IX

WHAT IS TO BE DONE? − Motor control and behavior

Eventually, let us stop looking for meta-spaces in the brain, and get back to the classical approach: the brain is not there to think, it is there to act. Indeed, even frogs have it, and they do not think so much, do they?

A crucial aspect of evolution is the appearance of organisms with a body divided into segments and − possibly even more crucial − of organisms in which, during development, after the segmentation of the embryo each segment gives rise to a different portion, anatomically, structurally and functionally different. Such as cephalic segments, with eyes, and antennas, thoracic segments, with legs, or wings, and so on to the tail − for those who have it. When each portion of the organism develops different functions, and must originate organs and structures with different organizations and functions, two kinds of problems arise. The first, which has fascinated and occupied scientists and has been clarified quite well in its general lines, is how such differences can be generated and perfected in a coordinated and organized way during the development of the embryo, which after all originates from a single cell which is not at all divided into segments. The second problem is how the different segments and the different organs can work in a concerted way so that each one gives its constructive contribution to the survival of the organism.

The development of an organism is a difficult but fascinating topic. The general mechanisms, variegated, multiple and sophisticated, can be related to a common and ingenious general scheme. To understand it is necessary to realize that a cell is a complex equilibrium; its structure is determined and its functioning are regulated by proteins. These are large molecules that perform structural support functions, thereby determining cell shape; control functions, thereby regulating all chemical reaction that occur in the cell (and in its numerous specialized organelles); and functions of transport and exchange across cell membranes, to maintain the different concentrations of electrolytes and biologically relevant molecules between the exterior and the interior of the cell (and of its organelles). The presence, quantity and localization of the various proteins in the cell − and in particular the differences between one cell type and another − make it possible for the diverse cells to display different shapes, structures, organizations and functions, and to interact in a different way among them and with the extra-cellular matrix.

Here is the trick! Though everything is written in DNA, the sublime library of recipes to build any protein that the cell may wish to produce, the question is to decide today’s menu. It is a vicious (virtuous?) circle, because who decides what to read in the DNA, which genes to turn on or off and which proteins to produce? it is always and anyway proteins, other proteins (transcription factors) or small substances whose production is again regulated be cellular proteins. Then, it is sufficient that a cell starts to produce a specific protein, that controls, by binding to specific sites in the DNA chain, the production of certain other proteins, some of them useful for specific cellular functions, some other capable of turning on or off the synthesis of other additional proteins...

Anything is sufficient: take a small molecule, for example, say retinoic acid, that is produced at a specific location in the cell, that is not exactly in the center. When the cell divides, one of the two daughter cells will have more retinoic acid, the other will have less. Mr. Retinoic regulates some genes, and the two cells will produce several proteins, and transcription factors, in different amounts; they grow up different, and may in turn generate daughter cells even more different, with diverse destinies. If an egg-cell is capable of generating an organism, it is not only because it possesses all the genes that permit producing all the proteins that are necessary for each cell in the organism, but also because a fine, complex and fascinating game links proteins and genes, that in a sophisticated minuet regulate each other and can generate complex and diverse figures and choreographies, furthering through divergent development pathways, apparently unpredictable and instead implicitly designed in the complex biochemical relations between DNA and proteins. Notice that once more we see a picture which has a higher degree of complexity than any DNA in isolation: a DNA a hundred times longer, containing a hundred times as much information, would not be able, by itself, to generate the degree of complexity that arises from this interplay between DNA and proteins.

In this picture, some proteins − the products of the so-called homeotic genes or “master” genes − are capable of orchestrating long term programs, and their differential expression in different regions of the embryo determines divergent fates for similar cells, which will generate different organs, or portions of the body − a wing rather than a leg or an antenna, for example − depending on their localization in the axis of the embryo.

In an organism that displays well differentiated body structures and organs, the problem of communication arises. If specific cells are capable of recognizing precise stimuli from the external environment, it is likely that the response of the organism requires the activation of other cells, presumably different, possibly positioned in a remote region of the body. For the cell that recognizes the stimulus it is possible to produce substances that, when released in the extracellular space − or in the blood, for organisms that have a heart and a circulatory system, − reach all the other cells, and therefore also those that are in charge of the correct response. This is the principle that underlies hormone production. On the other hand, it is much more efficient to be able to transfer the signals from one site to another in the organism, specifically and precisely, especially when the kinds and intensities of the stimuli that are to be distinguished grow, and similarly grows the variety, specificity and tuning of the possible responses; even better would it be to be able to add, compare, elaborate the signals before conducing them to the site where the response is to be generated.

