Vicente M. Simón Ph.D. M.D.

 

Abstract

Recently, in specific research and publications, we observe the introduction of the term mindfulness and its techniques in the fields of education, psychotherapy and science in general. One of the reasons for this development is the increasing knowledge in the neurobiology of mindfulness. In this paper we review some of the most outstanding findings in this field, such as the effects of mindfulness on perception (openness), affective style (positive affect and approach mindset), immunity (enhanced) and empathy (increased). The research suggests that mindfulness practice activates several brain regions (like the prefrontal cortex) specialized in mediating human integrative functions. Moreover, prolonged mindfulness practice produces morphological changes in the cerebral cortex that correlate with changes in mental habits and character traits. Thus, the new field of Interpersonal Neurobiology, with its knowledge from different disciplines may even shape the clinical practice of psychotherapy.

Key Words: Mindfulness, Empathy, Immunity, Affective style, Prefrontal cortex, Traits, Psychotherapy, Interpersonal Neurobiology

The historical moment of mindfulness

At this historical crossroads of the beginning of the 21st century, we are witnessing the irruption of oriental practices of meditation into the theory and practice of psychology, psychotherapy and, in general, western science. This phenomenon, probably of an exceptional nature, is occurring as a result of at least three factors. Firstly, we find the spreading in the west of oriental philosophies and practices of meditation, which started in the second half of the 20th century with many young westerners travelling to Asiatic countries in search of the novelty and freedom promised by the philosophies and religions of the Far East. This phenomenon was surprisingly completed by another of a very different nature: numerous Tibetan monks fled their country due to the Chinese invasion of Tibet in 1951, and the establishment of the Autonomous Region of Tibet. This led to a diaspora which resulted in the creation of numerous Buddhist centres of Tibetan origin in all the great western cities. At present, increased communication between East and West is occurring in both directions, as part of the more general phenomenon usually known as globalisation. Both cultures are influencing and enriching each other, and within this influence there has been a propagation of some aspects of the traditions of meditation mainly of the different branches of Buddhism, Hinduism and Taoism.

Secondly, in western psychology a maturing of cognitive psychology and above all of cognitive therapies is occurring, in the context of what are known as third-generation therapies. Cognitive therapies constitute a fertile terrain where techniques related to mindfulness can be introduced and bear fruit. Though mindfulness is not an exclusively cognitive phenomenon, it is characterised by a strong component of this type, the cultivation of attention and of concentration. It is natural that as meditation of oriental origin became known in western psychological circles, cognitive psychologists should have perceived the enormous therapeutic possibilities of mindfulness. To this should be added the fact that in the oriental religious traditions the therapeutic nature of many of their practices is evident (it would be highly interesting to study the specifically therapeutic applications of many meditative practices). At present there exist various therapeutic techniques arising in western psychology, among which mindfulness plays a prominent role. The best known of these techniques are: Mindfulness Based Stress Reduction (MBSR: Kabat-Zinn, 1990); Mindfulness Based Cognitive Therapy (MBCT: Segal, Williams, Teasdale, 2002); Acceptance and Commitment Therapy (ACT: Hayes, Strosahl and Houts, 2005) and Dialectical Behavioral Therapy (DBT: Linehan, 1993; García Palacios, 2006), used in the treatment of the Borderline Personality Disorder. For an overall view of the present state of the application of mindfulness in psychotherapy, consult the book of Germer, Siegel and Fulton (2005): Mindfulness and Psychotherapy.

Thirdly, there is another aspect of western science which has reached a degree of maturity permitting a confluence with the practice of meditation, namely neuroscience, and particularly what is known as cognitive neuroscience and affective neuroscience. Advances in some methods for the study of the brain, such as neuro-imaging techniques and computerised processing of electroencephalographic signals, allow us to study the neurobiological correlates of thoughts and emotions with a degree of precision (both spatial and temporal) which would have been unimaginable 30 years ago. These techniques are permitting us to discover mind-brain interaction for the first time in the history of humanity, and they have begun to make it possible to know what happens in the brain when mindfulness is practised. This article will examine briefly some of this work

Closely related to neuroscience is the inter-disciplinary area that Siegel (2001) has called Interpersonal Neurobiology (IPNB), which studies the way in which interpersonal relationships affect brain development. Though, in principle, interpersonal relationships may seem far removed from meditation, in this article we shall see the deep relationship existing between them, which is established precisely through knowledge of the activities of certain cerebral circuits.

The peculiarity and novelty of the present situation lies precisely in the possibility of a dialogue arising between disciplines which formerly were quite isolated one from the other, such as neuroscience, development psychology, psychotherapy, and mindsight achieved by the practice of mindfulness. All these areas of knowledge strengthen each other, making it possible to reach much deeper levels of comprehension of the human reality than the isolated cultivation of any of these disciplines could offer. As a result of this interconnection, we are seeing the birth of a new interdisciplinary language to serve as a bridge between neurobiological knowledge and the clinical practice of psychotherapy, as it is possible to make a neurobiological interpretation of many of the psychological phenomena observed in the clinic. This recently acquired comprehension is leading not only to a new way of thinking by the therapist, but also to the patient thinking in a different way about his own mental functions and even about his own psychopathology.

What do we mean when we talk of mindfulness?

Mindfulness is not a modern discovery, though we are now living its rediscovery (and a certain re-encounter) in the framework of western culture. Mindfulness may have existed from the very moment when the first human brains started to transform the planet, although probably we shall never know when the earliest representatives of our species lived who practised some sort of mindfulness in a systematic manner. We do know that some 2,500 years ago the pinnacle of this practice was attained, specifically in the person of Siddharta Gautama (the Sakyamuni Buddha), who initiated a religious and philosophical tradition widely extended throughout the world (Buddhism), the cornerstone of which is, precisely, the practice of mindfulness. However, we are sure that mindfulness did not start with the Sakyamuni Buddha. He perfected to an extraordinary degree a procedure he had received from other masters and which probably had existed for a long time previously. For example, the origin of the Tibetan tradition of the Bön is situated some 17,000 years before Christ (Reynolds, 2005), and though no proofs to support this statement exist, we cannot rule out the possibility that some form of mindfulness was practised already by very early humans.

In reality, mindfulness is in itself something very simple and familiar, something we have all experienced on numerous occasions in our daily life. When we are conscious of what we are doing, thinking or feeling, we are practising mindfulness. The usual situation, however, is that our mind is wandering with no specific orientation, jumping from one image to another, from one thought to another. Mindfulness is a universal basic human capacity, consisting of the possibility of being conscious of the contents of the mind from one moment to another. It is the practice of self-awareness. The first effect of practising mindfulness is the development of the power of concentration of the mind. An increase in concentration brings with it serenity. And the cultivation of serenity leads us to an increased comprehension of reality (both external and internal), and brings us closer to perceiving reality as it is. The prolonged practice of mindfulness, in a favourable setting, also opens the door to the appearance of modified states of consciousness, but I shall not be considering these states in this paper.

From a scientific viewpoint, we could define mindfulness as a state in which the practitioner is able to maintain focus on an object for a theoretically unlimited period of time. (Lutz, Dunne and Davidson, 2007). Or, following Thich Naht Hanh (1987), mindfulness is keeping one’s consciousness alive to the present reality.

The existence of very different forms of meditation makes it extremely difficult to systematise or classify all possible manners of practising mindfulness, and in any case, it would exceed the limited framework of this paper. However, we can say that there is a certain consensus in distinguishing two components of mindfulness (Bishop et al. 2004). On the one hand there is the basic component, the fundamental characteristic of mindfulness, which consists of maintaining attention centred on the immediate experience of the present. It is, so to say, the central instruction that must be followed: being conscious of what is happening in the immediate present (though it may be possible to select different objects to centre one’s attention, an aspect I shall not pursue for now). The second component of Bishop’s definition is the attitude with which the first component is approached, in other words, how these experiences of the present moment are lived.

