By Pär Westlund

Taking a beginner’s course in Acem Meditation involves not only learning the basic instruction in the technique. Participants also receive advice on what conditions are favorable for developing a good meditation practice, both in regular life and at meditation retreats.

When we meditate, the basic principle is that we open our awareness towards what spontaneously emerges in our mind, thus creating freedom for the spontaneous activity that is there to express itself. We repeat the meditation sound as gently as we can, independently of what goes on in our minds – without expecting that the spontaneous activity should be of a certain kind, or that it should change or go away. The content and nature of the spontaneous activity may shift of its own accord during meditation – not because we deliberately try to lead it in a specific direction with our will, but as a result of our adopting a free mental attitude when we repeat our meditation sound.

The gentle and effortless repetition of the meditation sound in the mind triggers several physiological responses. We may enhance the beneficial impact these responses have in our meditation by creating favorable conditions that help us to obtain the best effects.

Closing our eyes

When practicing nondirective meditation methods such as Acem Meditation, two types of changes occur in brain activity which can be measured by an electroencephalogram (EEG). When the meditator adopts an inner-directed awareness towards the spontaneous activities of the mind, i.e. follows the basic principle of the free mental attitude:

  • Theta waves increase, which is a sign of increased inner-directed awareness.
  • Alpha waves increase, which is a sign of increased restful awareness.

The recommendation is to meditate with your eyes closed and with the light dimmed or as dark as possible. If we meditate with our eyes open or strongly focus our attention, which is often goal-directed and allows less freedom for the spontaneous activity to express itself, we will not obtain the same kind of change in our brain waves. Approximately 30 % of the brain’s activity is used to receive and process impressions while we are awake with our eyes open. Meditation with our eyes open leads to massive activation of the brain. During meditation, the activation takes part inside the brain, in contrast to the normal function of eyesight, from the outside-inwards. During meditation, images, thoughts, etc. that are not necessarily associated with immediate external stimuli emerge.

External sounds

External sounds may impede our meditation. If we meditate in surroundings with a lot of sounds, our attention may easily be captured by them. This may contribute to the «drowning out» of parts of the spontaneous activity. We may get irritated and disturbed by the sounds and try to close off the noise, as well as the thoughts they activate in our minds. We may then become too active in trying to avoid certain thoughts and impressions with the meditation sound and lose the free mental attitude. We restrict the freedom of the spontaneous activity which should have been present, were it not for the external stimuli. The same goes for other sense qualities – where some demand more attention than others.

Bodily processes

Bodily processes impact our meditation. After a large meal, more of our energy and attention is involved in the automatic activation of the body that takes place during digestion, which makes us more drowsy.

Coffee has an impact on us. Many find coffee stimulating. In everyday life, coffee-drinkers may not notice the effects of caffeine so much in their meditation. However, before retreats, participants are recommended to quit drinking coffee, as well as black and green tea, which contain a similar stimulant, the week before. This reduces the effect of caffeine on long meditations and helps to avoid headaches due to caffeine abstinence. According to the basic principle in Acem Meditation, we try to minimize the impact of external stimuli in order to encourage a process that should be allowed to have its own dynamic.

Physical exercise or jogging just before the meditation often increases the need to recover before the meditation time. It is important that we have time to recover before the meditation and that we do not have too much lactate in the body when we meditate. On the other hand, walking at an easy pace, and yoga, are good ways to prepare for meditation. They may make it easier to handle the bodily restlessness we may encounter during meditation.

The relaxation response

The recommendation is to sit in a position that provides good support for the lower back and with your feet resting on the floor, alternatively with your legs stretched out in the bed. Your posture should involve as little activation of your muscles as possible.

Meditation triggers a relaxation response as a result of a reduction in the activity of the sympathetic part of the autonomous nervous system. This part of the nervous system is activated in different ways when we need to achieve something, or when we have to protect ourselves against a possible threat, often known as in the fight or flight response. During meditation, the activity in the sympathetic nervous system is reduced – which is the opposite of what occurs during stress.