This is the function of the nervous system. And the greater is the complexity and richness of the information the organism obtains from the environment, and the variety of the possible behavioral responses, the greater is the necessity of a centralized organization of the elaboration of signals, and thus of a central nervous system within which all information could be correctly put in relation.

Here we are. This is the classical, and clear, vision of neurophysiology: thousands of sensors, diverse and refined, a system of signal elaboration, capable of computing the most appropriate response possible by the organism to the momentary external reality, and systems that realize such response, by controlling internal vegetative and visceral activities as well as all elements in the organism that can produce movement, and therefore a behavioral response.

We got lost in following how, in this process, the elaborative elephantiasis of our brain furthers and goes astray in abstractions, among symbols, sentiments and existential wishes, instead of studying, like good scientists, how external reality, stimuli and their interpretation, determine our behavior.

Lets take care of this, then, straight ahead.

Warning: skip! hop! jump! here is another bunch of neurophysiology pills...

NEUROPHYSIOLOGY OF MOTOR CONTROL

Muscle movement is controlled by nervous cells (motor neurons) that are positioned in the anterior part of the spinal medulla, close to the point where the spinal nerve that reaches the muscle leaves the medulla.

Motor neurons receive a large number of synaptic signals that control their electrical activity and determine the frequency with which the motor neuron itself will discharge “spikes”, electrical impulses capable of propagating down to the nerve terminal, which releases a neurotransmitter (acetylcholine) when the impulse reaches it, thereby producing an electrical response in the muscular fiber and a twitch of contraction. Typically, to produce the contraction of a muscle, the group of motor neurons that innervate its fibers discharges spikes in a coordinated way so that the whole muscle smoothly contracts, by summating the twitches of the single fibers: the greater the number of motor neurons simultaneously active at any moment, and therefore the higher the frequency of discharge of the neurons, the stronger is the contraction of the muscle.

In the muscles there are groups of modified fibers which do not contribute much to contraction but host nervous sensory terminals that are activated by stretching the fiber itself. The sensory neurons that receive this signal − which informs on the length, and on changes in length, of the muscle − deliver it to neurons located in the posterior part of the medulla, which put this information in relation with similar data coming from other nearby muscles and send the results of such elaboration both to the local control network and to higher levels of the nervous system, where it will be integrated within a wider picture. But one process of the axon also directly reaches the motor neurons that innervate the muscle itself from which the information arrives: try and stretch a muscle and directly, through a simple reflex arch, the motor neurons are activated and shrink it back. Hit the tendon, just below the knee, this stretches a little the quadriceps muscle of the thigh (the large mass of muscle in the anterior part of the thigh) and the reflex arch produces a contraction of this same muscle and a forward movement of the leg. Trivial circuit. Little fascinating and little interesting as well, at first sight.

But let us think for a moment what this stupid circuit produces. I decide I want to put my leg in a certain position; because of a shock, a change in weight distribution, an involuntary contraction of another muscle, an acceleration of the bus, a change in pitch of the ship bridge, the position I wanted to maintain changes a little; a muscle gets stretched, the reflex arc stimulates it, it contracts and resumes the original length, the limb resumes its position. So, the circuit is not so stupid: though trivial, it is sufficient to help maintaining the position of a body segment without any need of continuously re-computing and modulating the degree of nervous stimulation that is needed to maintain the chosen position.

Generally speaking, and considering the need for much more complex and sophisticated circuits, a large part of the circuitry in the spinal medulla is organized according to these same criteria: networks of neurons that stabilize the position of body segments by comparing, computing and balancing the levels of activation of motor neurons; they help the contraction of a muscle by avoiding that muscles with an opposed action be simultaneously activated; they regulate positioning of muscles and joints so that comfortable or effective postures are assumed; they facilitate the coordinated, alternate and oscillating activations of opposing muscles that constitute the basic design of complex motor behavior such as perambulation (hey! here the most sophisticated one is not us: if it is complex for us to walk, just think what a mess must it be for a millipede...).