Regarding the attitude adopted towards the experience, Bishop et al. (2004) stress curiosity, openness and acceptance. Kabat-Zinn (1990) makes the following recommendations for the practice of mindfulness: non-judging, acceptance, beginner’s mind, non-striving, patience, letting go and trust. Siegel (2007) reduces the characteristics of a correct attitude to four: curiosity, openness, acceptance and love. In this review we shall comment on some of these basic attitudes of mindfulness.

Another aspect on which I should like to comment briefly is that of terminology. Most of the terms describing meditative states come from Pali and Sanskrit. Their translation into western languages in general and English in particular (the language into which they have mostly been translated), gives rise to a number of difficulties. A second obstacle comes from the translation from English into Spanish, as in this area of consciousness and mindfulness there are words in English which are difficult to translate into Spanish. These include the word mindfulness itself, awareness, insight and other related ones (see Prieto, 2007). In reality, as Vallejo (2006) says, mindfulness is a word that has no corresponding word in Spanish. In the Spanish version of this paper I have opted in most cases to use mindfulness, as opposed to atención plena (full attention), which though the most widely accepted translation does not reflect all the nuances of the English word. It is worth mentioning also that, in scientific contexts, the word mindfulness is preferred to meditation, which is more widely used on a popular level but has a vaguer meaning and includes a considerable variety of disparate practices.

One last point I should like to emphasise is that throughout this paper, unless the contrary is expressed, on referring to mindfulness I am referring to the practice of meditation most utilized at the present time by those in the west who practice meditation, which is Vipassana or Insight Meditation. The most widely used technique, especially at the outset, consists of centring attention on breathing, following the in–out rhythm of each breathing movement. When the mind moves away from its object, the subject returns gently to directing its attention towards breathing. And thus, again and again (see Brahm, 2006, for an excellent description of work with breathing). This part of the practice coincides with what are probably the three most-extended traditions in the west, the Theravada tradition of South-East Asia, the Zen tradition (originally from China) and the different schools of Tibetan Buddhism (for a more detailed description, see Lutz, Dunne and Davidson, 2007). There are many other practices, either specific to each tradition, or shared by several, but concentration on breathing is a common, basic element in the different Buddhist traditions.

We have to accept that, as Cahn and Polich (2006) recognised in their review of electrophysiological studies on meditation, no clear consensus about the underlying neurophysiological changes from meditation practice has emerged. This lack of consensus is not only due to the complexity of the neurophysiological processes involved. There are also methodological obstacles which for the time being prevent the maximum benefit being obtained from the exploratory techniques that are already available. As important obstacles we could mention: 1. The relative scarcity (or availability) of experimental subjects with a high level of meditative experience. 2. The number and diversity of meditation techniques, which makes it difficult to generalise from one study to another and aggravates the obstacle mentioned under number one above. 3. The inherent difficulty in dealing with a first-person phenomenon and that, even when two subjects believe they are practising in the same manner, it is possible that their minds are not situated in the same functional state. 4. The difficulty of finding appropriate control groups (see Lutz, Dunne and Davidson, 2007). All these obstacles can be overcome with scientific methodology, but for this purpose it is necessary to make a large number of studies, and this means that we shall have to wait for some time until sufficiently clear and definitive results are available. Even so, a good number of studies already exist which have explored the experience of mindfulness with a strictly scientific and neurobiological methodology. I shall now go on to describe the results of some of these studies, and precisely because it is not yet possible to approach this matter in a systematic and exhaustive manner, I have chosen a series of themes on which scientific knowledge already exists. They are classified into the following seven groups: Abandoning prejudices, opening oneself to novelty and knowing oneself; Mindfulness, prefrontal asymmetry and affective disposition; Mindfulness and immunity; Empathy and Mindfulness; Mindfulness, the transition from the state to the trait; Mindfulness and integration; The prefrontal cortex; and A tentative and hopeful conclusion.

Abandoning prejudices, opening oneself to novelty and knowing oneself

One of the fundamental attitudes in the practice of mindfulness is what Kabat-Zinn (1990) denominates beginner’s mind, doubtless in reference to the title of a well-known book by Suzuki (2000): Zen Mind, Beginner’s Mind. When mindfulness is practised imbued with this attitude, one tends to free oneself of all prior knowledge, of any acquired expectation, becoming open to the perception of reality as though it were the first time one was observing it. Everything is seen with fresh eyes, with the eyes of a beginner. This attitude makes it possible to discover aspects in things that previously had never been revealed to us, as we had approached them predisposed to perceive only what we were already expecting.

Fernando Pessoa gives a good description of how he lived his own personal lack of a beginner’s mind. Pessoa (1987) wrote, How I would love right now to be able to see all of this as one whose only relation to it was visual -- to view everything like an adult traveller who has just arrived at the surface of life! To not have learned ever since birth to attach given meanings to all of these things. To be able to see them in the expression they have on their own, quite apart from the expression that has been imposed on them. In this text, Pessoa senses and describes clearly what happens in the brain during development. This process which means that later on it is very difficult for us to see naked reality, without that impression that has been imposed on it. Pessoa, without realising it, yearned to be mindful, to practice mindfulness. The fact is that mindfulness does exactly what he, a century ago, thought that he needed, though he could not have known that it already existed in the world. Mindfulness, to use the more modern and more scientific language of Siegel (2007), entails the dissolution of the influences of prior learning on the sensation of the present.

Before examining what mindfulness does, let us first see what are those influences which obstruct perception of the present in its almost pure state. When the information coming from the sense organs makes its way through sensorial systems towards ever higher zones of the nervous system, it finds itself constrained and shaped by the nervous activity of extensive neuronal networks, which filter the information with criteria based on the prior life experience of each subject. This is expressed in the old Castilian refrain according to which everything depends on the colour of the glass through which it is seen. And the difficulty consists of “removing” this glass in order to see things without the deformation which its presence involves.

In neurophysiological terms, this influence that filters our perception of reality has been baptised by Engel, Fries and Singer (2001) as top-down processing, as opposed to bottom-up processing, which describes the entry of “fresh” information from the sensory organs. Engel, Fries and Singer (2001) write that, there is ample evidence that the processing of stimuli is controlled by top–down influences that strongly shape the intrinsic dynamics of thalamocortical networks and constantly create predictions about forthcoming sensory events. These descending influences exercise a kind of enslavement of the most local and emergent processes for elaborating information. These top-down processes exist, without doubt, because they possess a high survival value, since they make it possible to process and classify arriving information quickly, so facilitating the rapid taking of decisions necessary to survive. In this process of classification of information, which attempts to encase everything new in old categories and molds, it is inevitable that a large part of the entering material is lost, precisely the most novel part, which cannot easily be assimilated into the pre-established categories. The system acts by imposing a series of automatic filters which stress the already-known aspects of reality, and attenuate or eliminate completely its novel aspects. It is this colour of the glass through which we look that makes everything we see acquire a pre-established tone.

Top-down processes are very powerful when it comes to enslaving the live information which arrives from one moment to another, for as Siegel (2007) said, top-down influences that enslave bottom-up living have potent neural connectivity backing them up –much more powerful that the uncertainty of living in the here and now. Therefore, the information of the here and now (bottom-up) finds much greater difficulty in making its authentic message reach consciousness. This entering or primary information has been classified by Siegel (2007) into 8 senses or currents of sensory information, a highly useful classification, particularly when it comes to representing in our minds the information with which we deal when practising mindfulness. These eight senses, which are set out in Table 1, are: the five organs of the classic senses, interoception (including visceral and propioceptive sensations), comprehension of the mind (of one’s own mind and of that of others; mindsight, theory of mind) and, finally, the eighth sense, our relational sense, which informs us about the existence of resonance or dissonance in our interpersonal relationships and allows us to feel ourselves felt by others.

