such as heroin, morphine and codeine including
methamphetamine. The methadone therapy must be
routinely done. Methadone is a group of opiate
analgesics that can be used to treat ongoing severe
pain (such as pain due to the cancer). This substance
works directly in the brain by changing how the body
feels and how the body responds to the pain.
Methadone is also used to treat dependence on
narcotic drugs (such as heroin) as an approved
therapy program. It can also help prevent withdrawal
symptoms due to the drug withdrawal (Hu, et al.,
2017; Wang, Kydd, Wouldes, Jensen, & Russell,
2015; Yang, et al., 2015; Malik, Adelson, Sason,
Schreiber, Peles, 2019). The success of substitution
therapy such as the methadone program for drug
addicts is higher than rehabilitation without drugs or
detoxification. Even with this therapy, the spread of
HIV can be suppressed because the use is done by
drinking. Some researchers have found that
methadone maintenance can significantly reduce
craving symptoms except in patients with heroin
dependence. Long-term consumption of heroin
causes adaptive changes in the brain system that may
last for a long time (Li, 2012). Verdejo, et al. (2005)
has found that methadone itself has the side effect of
causing cognitive impairment. Other researchers have
found that rehabilitation can effectively repair
impaired cognitive function caused by
buprenorphine, placebo, and methadone (Attou,
Figiel, Timsit-Berthier, 2001).
Electroencephalogram (EEG) is an activity that
records spontaneous brain activity in the form of
potential electrical signals along the scalp produced
by interconnected neurons. Among the medical use of
EEG, among others, for the diagnosis of diseases
associated with brain and psychiatric disorders
(Pastor, et al., 2019; Wang, Kydd, Wouldes, Jensen,
& Russell, 2015; Turnip, et al., 2018; Hu, et al.,
2017). EEG is also applied to detect a person's mind
patterns or mental condition. Visual observation of
the EEG signal directly is very difficult given the
amplitude of the EEG signal is so low and the pattern
is very complex. Besides that, EEG signals are
strongly influenced by various variables, including
mental condition, health, activity of the patient,
recording environment, electrical disturbances from
other organs, external stimulation, and age of the
patient. The nature of EEG signals in general is non
stationary and random so that adds complexity to the
processing of EEG signals (Turnip, et al., 2018; Hu,
et al., 2017; Iskandar, Kusumandari, Turnip, 2019;
Turnip, Kusumandari, Pamungkas, 2018). However,
the classification of EEG signals to changes in certain
variables can explain the work function of the brain
and capture changes in brain activity to the relevant
variable.
EEG signal in a person, generally consists of wave
components which are distinguished based on their
frequency region, namely: Human brain waves have
a range of frequencies and amplitudes - different so
that it is divided into several types of waves, namely:
delta waves (when deep asleep and without dreaming)
have the frequency is less than 4 Hz with an amplitude
of about 10 μV. Theta waves (occurring when light
sleep or drowsiness) have frequencies between 4 –8
Hz with an amplitude of around 10 μV; Alpha waves
(occur when relaxation or transition between
conscious and unconscious states) have a frequency
between 8-13 Hz with an amplitude of around 50 μV.
Beta waves (in a state of thinking or in the activity)
have a frequency between 13-19 Hz with an
amplitude between 10-20 µV. Gamma waves
(experiencing very high mental activity such as fear,
very panic, appearing in public) have a frequency
between 19-100 Hz (Motlagh, et al., 2018; Zhang, et
al., 2017). Therefore, the representation of EEG
signals into the frequency domain is mostly done in
research related to EEG signal analysis. In this study,
the use of EEG signals to observe the effect of
methadone administration on changes in brain
activity in the central, frontal, parietal, occipital, and
temporal parts is proposed. So far, methadone
experiments and observations of their effects on brain
activity using brain waves from EEG signals are still
rarely done.
2 METHODS
Experiments were carried out in a room that was
conditioned away from noise and provided comfort
for the subject (Figure 1). Before conducting an EEG
signal recording session, the subjects first directed
interviews with the medical team, filled out
information of concern, and follow the urine tests.
Then the subject is attached to an instrument in the
form of an electro-cap on the head and also tied a belt
to the chest of the subject so that the electro-cap does
not shift. Subjects were briefed regarding the
experimental scenario. The EEG signals are recorded
through 19 channel electrodes, including Fp1, Fp2,
F7, F3, Fz, F4, F8, T3, C3, Cz, C4, T4, T5, P3, Pz,
P4, T6, O1, and O2. The reference in this experiment
uses electrodes mounted on the ear, the A1 and A2
channel electrodes, which are A1 for the left ear and
A2 for the right ear. When installing electrodes, a gel
is applied to each EEG sensor to increase
conductivity while maintaining impedance between