is important to understand the alterations in cognitive processes that are responsible for each cerebral hemisphere. Generally, it is well known that the left hemisphere is responsible for language processing whereas the right hemisphere is for visual processing. Certain research indicates the individual differences in the degree to which one cerebral hemisphere rather than the other in processing the various information [29]. This is referred to as hemispheric dominance.

The qualities assigned to each nostril are assumed to correspond with brain hemispheric dominance. Physiologically, electro-cortical activity in one hemisphere (measured by greater EEG power) relates to contra lateral nostril dominance [7]. This relationship has been intensively analyzed by forced unilateral nostril breathing (FUNB). For example, participants perform better in cognitive tasks that require rational and logical thinking, where tasks associated with the left hemisphere, the right nostril dominance is found. During the left nostril dominance, they perform better in spatial tasks, associated with the right hemisphere [23].

reported that the nasal secretions over the mucous membrane had a definite relation to the congestion of the turbinal structures [17]. The modification in actual nasal cycle rhythms in terms of change in period length, increase or decrease in strength of the rhythm, or desyn-

Nasal resistive reflexes, which are anatomically mediated may change the nasal resistance [19]. Studies on nasal cycle prove its importance on clinical aspect that breathing through the right nostril increases blood glucose level significantly whereas through left nostrils decreases [20]. Also, breathing through right nostril increases metabolism whereas breathing through

Alternative nasal airflow activates alternative hemispheres of the brain, right dominant airflow activates left hemisphere of brain and vice versa, since the right hemisphere of brain is responsible for creative thinking whereas the left hemisphere of brain is responsible for logical thinking. During EEG measurements, rapid eye movement (REM) and non-rapid eye movement (NREM) was noticed and correlated with left and right hemisphere brain activity [22]. It is suggested one can selectively activate a hemisphere depending on which functions

Nasal cycle has a strong correlation with psychological changes in wake state as well as in sleeping state both for normal and abnormal subjects [24, 25]. Even though many researchers found the origin of the system responsible for this nasal rhythm oscillation [26], the factor which controls this rhythm is still ambiguity [27]. In nineteenth century, German scientist Kayser sparked interest in the nostril cycle [4] studied the nostril cycle and the effects of forced unilateral nostril breathing (FUNB). In this experiment, subjects are instructed to block one nostril and breathe through the other nostril for a period of 1–30 minutes; during the

The participants' nostrils are categorized to the independent decongested nostril, that is, the nostril with dominant airflow. Nostril dominance is measured by the collection of quantitative data during FUNB to measure nostril dominance, and the corresponding effects on the brain and the heart was recorded. Long-term studies of the nostril cycle have been very limited. One month study was conducted by Funk and Clarke [28], but observed only weak patterns in nostril dominance and failed to identify possible factors responsible for the variability.

To explore the possible effects of the nasal cycle on the brain, it is important to understand the alterations in cognitive processes that are responsible for each cerebral hemisphere. Generally, it is well known that the left hemisphere is responsible for language processing whereas the right hemisphere is for visual processing. Certain research indicates the individual differences in the degree to which one cerebral hemisphere rather than the other in processing the

The qualities assigned to each nostril are assumed to correspond with brain hemispheric dominance. Physiologically, electro-cortical activity in one hemisphere (measured by greater EEG power) relates to contra lateral nostril dominance [7]. This relationship has been intensively analyzed by forced unilateral nostril breathing (FUNB). For example, participants perform better in cognitive tasks that require rational and logical thinking, where tasks associated with

chronization, and uncoupling of rhythms are observed in depressed patients [18].

the left nostril decreases sympathetic activity to the sweat glands [21].

period both physiological and psychological parameters are measured.

various information [29]. This is referred to as hemispheric dominance.

are mostly needed at a certain point in time [4, 23].

26 Pathophysiology - Altered Physiological States

It is noticed that the nostril cycle also has an influence on neurotransmitters and hormones. For example, FUNB has an effect on involuntary blink rates, which are directly related to dopaminergic activity. Blink rates have been significantly increased during left FUNB, which indicates the association between right hemispheric preference and a possible lateralization of dopamine. Studies have also shown that there is a strong relationship between dominant nostril airflow with plasma catecholamines, such as norepinephrine, epinephrine, and dopamine. The ratio of plasma catecholamines from samples taken in each arm correlates with nostril dominance [12].

Furthermore, the effects of nostril cycle are also apparent in the endocrine system. The levels of pituitary hormones (adrenocorticoids, luteinizing hormones) as well as catecholamines varied according to the nasal cycle [30]. The alteration in nasal cycle correlated with autonomic nervous system results with indicating alternating lateralization of catecholamines in one of the two arms [12].

The nasal cycle also supports three general conclusions with respect to brain activity are: (1) nasal cycle dominance correlates with changes in hemispheric EEG differences; (2) in free breathing subjects, relative performance on spatial and verbal tasks is related to nostril dominance; and (3) at least theoretically, unilateral forced nostril breathing (UFBN) may differentially affect the ipsilateral and contralateral cerebral hemispheres, thereby changing relative EEG activity and influencing relative spatial and verbal performance [31].

In addition to the effects of the nostril cycle in psychological effects, research has also explored in many physiological effects, with an emphasis in autonomic activity, especially in human heart. It is evident that heart rate and mean arterial pressure in dogs varies in a cycle that lasts approximately 1.5 hours [32, 33]. From this, researchers have concluded that the internal variations of the heart drive by the sympathetic nervous system [30]. FUNB studies have shown that the nostril cycle affects intraocular blood pressure: right nostril breathing reduces it and left nostril breathing increases. Similarly, nostril dominance has been shown to affect blood glucose level: right FUNB increased blood glucose levels, while left FUNB decreased the levels. Homeostasis of glucose levels is regulated by the autonomic nervous system [20].

During the night sleep, there is synchronization of nasal and sleep cycles in some of the REM phases of sleep, the length of periods of the nasal cycle is one or more length of sleep cycle [34]. From the above literatures, it is clear evident that analyzing the characteristic of nasal cycle becomes most important since there is a strong association between the physiological and psychological changes in human with nasal cycle.