 

Senses	Information	Brain region
Sight, hearing, touch, taste and smell	Outer physical world	Posterior cortex(except smell)
Mindsight	Inner physical world	Somatosensory cortex, insula
Maintenance of the debt	Mind	Medial PFC
Relational sense:attunement	Interpersonal relationships	Mirror neurons and PFC

Table 1. The eight entrance routes of information to the consciousness space and most related brain structures
(after Siegel, 2007). (PFC: Prefrontal cortex).

Nowadays we are able to relate each of the eight currents of information to the corresponding areas of the brain. Without doubt, the best known are those of the five traditional senses which have their primary areas in the posterior regions of the cerebral cortex (except smell). The interoceptive sensations implicate the somatosensorial portion of the cortex and the median prefrontal zones, together with the insula, which maps visceral states. In states of self-consciousness the prefrontal medial cortex intervenes, as do the circuits of mirror cells (to which we shall return later) and the medial prefrontal cortex in interpersonal relationships.

In normal conditions, all this rich information which reaches superior levels of processing, is restricted by the downward influences, which play their simplifying and modulating role at all levels. Not only at higher levels of cognitive activities, such as thought and the emission of judgements, but also at lower levels such as the perception of the state of the body and emotional reactions. The wealth of nuances present in the initial sensorial levels is lost as the downward processes achieve their effect and assimilate their contents of information to pre-determined categories.

What can the practice of mindfulness do to change this situation? What does it mean that the beginner’s mind enters into action? What we do in mindfulness is to pay fuller attention to those eight currents of information that can accede to the space of consciousness (not all at the same time, obviously). By paying special, detailed attention to information as it enters, we start to make it more difficult for the downward processes to operate and we favour the arrival of a greater wealth of information to the prefrontal areas. The process of paying special attention to any of the eight currents of information requires that a part of the pre-frontal cortex, specifically the dorsolateral prefrontal cortex (DLPFC), is activated at the moment when it receives the information which is being privileged at that moment.

Once attention has been directed to one of the sensorial currents (with the participation of DLPFC), if at the same time we involve our capacity of self-observation, which is to say the metacognition which permits us to become conscious of the mental processes that are underway (and which implies the intervention of the more medial zones of the prefrontal cortex, including the orbitofrontal cortex), we shall have the opportunity to achieve a more flexible response, disconnecting (so to say) the automaticity which would have occurred in the absence of this conscious intervention. Here we can use the initials proposed by Siegel: YODA (You Observe and Decouple Automaticity).

It is interesting to point our that if this self-observation is continued for a considerable time (as is permitted by the constant daily practice of mindfulness), the moment arrives when we really can see or appreciate the characteristics of the top-down processes. If we return to the metaphor of the glass through which we look, we could say that the moment is reached when we are capable of seeing the glass. Before, the glass was invisible and we thought that what we were seeing was the direct reality. Now we realise that we were only perceiving the version of reality that we had constructed. Mindfulness permits us to perceive reality, on the one hand, and the way in which our mind deforms it, on the other. A particular case of this process of discovery can be seen in the process of knowing oneself.

Throughout our life, in our interaction with the world and with others, we have developed a way of being and acting, which makes up the personal identity of each one, an identity that accompanies us everywhere and which, with its advantages and drawbacks, helps us to adapt to the circumstances and survive. In a certain manner, it is a mask, shell or packaging, which prevents both ourselves and others from seeing what is situated most deeply, the substance of our true ego, what we could call ipseity. Lutz, Dunne and Davidson (2007) define this as the minimum subjective sense of ‘I-ness’ in experience, and as such, it is constitutive of a ‘minimal’ or ‘core self’ (core self in the sense of Damasio). Perhaps it would be appropriate to have recourse to poetry to transmit in a more intuitive manner this concept drawn from the experience of profound self-knowledge. Borges, in his book El otro, el mismo, in one of his few poems written in English, refers to that nucleus which I, in a certain manner, have saved-, the centre of the heart, which does not deal with words, which does not traffic with dreams and which has not been damaged by time or by adversities

The patient, repeated practice of mindfulness creates the necessary conditions to permit us to discover that relatively unknown nucleus of our own ipseity. The concentration and calm developed by practising mindfulness permit the discovery of how the mind functions, of the tricks and habits, of the subterfuges and lies with which the mind tries to deceive itself. It would be like clarifying the disturbed, muddy waters of a pond. If we leave it to become calm and the mud to settle as sediment, then we can see the contents and the banks of the pool. And if we look patiently and attentively, we shall eventually perceive the bed, the ipseity, the essence of what we are in reality.

Another aspect of opening up to novelty is the acceptance of uncertainty. Precisely because we have thrown off pre-judgements (the constrictions of top-down processing), we are open to anything that might appear. The mind remains without any expectations, but expectant. Ajahn Chah (2002) compares the experience lived by the observing mind, with that of someone who, while sitting in his home, receives various guests who come to visit him; the guests are the different mental states. The visitors always want something from the observer, but he limits himself to greeting them pleasantly, registering their presence, and letting them depart. He does not allow them to involve him in their affairs. The observer remains at his post, without moving. Finding nowhere to stay, the guests go away one after the other. The observer, repeating this experience time and again, learns to know his own mind and its states. In this way, the observer’s mind gains openness, flexibility and patience. Simply, it observes and learns.

Mindfulness, prefrontal asymmetry and affective style

One of the reasons for which the use of mindfulness is achieving clinical success is that it helps to re-establish emotional balance (as in the case of anxiety or borderline personality disorder), and because it favours positive states of mind and attitudes of approximation as opposed to those of avoidance. For this reason it has been used in the treatment of depression (Segal, Williams, Teasdale, 2002; Simón, 2002). At least one work has studied the direct effects of mindfulness on brain activity in relation to state of mind and to what has been called the affective style.

Richard Davidson et al. (2003) studied the cerebral activity of 25 normal experimental subjects (employees of a biotechnology company) who were submitted to a programme of MBSR (Mindfulness Based Stress Reduction) over a period of 8 weeks. The programme was carried out by J. Kabat-Zinn and consisted of weekly meetings of approximately three hours to practice meditation, a silent retreat during the sixth week, and homework including the practice of meditation for one hour every day, 6 days a week.

The EEG of the subjects was registered on three occasions: before the 8 weeks of treatment, immediately after the treatment and four months after ending the treatment. The electroencephalographic data were treated mathematically until obtaining a measurement of the cerebral activation of each hemisphere, right and left, which in its turn was used to calculate the degree of asymmetry existing between the two sides. It should be explained that, in this context, the activation of the zone under study is inversely related to the power of the alpha band (8-13 Hz). This means that the lower the power of the alpha band, the greater the cerebral activation, and vice-versa (Sutton and Davidson, 1999). This can also be expressed by saying that activation in a specific zone is measured by calculating the inverse of the power of the alpha band in that zone.

In the event, what Davidson et al. found was that the meditators, in comparison to the non-meditators, experienced a greater increase in left cerebral activation in the anterior and median zones, a pattern associated with the presence of a positive affective disposition. We could say that, after the period of 8 weeks of mindfulness, the meditators experienced a deviation of their cerebral activity towards the left.

These results should be interpreted in the light of extensive literature that has found a very consistent relationship between positive emotional states and a predominance of left anterior cerebral activation, and of negative affective states and the predominance of right anterior cerebral activation. However, the interpretation of this prefrontal asymmetry is more complex than it might seem at first sight. Greater activation of the left side is associated not only with a more positive frame of mind, but also with an increased reactivity to positive emotional stimuli, greater ability to handle negative states of mind and voluntarily to suppress negative affect. (The main references on these findings are summarised in Table 2).