As you ascend the medulla you find more and more complex networks − and what are technically called central pattern generators − that coordinate and integrate complex but standardized motor behaviors. For example, in order to control posture, and simply stand still, you need all medullar circuitries up to the brainstem, where vestibular information, that comes from the inner ear, joins the central nervous system and tells it what is the position of the head − and indirectly of the body − with respect to the gravitational axis.

These axial circuitries sustain even complex reflex behaviors: if you suspend a newborn baby by holding his thorax with your hands, he will extend all four limbs in a “anti-gravitational” reflex; if you hold him with your hand under his shoulders, let his feet touch the table and slide him forward, he will coordinately move his leg as if he were walking; if you touch his cheek he will turn his head, open his mouth and start sucking − that works better if something to suck is there, but is not a sensible response governed by the happy realization that mum (a wonderful object with breasts) is there, it is simply a reflex activity. Some quite complex behaviors are therefore interpretable as pure reflex responses, sustained by pre-cabled circuitries in our lower nervous system.

Pre-cabled circuitries may also sustain pretty complex and sophisticated behaviors, that must involve higher, possibly cortical, structures. All these behaviors might be defined as “instinctive”, and together with reflex responses constitute a rich set of “innate” behaviors.

We have already discussed the role of cerebellum in controlling and assisting voluntary movements, and its great learning capability, such that after assisting for several times a specific sequence of movements the cerebellum becomes capable of realizing it all by itself, with no need for voluntary control or a conscious supervision of the movement: indeed, the movement becomes even more precise and markedly more rapid. This is the most important kind of procedural memory, and underlies the execution of all automatic behaviors.

Curiously enough, we tend to think of “spontaneous” movements, reactions and behaviors as something that is more strictly ours, inborn and personal; still, most of our “spontaneous” responses − rapid and not voluntarily controlled − are automatic rather than pre-cabled, and are therefore acquired by repetition and represent (who is going to accept this?) the result of conditioning.

Truly voluntary, intentional behavior is regulated by even higher centers, mostly the motor cortex. Notice that, with all the hierarchical organization of motor control we have discussed, an incredible number of reflexes, counter-movements and balancing reactions must be controlled, inhibited or modulated in order to execute any movement the cortex may wish to command. Thus, something in our head must keep track of all lower control system, and tell the cortex what muscular groups must be stimulated and what must be inhibited in order to execute even the simplest intentional movement without being contrasted by all reflex circuitries. This is the role of BASAL GANGLIA. They receive information on any motor command the cortex wishes to output and return to the cortex all necessary indications about which muscles must be facilitated and which ones inhibited to properly execute the desired movement.

Basal ganglia also receive input form pre-motor areas of the cortex, regions where movements are studied and prepared before execution; thus, they may modulate all commands from the motor cortex in such a way that future movements are also favored. This makes it possible to execute complex sequences of movements with great fluidity, to harmonize different motor tasks that have to be performed simultaneously, and to reconcile behavioral programs on different temporal scales. This explains why dysfunctions of the basal ganglia − such as are encountered in Parkinson’s disease − interfere so heavily with the initiation and the performance of motor tasks.

Once again, we might recall here the general observation that a circuitry capable of performing a specific cognitive elaboration will generally perform it on all material that is fed to it. Thus, the cerebellum is not used only for motor learning, but for any form of procedural learning, such as for example repeating multiplication table results, a poem or a prayer, or performing grammatical and syntactic checks on sentences while we speak, and any other purely automatic procedure in cognitive performance. Similarly, the basal ganglia not only help in harmonizing complex sequences of movements − and display a relevant learning capability in that respect − but also apply the same computational scheme to processing of visual, auditory and cognitive information; thus, thanks to the dialogue between the posterior part of the basal ganglia and the occipital (visual) cortex, an interrupted sequence of images can be filled in, in observing relevant scenes while awake (we can “see” a person while he walks behind a column) and in generating dreams while asleep, or hallucinations in the presence of psychiatric disorders or in response to administration of drugs.

We shall come back to this, but the most relevant aspect of all this story is that each stimulus may produce many different responses, from the simplest and fastest one (reflex) to the slowest and most complex one (intentional behavior), and any response which implies a more complex elaboration, in order to be executed needs that simpler responses be inhibited.

