Regulating centers of vital functions are placed in
the nuclei of the brain stem, midbrain, pons and the
cerebellum, as well as - in the autonomic nuclei of the
brain and spinal cord. Many of the mentioned
pathways are located in the neck.
The nervous formations of neck area are closely
associated with brainstem, which have two-side
connections with midbrain, cerebellum, thalamus,
hypothalamus and the large brain cortex. Presence of
these connections provides participation of the neck
nervous formations in analysis of sensory
stimulation, regulation of the muscle tonus,
autonomic and the highest integrative functions
(Moore et al., 2013, Netter, 2014).
As a stimulation targets can be used not only the
superior cervical ganglia of the sympathetic nervous
system and (or) the stellate ganglion, but also other
components of the sympathetic trunk, the afferent
branches of the cervical plexus, cranial nerves and
their branches (IX, X and XI pair) that are conductive
paths nerve structures of the brainstem. And it
significantly extends the capabilities of the
neurostimulation method (Kublanov et al., 2015).
The stimulation of neck nodes of the sympathetic
trunk affects both the vascular tone of arteries of the
brain, and autonomic spinal nucleus (Klosovskiy,
1951). Thus, our hypothesis is that neuro-
electrostimulation system is able to fully modulate the
autonomic processes and to affect motor control and
cognitive function.
Features of the neuro-electrostimulation realized
using the «SYMPATHOCOR-01» device:
the target of neuro-electrostimulation can be
changed in accordance with current task by
selecting of partial electrodes as anodes of the
multi-element electrode which involved in
formation of the current pulse field;
biotropic parameters of field of current pulse
(amplitude, frequency and duration) are selected
in accordance with the state of autonomic balance:
activity of the sympathetic nervous system is
blocked at sympathicotonia, and is activated at
vagotonia;
the frequency of switching the partial electrodes
of the multi-electrode performing the role of
anodes is at least by N times smaller than the
switching frequency of the partial electrodes
performing the role of cathodes;
commutation (switching) of these electrodes is
performed either clockwise, or counter-
clockwise, or in the arbitrary order by a random
law (Kublanov, Petrenko and Babich, 2015).
Parameters of the current pulsed field were as
follows: the amplitude of the partial current pulses is
4mA, the pulse duration of the partial current is 50
microseconds, the frequency of the partial current
pulses is 80 Hz.
2.2 Method for the Estimation of
Attention Parameters
The study was approved by the local ethics committee
at the Ural State Medical University in accordance
with the protocol number 8 on October 16, 2015.
The study involved 15 participants aged 18 to 35
years who gave their informed consent to voluntary
participate in the study.
The study consisted of 4 stages. The sequence
diagram of the experiment is shown in Table 1.
Table 1: Sequence diagram.
№ stage Name of stage Duration, min.
1 Base line 5
2 Stress testing (Bourdon- test) 10
3
Neuro-electrostimulation
procedure
20
4
Repeated stress testing
(Bourdon test)
10
Methodology «Bourdon test» was used for the
estimation of attention parameters (Brunner, 2006).
Table filled with symbols formed randomly was
presented to participants at Bourdon test
performance. Looking through the table row by row,
the participants must locate and highlight certain
characters. Bourdon test is designed to assess the
stability of the volume and switching of attention. The
quality of the test was assessed by the speed of
browsing, the general number of errors, the number
of omission errors, the number of commission errors,
the number of scanned characters and productivity
index. Prior to the study subjects were conducted a
training session to familiarize themselves with the
Bourdon test. Training session and research carried
out on different days.
The adapted subjective questionnaire of acute
mental fatigue by A.B. Leonova was used to assess
the mental fatigue (Leonova and Velichkovskaia,
2002). The questionnaire contains 18 statements
describing different degrees of mental fatigue. Index
of mental fatigue (IMF) was calculated based on these
data. Mental fatigue is the most important factor that
limits human performance in the workplace,
especially in learning activities (Karpenko, 2008).
IMF estimation was carried out after each stage of the
study.