Greater left prefrontal activation	Greater right prefrontal activation	References
Experience and expression of positive emotions and affects	Experience and expression of negative emotions and affects	Davidson & Irwin, 1999 Sutton & Davidson, 1997
Predisposition to positive mood states	Predisposition to negative mood states	Urry et al., 2004 Tomarken et al, 1992
Higher strength of the behavioral approach system	Higher strength of the behavioral inhibition system	Sutton & Davidson, 1997
Representation of desired goal states	Vigilant for threat related stimuli	Sutton & Davidson, 1997
Greater reactivity to positive stimuli	Greater reactivity to negative stimuli	Tomarken et al., 1990 Wheeler et al., 1992
Fast recovery following an aversive event		Jackson et al., 2003
Ability to regulate negative affect		Jackson et al., 2006
Eudaimonic, not hedonic well-being		Urry et al., 2004

Table 2. Prefrontal brain asymmetry and affect lateralization.
The table shows in its left column several positive cognitive and affective parameters that correlate with a greater left prefrontal activation. In general, negative cognitive and affective states are related to a greater right prefrontal activation (shown in the central column). In the last column on the right some relevant bibliographic references are shown.

The research of Urry et al. (2004) makes an interesting distinction between hedonic well-being and eudaimonic well-being. Hedonic well-being refers to those positive aspects of human life such as happiness, satisfaction with one’s own life and the frequency of pleasurable emotions. However, one speaks of eudaimonic well-being when, in addition to positive affection, there exist other qualities such as self-acceptance, high levels of autonomy and environmental mastery, and existence of a sense of life and of a purpose in life. The predominance of the activity of the left hemisphere would be more associated with eudaimonic well-being than with hedonic well-being.

It is interesting to stress that all these qualities, which are strengthened by the deviation of cerebral asymmetry towards the left, coincide with some aspects of the basic attitude recommended in the practice of mindfulness, namely with equanimity. An equable mind is one that does not discriminate, which does not make distinctions and which distances itself equally from attachment and aversion. The immediate consequence of equanimity is detachment, not clinging to things, letting go. Equanimity, however, does not denote indifference or abandonment, as mindfulness implies a basic attitude of respect and even love towards all beings (including oneself) and towards things in general. Thus, equanimity includes a positive frame of mind, without aversion and with a good capacity to face up to negative emotions and situations. An attitude, therefore, similar to one denoting the predominance of the activity of the left prefrontal cortex.

Mindfulness and immunity

The relationship outlined above between mindfulness and anterior cerebral asymmetry serves us as a bridge to approach another possible area of influence of the practice of meditation, namely the immune function.

In 1991, Kang et al. asked whether any relationship might exist between the prefrontal asymmetry profile and immunity mechanisms. They studied a group of 20 healthy women who showed extreme differences in prefrontal cortical asymmetry. They measured various immune parameters in these women to see whether any of them related to the type of cerebral asymmetry. Various immune indicators were studied, but the most significant discovery of the study by Kang et al. was that the women with the most extreme right frontal activation had lower levels of activity of the NK cells (natural killer cells). Here we can recall that cerebral asymmetry deviating to the right indicates a greater predisposition to depressive states of mind and greater vulnerability to negative affection. Therefore, this correlation between asymmetry and activity of the killer cells reveals a relationship between a specific pattern of cerebral activity and a specific immune response. The other immune parameters studied were not significantly different between the two groups of women, except that the right frontally activated subjects had higher immunoglobulin levels of the M class (IgM).

A few years later, in 1999, the subject was studied once again, but this time examining not only the differences in the basal state but also the response of the subjects to two types of stressful situations. One, of a natural character, the proximity of final examinations, and the other of an experimental nature, the viewing of films provoking positive or negative emotions. This study, by Davidson et al. (1999), confirmed that the subjects with greater activation of the right side displayed lower levels of basal function of the killer cells and, furthermore, that during the period of final exams they showed a reduction in the response of these killer cells. However, the subjects with greater cerebral activity on the left side showed a greater increase in the function of the killer cells. Though we do not yet understand the mechanism associating cerebral asymmetry with the behaviour of the killer cells, the relationship exists and constitutes one more proof of the existence of psychoneuroimmune mechanisms.

If we recall that in the section on cerebral asymmetry we said that the practice of mindfulness is capable of producing a lateralization of cerebral activity towards the left, it is logical to ask now whether such practice can also affect the immune system. This is what Richard Davidson et al. did in the work mentioned above (Davidson et al., 2003). In addition to registering the electroencephalographic activity, as we saw previously, all the subjects in the study (meditators and non-meditators) received an influenza vaccination. Between the 4th and the 8th week after the administration of the vaccination, the plasma levels of antibodies in the subjects were measured, and it was found that although in all cases these levels had risen, the subjects belonging to the group of meditators experienced significantly higher increases than those in the control group. Thus, meditation increases the production of antibodies. Furthermore, it is also of interest to note that the meditators who had experienced the greatest displacement towards the left in their cerebral electrical activity (between the first two consecutive measurements), were also those whose levels of antibodies most increased in response to the vaccinations. In other words, the magnitude of the increase in left lateral activity predicted the magnitude of the increase in antibodies, thus underlining the relationship between these two variables.

It should be mentioned that one of the mechanisms by means of which stress exercises its negative effects on health, is by means of an increase in cortisol and in its consequent immunosuppressive effects. It is possible that part of the beneficial effects of mindfulness on immunity are due to the attenuation of the secretion of cortisol in response to stress (Michaels, 1979). However, in the study of Kang et al. (1991), for example, the levels of cortisol did not differ between the two groups of subjects, and therefore the differences in the activity of the killer cells could not be attributed to a modification in the levels of this hormone. Other still-unidentified mechanisms must have played a role in the production of the results.

These findings represent no more than a beginning in the study of a relationship that might prove extraordinarily fruitful: the possibility of influencing the immune system through meditation. Given the transcendence of the immune mechanisms in the maintenance of health and the high number of pathologies in which immune alterations exist, it is obvious that the possibility of influencing immunity in a positive manner could open up new paths in the therapy of these processes. By way of example, think of the auto-immune disorders, of all types of infection and of tumoral processes, among other pathologies especially related to immunity.

Empathy and mindfulness

The relationship between empathy and mindfulness is very old, though its neurobiological implications are much more recent. One of the classic Buddhist meditations is that on metta, a Pali word translated by loving-kindness or compassion (compassion, in English, has the drawback of being confused on occasion with pity, a state of mind far removed from metta). In this meditation the subject uses various techniques to foment in himself feelings of compassion and love towards other people and towards himself (Salzberg, 1995; Brahm, 2006).

In 2004, Lutz et al. studied electroencephalographic activity in experimental subjects who received the instruction to generate in themselves a state of pure compassion or unrestricted readiness and availability to help living beings. As experimental subjects they used practitioners of the Tibetan Kagyu and Nyingma traditions who had ample experience of meditation throughout their lives (between 10,000 and 50,000 hours). As a control group they used volunteers without experience of meditation, whom they trained in the production of this state for a period of only one week. The most striking result was that the group of subjects with experience of meditation developed oscillations of greater magnitude in the band of gamma frequencies (25-42 Hz), above all in the fronto-parietal lateral electrodes, and that the generation of gamma oscillations was much greater in the practitioners than in the control group. The increase found in neuronal synchronization can be interpreted as an increase both in the number of neurons recruited during the activity, and in the temporal precision of the thalamo-cortical and cortico-cortical discharges of these neurons. Furthermore, both groups were clearly differentiated not only during the meditation, but also during the periods before and after meditation, suggesting that the activity of meditation induces long-term changes in cerebral functioning. The most important conclusion reached by the authors of this study is that attentional and affective processes are skills that can be trained, though we still do not understand the exact functional role that these modifications in the gamma frequency play in the brain.