The question, in discussing human behavior with the aim of being scientific, is that science is required to maintain (and this is has been pretty wrong in the last fifty years, in my opinion) a purely deterministic approach: the nervous system is a machine made to produce appropriate responses to stimuli, so that the conditions of the organism are maintained stable − when everything is ok − and are brought back to balance − when something goes wrong. It is the “black box” idea: signals enter, something happens, a result comes out. Science’s job is to argue how the box works. The difficulties arise when drives, motivations, or goods among which one must choose are equivalent: in that case the intellect − taken as a black box − does not offer any indication, the will remains undecided, the choice does not occur and one ends up like Buridano’s donkey, who dies of starvation because he cannot CHOOSE between two equal and opposing stimuli.

Furthermore, something else intervenes in moving our behavior: desires are there, and ambitions, sentiments, emotions and values: what is all that? is it the spirit that somehow tickles the neurons? or anyway how do these abstract drives get translated into motivational forces, capable of moving the neuronal network?

At every moment a thousand forces, reflex, inborn, instinctive, apprehended, visceral, rational, affective, ethical, ideal, face each other in the brain to decide your acts, your words.

And the soul is measured by the result that this turmoil of opposing forces produces.

Each choice confirms, or negates, or retouches the equilibrium that you, your history, your past choices have established among the forces that guide your spirit.

Each choice retouches your soul. YOU retouch your soul, at every moment, by marking new − or partly, or not at all new − notches in the balances that guide your choices, and writing this way your life, your future.

A future that is written as a note, to be reread and reformulated − equal, almost such, or different − in a moment or a day, a month, a year; when you DECIDE to choose different balances, and you do so because of one or a thousand new experiences, and specially because of how you have lived them (have decided to live them).

NOTHING IS WRITTEN.

But what is not written is not CHANCE.

Sure, fate can push you, here or there.

But at any moment a slight gust decides, in the uproar of contrasting winds, your direction, and brings you elsewhere, where the game of the winds is different.

Your story may well be the game of these winds, but perhaps even more it is that slight gust, that beat of wings of a butterfly, that in any moment decides the future tornadoes of your life.

The wings, the butterfly, are not “chance”. No. It is the soul.

It is the soul, that gets formed and grows through details and nuances.

If a daimon is there, a guiding spirit that governs your choices and your needs, it is you who build it, a bit at a time, in every moment of your life.

The slight gust, the whishing of wings, are clearly perceived.

And similarly the still souls are perceived: you feel the stale air.

What an enthusiasm when you encounter untamed souls that can retouch, change, grow. That are able too BE.

Curious, attentive, multiple, mobile, alive.

You can feel the aroma, from the eyes, the gaze, the gestures, the emotion.

The idea of a computation, of behavior as an accounting balance, is unacceptable to whomever looks inside himself and finds something more than detached evaluations, because he does not renounce to passion, sentiments, angst, commitment, doubt, fear of blundering.

Actually, in that black box there is a multiplicity that is too often underestimated − “there are more things...”, how was that? ... yes, and there are more than we can dream of in our nervous system as well.

It is true that sensory stimuli can produce responses, But the essential fact is that they do more than that.

Each input to our nervous system influences the activity of thousands of neurons and in each of them it is combined and integrated with different data − each neuron and each neuronal system computes, elaborates and recognizes different elements and relations within a set of input that is partially coincident and partially is not so.

This is what computer people call parallel processing − a thousand systems which elaborate information in different ways, simultaneously, each of them with its own criteria, objectives and logics, each one concentrated on what it is interested in recognizing.

The stimuli do produce responses, then, but the responses are not computed by a machine: it is always an interplay among many possible responses, among many elaborations that concurrently proceed.

Let us analyze some adjectives that refer to behavior: reflex − instinctive − inborn − automatic − spontaneous − conscious − voluntary − intentional − rational − ethical.