The other part of the autonomous nervous system is the parasympathetic system, which stimulates rest and recovery. The combination of changes in signals both in the sympathetic (reduced) and parasympathetic (increased) systems that occur during meditation makes us relax. A scientific study of Acem Meditation examined the signals in the nervous system that go from the brain to the heart. The activity in separate nerves was measured (2). The study showed that a reduction of signals starts immediately in the sympathetic nervous system,  while the increase in the activity of the parasympathetic nervous system takes place more slowly. When we repeat the meditation sound effortlessly and without being goal-directed, an important change in the functioning of the autonomous nervous system takes place. Relaxation occurs without our deliberately deciding to relax. This is called «the relaxation response» and was discovered by the Harvard researcher Herbert Benson in the 1970s (3).


It is relatively common to fall asleep during meditation. Such sleep is part of the spontaneous activity of the mind, and it is important to allow it to come during meditation. We should therefore not try to avoid sleep in our meditation. Even to sleep is to meditate in the right way. Sleep during meditation may be due to a lack of sleep, or may be a result of an actualization, and is worked through when we allow it to come.

The importance of accepting sleep is particularly clear in the first part of a retreat. It is common to sleep more in this phase, sometimes in several consecutive meditations. Allowing sleep to come opens us, and deeper parts of our psychology become more accessible to us. If you get very sleepy during the meditation in a retreat, it is good to lie down and allow the sleep to come. If you do not fall asleep when you lie down, you simply sit up and continue with your meditation. Struggling against succumbing to sleep means that we are not dealing with the sleep with a free mental attitude.

The meditation sound

The kind of meditation sound we use in meditation, and how we use it, is also important. The meditation sounds that are used in Acem Meditation have no semantic meaning but have a harmonizing effect on us through their rhythm and the combination of syllables that relaxes us in repetition. In addition, the meditation sound also has a provocative effect, which induces those parts of us that we experience as limitations to express themselves in meditation.

Functional magnetic resonance imaging  – fMRI – is a way of measuring changes in the blood circulation in different parts of the brain, while simultaneously providing a detailed image of the brain’s anatomy.  In this way, fMRI measures the activity of various parts of the brain. fMRI was used to gain a better understanding of how different meditation sounds affect the brain during meditation. One study indicated that the repetition of meditation sounds with a semantic meaning does not activate the brain in the same way as meditation sounds without such meaning (4). Another study indicated that different parts of the brain are activated if we repeat the meditation sound effortlessly or with concentration, (5). Both the meditation sound and the way we repeat it has an important effect on the brain, and therefore on the results of the meditation.

The greatest change which is revealed in fMRI that takes place in the brain during meditation occurs in the prefrontal cortex. The prefrontal cortex – just above the left eye – is the part of the brain that grows most during our development, and is important for the processing of impressions that takes place both when we are awake and when we sleep.

In the meditation – through an effortless repetition of the meditation sound – we try to provide favorable conditions that stimulate the brain’s spontaneous activity. In our everyday life, daily residues are often actualized in the meditation – including what has happened during the day, as well as thoughts about what will happen in the near future. In addition, memories and events from the more distant past may emerge.

In long meditations, experiences and memories from the near or more distant past often become more prevalent. Irrespective of what comes up, it is important that we try to deal with the contents of our spontaneous activity in our meditation with as much of a free mental attitude as possible in our repetition of the meditation sound.


1) J Lagopoulus et al. (2009) Increased theta and alpha EEG activity during nondirective meditation. Journal of Alternative and Complementary Medicine, pp. 1187-1192.

2) A Nesvold et al. (2011). Increased heart rate variability during nondirective meditation. European Journal of  Preventive Cardiology, pp. 773-80.

3) H Benson and M Z Klipper. The Relaxation Response, Harper Collins, 2000.

4) M Engstrom et al. (2010), Journal of Alternative and Complementary Medicine.16, pp. 1253-1258.

5) J Xu et al. (2014). Nondirective meditation activates default mode network and areas associated with memory retrieval and emotional processing. Frontiers in Human Neuroscience 8, pp.1-10..