However, it has been a series of neurobiological discoveries made in an area apparently with little relationship to compassion, which have helped to bring about a notable change in our view of the theme of empathy. In 1996, a group of Italian researchers (Rizzolati, Fadiga, Gallese and Fogassi, 1996; Gallese, Fadiga, Gogassi and Rizzolati, 1996) described in the premotor cortex of the macaque a type of neurone that discharged not only when the animal was executing motor actions directed to a goal, but also when the animal was observing other individuals carrying out these actions. These neurons were called mirror neurons by their discoverers. Subsequent studies have found mirror neurons in other cerebral zones and their existence has also been demonstrated in human beings though, for obvious reasons, in humans it is necessary to employ other more indirect techniques than those used with monkeys: Rizzolatti and Craighero (2004), Rizzolatti (2005).

So important a personality in neuroscience as Vilayanur Ramachandran, has not doubted in classifying the discovery of mirror neurons as the most important event of the decade, and he predicts that mirror neurons will do for psychology what DNA for biology: they will provide a unifying framework and help explain a host of mental abilities that have hitherto remained mysterious and inaccessible to experiments (Ramachandran, 2000). Probably it is still too soon to envision all the implications that mirror neurons will have in the understanding of cerebral functions and of human behavior. Ramachandran goes so far as to make them co-responsible for the great leap forward made by the human species some 40,000 years ago as manifested by the birth of the use of tools, of art, of mathematics and even of some aspects of language. There can be no doubt that networks of mirror neurons are the neural substratum which makes possible the understanding of the mind of others (the theory of mind or the vision of the mind) and of simulation, two activities in which human beings are extraordinarily efficient.

When we observe a movement in another person, the same motor circuits are activated in our brain as we would need to activate if we had to carry out the movement ourselves (Gallese, 2003). Thus, in a certain manner, we perceive the movement of others through ourselves. There is a resonance of our nervous system with the nervous system of the subject we are observing. As Blakemore and Decety (2001) say, we understand the actions of others through our own motor system. Or, in the words of Gallese (2003), to perceive an action is equivalent to internally simulate it. This internal simulation is also the origin of our comprehension of the behavior of others, which is originated as we now go on to describe. Our brain stores the information pertinent to the internal sequences of its own actions: intention ? motor order ? action ? sensorial (and other types of) consequences. When we observe motor actions in others, in our brain the same circuits are activated that would be necessary for us to carry out the same action. It is then that we can consult our memory (not necessarily in a conscious manner) on what intentions are related to the carrying out of such acts, and by this indirect route we have access to understanding the minds of others. Thus, the mere observation of the motor acts of other living beings allows us to infer not only their intentions, but also the mental states that normally underlie such intentions. This inference of the mind of others is what has been called theory of mind (see Obiols and Pousa, 2005) and implies the activation of the left medial prefrontal cortex. Blakemore and Decety (2001), in their explanation of the neurological mechanisms of the comprehension of the actions of others, offer the example of what happens when we observe someone taking a glass of water and lifting it to their lips. The observation of this behavior activates in our brain the motor and sensorial circuits related to this act (which we have performed thousands of times), and immediately we imagine what is the intention and the motivation of the person we see performing the action. In this way, we can imagine their mental state; in this case, their need to quench their thirst.

Iacoboni et al. (2005), by means of a series of ingenious experiments undertaken with functional magnetic resonance, demonstrated that the codification of intention associated with the actions of others is related to an increase in the neuronal activity of the lower frontal cortex, and they reached the conclusion that this codification is based on the activation of a neuronal chain formed by mirror neurons coding the observed motor act and by ‘‘logically related’’ mirror neurons coding the motor acts that are most likely to follow the observed one, in a given context. To ascribe an intention is to infer a forthcoming new goal, and this is an operation that the motor system does automatically. Iacoboni et al. suggest (as their own experience and various laboratory experiments confirm) that we ascribe intentions to the actions we observe in a quite involuntary manner, practically without proposing to do so.

It is logical to ask ourselves whether, on perceiving the emotions of others, similar mechanisms are set in motion to those occurring with motor acts and with intentions. Everything suggests that this is the case. In other words, that empathy, the comprehension and even the living of the same emotion as the other person experiences, is set in motion by imitation mechanisms which make similar emotions to those of the subject observed appear in the observer. For example, in the case of the recognition of facial emotions, Adolph (2002) describes how from the amygdala and the orbito-frontal cortex nervous impulses are generated which activate certain components of emotional response (among them, changes in facial expression) and that this mechanism might contribute to the generation of knowledge about another person’s emotional state, via the process of simulation, and would draw on somatosensory related cortices in the right hemisphere for representing the emotional changes in the perceiver. In a similar manner to motor acts, the observation of emotions generates emotional changes in the observer which allow him to comprehend the emotion being observed.

Therefore, it is evident that the human brain comes prepared to interrelate socially with others, to understand their actions, the intentions that guide them and the motivations that drive them. And also to feel their emotions. As Siegel (2001) proposes, the brain is structured with an innate capacity to transcend the boundaries of the skin of its own body in integrating itself with the world, especially the world of other brains.

To follow Decety and Jackson (2004), it is of interest to point out that, at least in human beings, the processes of empathy are not limited to the activation of mechanisms of shared representation (which we have just described), based on the coupling of perception with the action. Two other components also take part. Firstly, the existence of a consciousness of the difference between one’s own self and the self of the other, a distinction in which the medial prefrontal cortex and the lower parietal lobe participate. And the third component mentioned by Decety and Jackson is the mental flexibility to adopt the perspective of the other (medial prefrontal cortex, frontopolar cortex and posterior cingulate) and set in motion mechanisms of emotional regulation which attenuate the emotional response to the suffering or emotion we are observing (implication of the orbitofrontal cortex and of the ventromedial prefrontal cortex).

After this outline of the neurobiological mechanisms of empathy, let us now return to relating this mental state to mindfulness. Our comments will be limited to two types of link, starting with the most obvious one. As explained at the beginning of this section, a typical exercise of some meditative traditions consists precisely in specific training in compassion and sympathy for others, pure compassion, as mentioned when commenting on the work of Lutz et al. (2004). In this case, the researchers did not make use of neuroimaging, but they did register the electrical activity of the brain, and all we can say is that the gamma synchronization observed is probably related to the activity of the neural circuits involved in the above-mentioned empathic responses. It must be said that, in any case of mindfulness, one requires an attitude of affective approach and sympathy or love towards the object on which attention is centred. In other words, mindfulness implies empathy, whatever the object towards which it is directed. It should remembered that the mere fact of focussing attention on something, if done with a hostile or angry attitude, is not considered mindfulness.

Another less obvious aspect of the mindfulness-empathy relationship is the one suggested by Siegel (2007), which we could call the hypothesis of auto-empathy or of internal attunement. The systems of empathy described above allow links of communication to be established between individuals which involve a certain class of resonance or attunement between their respective nervous systems. A person feels felt by the other, and vice-versa. If the valence of this connection is positive, the safety-threat detection system (what Stephen Porges – 2003a – has called neuroception) registers the presence of a secure relationship, and the autonomous nervous system of the subject responds in a receptive and open manner in the presence of the other person (for an overall understanding of this construct, see the polyvagal theory of Porges, 2003b). In these circumstances it is possible for social links to be established between individuals, activating what Porges calls the social engagement system. Proximity, facial communication and the reaction of the autonomous nervous system to signals received are key components of the favourable (or unfavourable) response of the subject. If it is favourable, a state that Porges calls love without fear develops. What Siegel suggests is that these neural systems which normally sustain experiences of attunement and resonance with other people, in the practice of mindfulness will return reflexively upon the subject himself to develop self-engagement (in the place of the social engagement mentioned above), a relationship of love without fear of the subject’s own experience. Thus, in mindfulness we are developing empathy, comprehension, love, compassion, with our own experience and our own self. We have a neuroception of safety with ourselves and consequently we connect, feel in tune and resonate with our most authentic ego (evidently, within the limitations imposed by the level of self-awareness of each one at any given moment).