REFLEX is almost inevitable: a neural circuit, they hit you below the knee, the muscle gets stretched, the nerve brings the signal to the medulla, the neuron that controls the muscle is activated, and you kick; only if you take care, and if you know it in advance, you can avoid it

INSTINCTIVE is more complex, but it still tastes neural circuits, reflexes, something already written there: hold a newborn baby by his thorax and he will extend arms and legs, as if he wished to attenuate the crash... hold him standing on a table and let him slide forward, he will move the legs as if he walked; it is complex behavior, such as sucking and swallowing as soon as you touch the corner of his mouth, but still it is something already predisposed in the nervous system. And it accounts for most animal behaviors.

INBORN may be less defined, it suggest individual differences, somebody may think of fates, destinies and daimones, in addition to genes and circuits... But certainly it has no flavor of free will.

AUTOMATIC, you can learn it. We begin to escape the domain of behaviors that are pre-written in neural circuits. It can be very complex, it even permits us to perform sophisticated and efficient behaviors in such a way that we could not reproduce intentionally... You can repeat a poem in an automatic fashion, play a very difficult piece at the piano, and you do it better if you do not think about it, otherwise you get stuck... Most of all, you can play the play-station automatically: never try and understand what you have to do, in a rational way, only learn to rapidly press the keys, and let your fingers do it.

SPONTANEOUS is somehow the sum of instinctive, inborn and automatic, partly already written and partly learned, complex but rapid, without thinking, unconscious, sometimes even unaware.

Well, it is interesting that here already genes and daimones have lost control: what we see and live as spontaneous, in most part is LEARNT rather than innate.

Then there is CONSCIOUS, looking at oneself acting, comparing different reaction schemes, recognizing what we are doing and what guides us.

And finally choice appears: VOLUNTARY (strictly speaking, INTENTIONAL, because physiologically any muscle that you may move voluntarily is said voluntary, even though it may move without our even noticing it, like respiratory muscles): intentional is no more being carried, it is acting, intervening.

At each of these steps new possibilities are added, and greater complexity, and growing multiplicity.

RATIONAL is all this, and attentive analysis and synthesis, in addition, and logics and harmony.

One thing is crucial, in this escalation: TIME. Reflex responses in milliseconds, more complex inborn circuits may need a few tens of milliseconds, demanding automatic responses a bit more. A voluntary act requires tenths of second − the structure and the complexity of the neuronal circuits demands these “long” times (on the timescale of neuronal activity) − and a rational response may ask for seconds, minutes sometimes, or a good sleeping night.

Finally, ETHICAL. If one watches closely, it only adds beauty. Harmony, capacity of reconciling different needs, considering reality, and the others, and love, good, right, just. Taking care of everything. And sometimes an entire life is not long enough, for an ethical choice.

And the more you ascend this staircase, the stronger you feel the flavor of soul.

Identity − me

Strange ambiguities and paradoxes. Sweet, bitter, tasty, spicy, acid, flavorless, insipid... The most efficacious “sensorial” adjectives, those that appear to grasp the essence of things and their emotional relevance, are gustative − the most visceral sense.

Sure. The part of the brain that elaborates emotions is strictly linked to the regions that control visceral functions; but is it there, then, the deepest part of us, is that the way to the soul?

Let us go back to behavior: it seems that what is spontaneous tells more about us as we really are, the most deep and true part of us. Baloney! It tells more about a part of us, the fastest and least complex, the most biological, least multiple, least beautiful part of us. Least beautiful, but not because it is ugly, simply because it is banal, trivial, ordinary, it does not scent multiplicity, complexity, freedom, it has no flavor of soul.

Flavor, scent, perfume. Sure, perfume: perfumed lily of the valley, and cold, beautiful and scentless orchids. Like people, one would say, some of them handsome, gorgeous but with no hidden treasures, others like timid, but scented rosemary.

Easy, maybe too easy, the parallel between perfume and soul. Nothing strange: the part of the brain that analyzes odors is among the first ones to develop, evolutionarily; almost all animals have an olfactory cortex more developed than ours. This is obvious: the nose lets you localize enemies, preys, food, fire, toxic substances, partners and their sexual accessibility. Lower animals, that swallow whatever moves, may do without much cortex, but differential identification of a smell is a complex question and requires sophisticated processing: this justifies the development of the archi/paleo-cortex, which is mostly organized about olfactory input. And this region of the cortex, the most antique one, is intertwined with the areas that elaborate visceral information and move emotional life.