It is easy to deduce that the encouragement of this emotion of self-empathy could have a clear therapeutic value, especially when self-destructive feelings play a prominent role among the pathological manifestations. In mindfulness, we can change perspective and observe ourselves and experience ourselves as though we were other. In this process of self-knowledge we can open ourselves without barriers to information received through all the channels mentioned in Table 1 and enter into resonance with the varied aspects of oneself, integrating them into our consciousness and fomenting towards them feelings of sympathy and love.

Finally, it is also possible to encounter antecedents for this attitude of social engagement in oriental meditative practices. A well-known Tibetan practice is Tonglen (to send and to receive), where the subject assumes the suffering of another or others and sends them his love and compassion (see Chodron, 1996). One of the variations of Tonglen consists of practising it with oneself, taking one’s own suffering and sending love and compassion to oneself. This is an extreme form of the self-engagement described by Siegel.

Mindfulness: the transition from the state to the trait

There exists sufficient consensus to affirm that mindfulness, in any of its forms of expression, is a mental state. Siegel (1999) defines mental state as the total pattern of activations in the brain at a particular moment in time, and he points out that a mental state has two basic functions: to coordinate activity in the moment and to create a pattern of brain activation that can become more likely in the future. With the repetition of a mental state, we are increasing the probability of similar states being produced with ever-greater frequency, and this is equivalent to saying that what at first was a state of mind localized in time in a circumscribed moment, can become an enduring trait of the subject.

This is exactly what would appear to happen with the practice of meditation. Concentration of attention from moment to moment, which at first requires a considerable effort (for example, to persist in attention to breathing, constantly avoiding the intrusion of thoughts or emotions), in time becomes an automatic habit hardly requiring any effort. This transition from attention to the present with effort, to attention to the present without effort, is what separates the beginner from the experienced meditator. (From the neurobiological standpoint, the recruitment of one’s own attention in the initial states characterised by effort, requires the implication of the dorsolateral prefrontal cortex, as we shall see shortly, while the maintenance of conscious attention without effort – trait – would be related to the activity of the medial prefrontal cortex, a highly integrating region on the functions of which we shall insist later). In the ideal case, one reaches being in a state of continuous presence, of full attention during the whole day, whatever the activity being undertaken. What at first was a transitory state is transformed with practice into a trait.

Does any scientific evidence exist that this is so? Do we have any experimental data demonstrating that with the practice of mindfulness we are producing lasting cerebral changes? At least two very recent publications would allow us to answer these questions affirmatively. The first is the paper of Sara Lazar et al. (2005) of the Massachusetts General Hospital. This is the first work to demonstrate the existence of structural changes in the brain with the practice of meditation. In this work the brains of 20 western volunteers were studied with magnetic resonance: they had ample experience (an average of 9 years) of Insight Meditation or Vipassana meditation. In this form of mindfulness, the attention is focussed specially on interoceptive stimuli (such as breathing), but with the increase of the practitioner’s experience its scope is widened to thoughts, emotions and even external stimuli. The most striking result of Lazar’s study is that in certain zones of the brains of the meditators there was a greater thickness of cerebral cortex (compared to the brains of adequate control subjects). The zones affected were the insula of the right hemisphere (an area associated with interoceptive activity and the consciousness of breathing) and the right prefrontal cortex (areas 9 and 10 of Brodmann), which are associated clearly with sustained attention. It remains to be established to which part of the nervous tissue the increase in thickness should be attributed, since the technique used did not permit this. It might be due to an increase in arborisation of the neurons, to an increase in the volume of the glia, or to an increase in the vascularization of the zone. This work of Lazar et al. demonstrates that the experience of mindfulness not only provokes transitory functional changes, but also leaves structural imprints in the brain. This means, as outlined above, that the experience of meditation, if it is sufficiently prolonged, ends by producing changes of trait, not merely of state.

The second study reinforcing the idea of the transition from the state to the trait is a very recent work by Brefczynski-Lewis et al. (2007). These authors used functional magnetic resonance to study cerebral activity in two groups of meditators, some experts and others novices, who practised concentration of attention on a small point on a screen. One of the most important conclusions of this study is that the activation of neuronal networks related to mechanisms of sustained attention is produced in a different manner, depending on the meditative experience of each of the sub-groups into which the sample was divided. The expert meditators, with some 19,000 hours of practice, presented more activation than the newer subjects, but the subjects with the maximum number of hours of practice (some 44,000) again presented a lower activation. This means that an inverted U appears in which the subjects with an intermediate number of hours of practice are those who show most activation. This suggests that changes of neural plasticity have occurred in the brains of the most experienced meditators, which have allowed them to attain similar states of concentration to the intermediate practitioners, but without needing to make such an effort of attention. The more expert one is, the less effort is necessary to attain the state of concentration, as the necessary neural networks are anatomically more robust. Another of the interesting findings of this study is that in the subjects with most hours of meditation, a passing activation of the dorsolateral prefrontal cortex (DLPFC) was found, a region with executive capacity, related to the production of states of alert and monitorization of attentional activation (Raz and Buhle, 2006). The activation of this zone lasted for some 10-20 seconds at the start of the meditation and then returned to the basal line. However, the meditators with fewest hours of practice showed a longer and more sustained activation of this zone, indicating that they required a more prolonged effort to maintain attention in the present.

Therefore, neurobiological research confirms that by the practice of mindfulness we are propitiating an immediate change in our mental state, and that if the practice is prolonged over a good deal of time, what at first was no more than a transitory functional modification is converted into permanent changes in the cerebral structure, changes implying modifications which are also lasting in the subject’s manner of being and reacting, the change of a trait in his personality.

Mindfulness and integration: The prefrontal cortex

In all the neuroimage studies of brain activity related to meditation (see, for example, the review of Cahn and Polich, 2006), there is a zone that usually stands out due to its important participation. This is the prefrontal cortex. Especially in its most anterior zones (areas 10 and 32 of Brodmann), this prefrontal cortex has experienced a large increase in size in the human species compared to the size of the prefrontal cortex of the monkeys. However, it is not so clear that this increase in humans is so spectacular when we compare it to the prefrontal cortex of the great apes (Frith and Frith, 2006). I shall comment briefly on this cerebral structure and its relationship to the practice of mindfulness.

It is usual to include under the term ‘prefrontal cortex’ those regions of the frontal lobe situated in front of the motor and pre-motor areas. Generally, the terms prefrontal cortex and frontal lobe are used without any distinction to refer to these structures (Wheeler, Stuss and Tulving, 1997). The functions of the prefrontal cortex are always of a supervisory nature (such as language, motility or vegetative functions), controlling activities carried out by other cerebral structures situated more caudally in the nervous system. The prefrontal functions, precisely due to their character of integration of very diverse processes such as thought, behavior or affectivity, do not prove easy to systematise. Stuss and Benson (1986) distinguished three levels in the functions of the prefrontal cortex. The first level is that of the integration and organization of information proceeding from other posterior cerebral regions, with the purpose of forming meaningful representations. The integrated information refers to cognitive, affective and motor aspects. The second level deals with what are known as executive functions, those which direct and control the integrated behaviors of the organism (especially in response to new situations), which require creative solutions and cannot be dealt with using the automatised mechanisms of lower rank. The third level deals with self-awareness, the consciousness of one’s own self and of one’s own mind. In recent years this function has been extended also to knowledge of the mind of others, the so-called theory of mind (see Frith and Frith, 2003; Frith and Frith, 2006, for recent revisions).

It is also appropriate to make use of an anatomical division of the prefrontal cortex to orientate us in this field, which is of undoubted importance for the understanding of human behavior. In the lateral portion, notice particularly the dorsolateral portion of the prefrontal cortex (DLPFC), mentioned above, related to working memory and attention. In what can be grouped together under the name of medial prefrontal cortex (the most important area for integration), various regions can be distinguished in their turn: the medial region as such (in which various zones can be distinguished), the ventral portion and the orbito-frontal portion. The anterior part of the cingulus (ACC) is usually considered functionally as a prolongation of the medial portion, immediately behind which it is located. Though in the limited space of this article it is impossible to go fully into the functional complexity of the prefrontal regions (the reader can find a brief summary of these in Table 3, and some bibliographical references that are useful for guidance on this subject), it should be stressed that in the prefrontal cortex we find the anatomical substratum of the principal integrating functions of the human brain. Therefore, this area must be understood when dealing with the concepts and mental schemes which are beginning to take shape as the protagonists of a psychotherapy based on the knowledge of cerebral functioning and which form part of what has been called Interpersonal Neurobiology.

Region	Function	References
Medial frontal cortex	Metacognition
Posterior region	Represents and updates the value of possible future outcomes in order to regulate behavior	Amodio & Frith, 2006
Anterior region	Monitoring of one’s own emotional state, person perception and mentalizing	Amodio & Frith, 2006
Orbital region	Represents and updates the value of possible future outcomes	Amodio & Frith, 2006
ACC Anterior cingulate cortex	Attention, response selection, assessing painful stimuli, affective changes	Devinsky, Morrell & Vogt, 1995
OFC Orbitofrontal cortex	Decision making. Links the current incentive value of reinforcers to cues. Modulation of the autonomic nervous system. Response flexibility	Bechara, Damasio & Damasio, 2000 Schoenbaum & Setlow, 2001 Schore, 1994 Nobre et al., 1999 Siegel, 1999
VPFC Ventromedial prefrontal cortex	Regulation of negative affect	Urry et al.. 2006
DLPFC Dorsolateral prefrontal cortex (particularly the right side)	Working memory organization. Activation and regulation of arousal levels	Petrides, 2005 Blumenfeld & Ranganath, 2006 Raz & Buhle, 2006

Table 3. Main regions of the PFC and associated functions.
The table shows some of the functions related to different parts of the prefrontal cortex and relevant references.

Another way to systematise the functional role played by the prefrontal cortex is to enumerate a series of functions, which are correlated to the activity of this part of the brain. This is what Siegel does in his book The Mindful Brain (2007), in which he lists nine functions of the medial prefrontal cortex. These are as follows: body regulation, attuned communication with other minds through resonance processes, emotional balance, response flexibility, empathy, insight or self-knowing awareness, fear modulation, intuition and morality. Siegel considers that all these functions are related to mindfulness (in this article, most of them have been mentioned), and furthermore that the first seven are also connected to secure parent-child attachment. This confluence does no more than corroborate what has been described in the chapter on empathy: if an interpersonal attunement occurs in the secure attachment (between parents and children, between patient and therapist or between teacher and student), in the case of mindfulness there is an internal attunement with oneself, in which the integration of all the neural systems is facilitated so that the nervous system as a whole functions in a coherent manner. As Siegel puts it, mindfulness may nurture healthy relationships through a number of mechanisms including enhanced empathy, emotional balance, response flexibility, and an approach mindset.

A tentative and hopeful conclusion

My hypothesis, in view of the neurobiological knowledge described in this paper, is that with the prolonged practice of mindfulness, lasting neurological changes are produced in various areas of the brain crucial for processes of integration, changes which going beyond the specific activity that provoked them, end up by modifying a considerable number of the individual’s forms of behaviour and of reaction. In this way they have a multiplier effect on his life and interpersonal relationships, due precisely to the great repercussion that cerebral integrating functions have, by their very nature. A sporting simile, which seems appropriate if somewhat rough, would be to compare meditation with the practice of gymnastics. The musculature acquired within the walls of the gymnasium may have notable repercussions on the individual’s performance in various sporting activities (football, swimming, athletics, etc.), apparently far removed from the exercises which originally gave rise to the muscular development.

In this way, it is possible to understand the potential importance of meditation for many human activities in which the optimum development of the nervous system plays a crucial role. It is of interest not only in psychotherapy, but also in the world of education (Langer, 1997). We may recall that, over a century ago, William James said that the cultivation of attention would be l’éducation par excellence. Mindfulness is already beginning to be applied to children of school age, though for the time being its quantitative repercussion is fairly limited.

Obviously, many of these reasonable suppositions require more firmly-based experimental confirmation than we have available at present. Nonetheless, I believe that we are already in a position to state that we are facing the birth of a phenomenon that will modify substantially the manner in which many human activities are approached, including psychotherapy, which is what most interests us in this context.

References

Adolphs R (2002). Neural systems for recognizing emotions. Current Opinion in Neurobiology, 12: 169-177.

Bechara A, Damasio H & Damasio AR (2000). Emotion, decision making and the orbitofrontal cortex. Cerebral Cortex, 10(3):295-307.

Bishop, S. R., Lau, M., Shapiro, S., Carlson, L., Anderson, N. D., Carmody, J., Segal, Z. V., Abbey, S., Speca, M., Velting, D. & Devins, G. (2004). Mindfulness: A Proposed Operational Definition. Clinical Psychology: Science and Practice, 11: 230-241.

Blakemore S-J & Decety J (2001). From the perception of action to the understanding of intention. Nature Reviews Neuroscience. 2: 561-567.

Blumenfeld R S & Ranganath C (2006). Dorsolateral Prefrontal Cortex Promotes Long-Term Memory Formation through Its Role in Working Memory Organization. The Journal of Neuroscience, 26 (3):916 –925.

Brahm A. (2006). Mindfulness, Bliss and Beyond. Wisdom Publications. Boston.

Brefczynski-Lewis JA, Lutz A, Schaefer HS, Levinson DB & Davidson RJ (2007). Neural correlates of attentional expertise in long-term meditation practitioners. PANAS, 104: 11483-11488.

Chah A (2002). Food for the Heart. The Collected Teachings of Ajahn Chah. Wisdom Publications. Boston.

Chodron P (1996). Awakening lovingkindness. Shambhala Publications. Boston.

Davidson RJ, Coe CC, Dolski I y Donzella B (1999). Individual Differences in Prefrontal Activation Asymmetry Predict Natural Killer Cell Activity at Rest and in Response to Challenge. Brain, Behavior and Immunity, 13: 93-108.

Davidson R J, Kabat-Zinn J, Schumacher J, Rosenkranz M, Muller D, Santorelli S F, Urbanowski F, Harrington A, Bonus K & Sheridan J F (2003). Alterations in Brain and Immune Function Produced by Mindfulness Meditation. Psychosomatic Medicine, 65: 564-570.

Decety J & Jackson P L (2004). The Functional Architecture of Human Empathy. Behavioral and Cognitive Neuroscience Reviews, 3 (2): 71-100.

Devinsky O, Morrell M J & Vogt B A (1995). Contributions of anterior cingulate cortex to behaviour. Brain, 118: 279-306.

Engel A K, Fries P & Singer W (2001). Dynamic predictions: Oscillations and synchrony in top-down processing. Nature Reviews Neuroscience, 2: 704-716.

Frith U & Frith CD (2003). Development and neurophysiology of mentalizing. Phil. Tran. R. Soc. Lond. B 358: 459-473.

Frith CD & Frith U (2006). The Neural Basis of Mentalizing. Neuron, 50: 531-534.