Perhaps this is why what smells seems to talk to us more directly from deep inside. And more deeply marks our memories. Because that which moves that part of the brain, the ancestral, visceral, emotional one, leaves the most profound marks (should we mention Marcel's madeleinettes?).

Thus, perfume, visceral, emotional...

Damn! we look for the soul, what looks as the most true, deep, uncontaminated, ineffable part of ourselves, and we end up on the instinctive and visceral part, what is there of most biological, corporeal and fleshy in all that one could find in the sublime games of neurons, something much less spiritual than logical abstractions, reasoning, fantasies, dreams and desires, ideals, commitment and sensibility to beauty and right...

In the end, it appears that the deepest individuality, far from being pure spirit, be rooted and entangled in the strictest and deepest way with our viscerality, with our flesh, with our cells, nerves, with biology, with matter.

Still, who would not see all this as a part − a deep, indispensable part − of the soul?

So, we must change our perspective. The brain cannot be considered as a machine that generates responses and guides behaviors based on the stimuli the organism receives. One cannot even get close to understanding how the brain rules behavior without initially being surprised, astonished and enchanted in front of the richness and multiplicity of the facets of each activity of the nervous system, from simple perception of sounds, odors, images, to emotional and affective coloring of each experience, thought, word.

Let us talk about choices, then, and doubts, but true questions, serious doubts, say “to be or not to be?”... It is so evident that here one exits the domain of pure calculus, that science can explain. But it would be nice to try and show that science can say something on this as well.

Once more the question is that of multiplicity, and integrity. The choice becomes INDIVIDUAL when all components participate to it, cognition, emotion, affectivity, esthetics and ethics, and knowledge, memory, desires, affects, fantasies, dreams, passions, commitment... Under such condition the choice, and doubt, is our, individual, whether the instinct or the reason guides us. Such choice must consider the “world out there”, and that the answers may change, but the problem often is that choices and acts, once they have been made, cannot be canceled...

On the other hand, here is the essence of free will, that is born from the possibility of choosing based on a hundred distinct procedures of evaluation and motivation that are confronted and faced in the centers that guide acts, actions, behaviors, projects. No calculus holds here. It is a complex mechanism, the intersection of a thousand processes, and a simple nuance might lead to totally different choices and results. There is a scientific approach, that has been developed to face systems like this one; it is the mathematic of nonlinear systems, and the theory of CHAOS − which has nothing to do with disorder or chance. It is a powerful approach that makes it possible to describe, and partially understand, the behavior, to identify “attraction basins” (types of behavior into which the system tends to fall back) and crests, from which the system will tumble toward one or the other development, possibly totally opposite, for the slightest, imperceptible difference in any one of the internal or external parameters, like a ball placed on the blade of a razor.

This approach lets us describe, UNDERSTAND − if one likes overstatements − a chaotic system, but never PREDICT it. A thread, a nothing imprecisely measured, or neglected, and the system will change in an unpredicted way.

And for human behavior, this unpredictability tastes uniqueness. Individuality, freedom and creativity.

Thus, what is truly individual is the combination of all our ways of reacting, from the reflexes, and spontaneous and visceral responses, to all that we have learnt as automatic, to our rational and ethical evaluations. The doubt, the choice, the act, is then ours, INDIVIDUAL, whether the instinct is guiding us, or emotion or rationality. Many analyses and evaluations that consider different aspects with different gazes simultaneously move within the nervous system − it is a concurrent and tumultuous proceeding of independent elaborations, like in a badly governed assembly, or an evening among friends, where one starts talking, another one interrupts him and starts talking about something else...

The most interesting aspect is that this is exactly our way of elaborating, the way our brain works. It is so for memories, emotions, desires, it is so for thinking, reasoning, dreaming.

In response to each stimulus − be it external or internal (images, ideas, spoken words or simply thought of) − each system proposes its own associations − be they sensations, emotions, images of episodes of memory, evocations of other concepts, or of other words. And one ends up following a new, often unexpected pathway, exactly as the thought follows a thread as long as it can, but it finds itself displaced as soon as a word or an image produces a strong evocation, like a tourist who abandons the tour proposed by the guide, distracted by an unexpected sight.