Gallese V (2003). The Roots of Empathy: The Shared Manifold Hypothesis and the Neural Basis of Intersubjectivity. Psychopathology, 36: 171-180.

Gallese V, Fadiga L, Fogassi L & Rizzolati G (1996). Action recognition in the premotor cortex. Brain. 119 (2):593-609.

Germer C K, Siegel R D & Fulton P R (2005). Mindfulness and Psychotherapy. New York: Guilford Press.

Hanh T N (1987). The Miracle of Mindfulness. Beacon Press. Boston.

Hayes S, Strosahl K & Houts A (2005). A practical guide to acceptance and commitment therapy. New York: Springer.

Iacoboni M, Molnar-Szakacs I, Gallese V, Buccino G, Mazziotta JC et al. (2005). Grasping the intentions of others with one’s own mirror neuron system. PloS Biol. 3(3): e79.

Jackson DC, Mueller CJ, Dolski I, Dalton KM, Nitschke JB, Urry, HL, Rosenkranz MA, Ryff CD, Singer BH & Davidson RJ (2003). Now you feel it, now you dont: Frontal Brain Electrical Asymmetry and Individual Differences in Emotion Regulation. Psychological Science, 14 (6): 612-617.

Jackson DC, Jackson CAB, Schwab G & Davidson RJ (2006). Resting frontal brain asymmetry as a predictor of ability to regulate negative affect. SPR Abstracts, S11.

Kabat-Zinn, J. (1990). Full catastrophe living. Using the Wisdom of Your Body and Mind to Face Stress, Pain, and Illness. Delta Book Publishing. New York.

Kang D-H, Davidson R J, Coe C L & Ershler W B (1991). Frontal Brain Asymmetry and Immune Function. Behavioral Neuroscience, 105 (6): 860-869.

Langer E J (1997). The power of mindful learning. Da Capo Press, Cambridge, MA.

Lazar S. W., Kerr, C. E., Wasserman, R. H., Gray, J. R., Greve, D. N., Treadway, M. T., McGarvey, M., Quinn, B. T., Dusek, J. A., Benson, H., Rauch, S. L., Moore, C. I. & Fischl, B. (2005). Meditation experience is associated with increased cortical thickness. Neuroreport; 16 (17): 1893-1897.

Linehan M (1993). Cognitive-behavioral treatment of borderline personality disorder. Guilford Press. New York.

Lutz A, Dunne JD & Davidson R J (2007). Meditation and the Neuroscience of Consciousness: An Introduction. En: Zelazo, P., Moscovitsch, M., & Thompson, E. The Cambridge Handbook of Consciousness. Cambridge University Press. Cambridge, New York.

Lutz A., Greischar L., Rawlings N., Ricard M. & Davidson R. (2004). Long-term meditators self-induce high-amplitude gamma synchrony during mental practice. PNAS, 101: 16369-16373.

Michaels R R, Parra J, Mccann D S & Vander A J. (1979). Renin, Cortisol, and Aldosterone During Transcendental Meditation. Psychosomatic Medicine, 41 (1): 50-54.

Obiols J E & Pousa E (2005). La Teoría de la Mente como módulo cerebral evolutivo. En: J. Sanjuán y C. J. Cela. La Profecía de Darwin. Ars Medica. Barcelona.

Pessoa F (1996). The Book of Disquietude. The Sheep Meadow Press. Riversdale-on-Hudson, New York.

Petrides M (2005). Lateral prefrontal cortex: architectonic
and functional organization. Phil. Trans. R. Soc. B 360, 781–795.

Porges S W (2003a). Social Engagement and Attachment. A Phylogenetic Perspective. Ann. N.Y. Acad. Sci. 1008: 31-47 (2003).

Porges S W (2003b). The Polyvagal Theory: phylogenetic contributions to social behavior. Physiology & Behavior, 79: 503-513.

Reynolds, J. M. (2005). The Oral Tradition from Zhang-Zhung. Vajra Publications. Thamel, Katmandú.

Ramachandran V S (2000). Mirror neurons and imitation learning as the driving force behind "the great leap forward" in human evolution. Edge 69. http://www.edge.org/

Raz A & Buhle J (2006). Typologies of attentional networks. Nature Neuroscience, 7: 367-379.

Rizzolati G (2005). The mirror neuron system and its function in humans. Anat Embryol (Berl), 210 (5-6): 419-21.

Rizzolatti G & Craighero L (2004). The mirror-neuron system. Annual Review of Neuroscience, 27: 169-192.

Rizzolati G, Fadiga L, Gallese V & Fogassi L (1996). Premotor cortex and the recognition of motor actions. Cognitive Brain Research, 3 (2): 131-141.

Salzberg S (1995). Lovingkindness: The Revolutionary Art of Happiness. Shambhala Publications. Boston.

Schoenbaum G & Stelow B (2001). Integrating orbitofrontal cortex into prefrontal theory: common processing themes across species and subdivisions. Learning and Memory, 8(3):134-47.

Schore A N (1994). Affect Regulation and the Origin of the Self. Lawrence Earlbaum, Hillsdale.

Segovia S (2004). Meditación y psicoterapia. En: Crecimiento Personal: Aportaciones de Oriente y Occidente. Ed. Mónica Rodriguez-Zafra. Desclée de Brouwer. Bilbao.

Segal Z V, Williams JMG & Teasdale JD (2002). Mindfulness-based cognitive therapy for depression: A new approach to preventing relapse. New York: Guilford Press.

Siegel D J (1999). The Developing Mind. The Guilford Press. New
York. London.

Siegel D J (2001). Toward an interpersonal neurobiology of the developing mind: attachment relationships, “mindsight,” and neural integration. Infant Mental Health Journal, 22 (1–2): 67–94.

Siegel D J (2007). The Mindful Brain. Norton & Company. New
York. London.

Simón V (2002). La depresión como oportunidad. En: Depresión. Estado Actual. Ed.: Federico Pallardó. Fundación Valenciana de Estudios Avanzados. Valencia.

Stuss D T & Benson D F (1986). The frontal lobes. Raven Press. New York.

Sutton S K y Davidson R J (1999). Prefrontal Brain Asymmetry: A Biological Substrate of the Behavioral Approach and Inhibition Systems. Psychological Science, 8 (3): 204-210.

Suzuki, S. (2000). Zen Mind, Beginner's Mind. Weatherhill. New York.

Thich Nhat Hanh (2000). El corazón de las enseñanzas de Buda. Oniro. Barcelona.

Tomarken A J, Davidson R J & Henriques J B (1990). Resting frontal brain asymmetry predicts affective responses to films. Journal of Personality and Social Psychology, 59: 791-801.

Tomarken A J, Davidson R J Wheeler R E & Doss R C (1992). Individual differences in anterior brain asymmetry and fundamental dimensions of emotion. Journal of Personality and Social Psychology, 62: 676-687.

Urry HL, Nitschke JB, Dolski I, Jackson DC, Dalton KM, Mueller CJ, Rosenkranz MA, Ryff CD, Singer BH & Davidson RJ (2004). Making a Life Worth Living. Neural Correlates of Well-Being. Psychological Science, 15 (6): 367-372.

Urry HL, van Reekum CM, Johnstone T, Kalin NH, Thurow ME, Schaefer HS, Jackson CA, Frye CJ, Greischar LL & Alexander AL (2006). Amygdala and Ventromedial Prefrontal Cortex Are Inversely Coupled during Regulation of Negative Affect and Predict the Diurnal Pattern of Cortisol Secretion among Older Adults. The Journal of Neuroscience, 26 (16): 4415-4425.

Wheeler MA, Stuss DT & Tulving E (1997). Toward a Theory of Episodic Memory: The Frontal Lobes and Autonoetic Consciousness. Psychological Bulletin, 121: 331-354.