Each brain is distracted / attracted by different perspectives... The primary cortex is rather invariable. In face of a trompe-l’oeil, of an optic illusion, we are all deceived in the same way, because we all elaborate the image in the same way, no one has a cortex more clever that the others. But when we consider the parts of the cortex that elaborate, when we reason on it, then each one reasons and interprets his own way. Because each one of us, in the pathway of thought, of evaluation and of choice, evokes different associations, images, memories, emotions, desires, stories.

This is why our choices cannot be predicted, there is no constraint, predestination, automatism, or trivial computation determined by genes and experience. Human choices cannot be predicted, the same way as the value a stock will have tomorrow cannot be predicted, even though the mechanisms that determine stock value fluctuations are perfectly clear, and even if no hazardous or unpredictable events occur (wars, or suggestions of prime ministers who have financial involvements to their friends...); because the stock exchange trends are the result of many many heads, each one with its own criterion.

Experts teach you that if you wish to take a decision in a rational way you have to fetch pen and paper, and write down advantages and disadvantages, possibly with scores, for the different hypotheses, and build a table that lets you see everything there, together. But why is this useful? trivial, because the brain does not do that: as the thought follows a thread, but any evocation can deviate and enrich it, in the same way we perform our evaluations: it seems we follow a thread, but it is a hundred threads, and now one aspect prevails, now the other does, now an emotions gives weight to a perspective and unbalances towards “pro”, now a memory brings back to other considerations...

It is not a hundred simultaneous evaluations, a hundred forces − motivations − that pull in favor or against, with a RESULT OF THE COMPUTATION that determines whether it is yes or not.

No. Each evaluation evolves in time, changes the intensity of its motivational force, and in addition the spotlight of attention illuminates one of them now, another one in the next moment.

We have seen that already in sensory cortex the neuronal circuitry is capable of collecting and analyzing, and then re-elaborating, comparing, following in time: an unconscious and complicated process of focus displacement, getting closer and stepping back, changing view angle and perspective. The same process occurs in multimodal regions, where different kinds of information are combined in search of assonances and dissonances, relationships with emotional impulses, with physiological needs and motivational drives. This exam, performed by focusing on each single piece of information, and then on combinations thereof, again and again with different sequences, narrates the experience bringing to the threshold of consciousness events, concepts, ideas, and the awareness of reality and of oneself.

Similar processes lie below the choice: there is a hierarchy of neuronal circuits, in which each system exploits all elaborations produced at any time by “less noble” systems, and extracts relevant aspects and coherent readings by cruising in this sea of elaborations. Each piece of information is attributed a specific relevance and each one must be put in relation and merged with the other similarly relevant bits of information, to yield at any moment the best “response”, or better the best “reading”.

But this is not calculus. Rather, the many analyses and evaluations that consider different aspects with different gazes, and simultaneously move within the nervous system, may push us to choose exactly now, and say YES, or wait just a little, and end up saying NO.

It is not a computation, once and for all. On the one side each evaluation yields a time varying result, on the other side the centers that control motivation now analyze and consider one, in a moment will focus on another. Innumerable distinct procedures of evaluation and motivation are concurrently generated, are alternated and compared, face each other in the nervous centers that guide gestures, actions, behaviors, projects. Thus, a single instant more is enough to let a new evaluation prevail, generally a more complex one, often a more valid one. Here is unpredictability of human behavior. Unpredictability of our choice even for ourselves. Yes, there are mathematics that are capable of describing processes like this, complex and mutable − the fascinating mathematics of chaos theory, − mathematics that can portray such systems, and define probabilities, edges, bifurcations and attraction basins, but cannot predict behavior. Because behavior can be totally different because of a single imperceptible, infinitesimal difference in whatever detail.

Still, if you precisely knew each single irrelevant detail....

No.

You cannot.

This is one of the most important cultural progresses of the twentieth century. Heisenberg’s principle of indeterminacy − or uncertainty principle − assures us that even in an apparently simple system such as an atom you cannot know where exactly is an electron in a particular instant, and the more precisely you get to know that, the less precisely will you be able to tell its momentary velocity. It is not a mere problem of accuracy of the available measurement instrumentation − maybe tomorrow we shall be able to... − no, each electron has a precise probability of being at each location in each moment, this can be computed, but its precise position cannot be known, better, cannot be defined.

This is certain. One of the few things we can rely on. The certainty of our uncertainty.

And if the position of a simple electron CANNOT BE EXACTLY DEFINED, the same principle should grant that there is no way of DEFINING (notice, it is not a problem of “knowing”) WITH INFINITE PRECISION all the drives and motivations that fight in a brain, and their strength, and the sequence with which they are evaluated, and which will be the exact moment of the decision and what will be the way each drive and motivation is considered and weighted at that precise moment.

When I was young, and catholic, the thing that used to irritate me most in the whole story was “Mysteries” (capital M). Actually, I am not disturbed at all by mysteries, the unknown, difficulties. No, the problem was that these “Mysteries” could not be understood. To be honest, the relativity theory is not easy, either. But those “Mysteries”, you COULD NOT understand them, it was FORBIDDEN. “Human mind cannot...” − they contradict logic, to say it flat. But this is absurd! Precisely: it is a MYSTERY, you believe it, faith, and that is all.

Deep in my heart, I have always wished I would be able to demolish at least one of these mysteries. Now, the MYSTERY OF FREE WILL looks as the right one to be clarified.

Actually, free will is a tricky subject per se, but what is so “mysterious” in it is not well apparent at first sight: you might need to be catholic to understand it.

The question (the “Mystery”) is:

a) you are free to act following your “free will”

a) God knows everything, and

c) though your body might be considered as the natural product of procreation by your parents, God CREATED your soul, thus

d) God obviously knows what you will do in any occasion

d) if He had wished you did something different He would have created your soul different

e) still, it is right that you be considered responsible, and rewarded or punished, for your acts, because they are the consequence of your FREE choices

f) the MYSTERY − what defies human logic − is how you can be responsible for how God made you, and how can God know what you will do if you can change your mind at any moment.

But we just said it is not possible to DEFINE WITH INFINITE PRECISION the motivational interplay and therefore to predict human choice, that is therefore intrinsically, constitutively unpredictable. God may well know everything, but it would be no use, even to Him, to know something that cannot be DEFINED.

So there is nothing to know. And you are FREE. And no MYSTERY there, whatsoever.

Here is one of my preferred aspects of the wonderful power of the uncertainty principle.

So it is not possible to precisely know all the details, and human choice is intrinsically unpredictable. Like a nonlinear, chaotic system. You may tell how it is likely to behave in this or that condition, but you will not be able to predict with any certainty. And it is not a question of chance. Choice is a “deterministic” process (cause → effect), though it is so complex that the outcome appears to be influenced, or even determined, by chance.

Choice is unpredictable. Genes and facts are not sufficient to predict it, and chance has nothing to do with it...

All this has the flavor of uniqueness, individuality, freedom, creativity.

“But if I...”, then is not a futile game, the impossible history that different choices would have produced. It is doubt, regret, remorse. It is a possible truth, another possible story, if a detail had not escaped our attention, if an imperceptible instant of delay had permitted more complex and slower neural circuits to add some other evaluation criteria before an important choice of ours.

What moves us? − the urge of need, desires, fears and dreams, and then projects and rationality... but rationality is multiple and demanding, complex and nitpicking, gray and never satisfied − like a naughty sea, sometimes stormy, unforeseen drafts and mutable winds − often we would wish to have somebody near us, perhaps not to tell us what to do, but at least to share the burden and responsibility − somebody who at least looked at us, held our hand, smiled to us, someone who did not leave us alone.

Three are then the axes along which the various levels of behavior move.

TIME:

• pre-written circuits respond in milliseconds;

• automatic behaviors are almost as rapid: if you try and construct your dance steps, the movements of your fingers on the piano, the words of a poem or prayer learnt by heart, you stagger and hesitate;

• voluntary acts require tenths of a second;

• rational choices at least seconds − better an overnight sleep

• for an ethical act an entire life may not be enough.

MULTIPLICITY: the more time you allow to your reaction, the more numerous approaches are confronted; instinct does not necessarily succumb, but it is no more the only factor. Multiplicity − each aspect per se but also with regard to all that to which it can be put in relation: rules and internal logics, yes, but looked at from outside as well, and in relation with any other possible logic. And analysis, and re-reading in a wider perspective − metanalysis − and higher systems always in search of unifying views, of HARMONIES, although momentary.

BEAUTY: even an automatic act can become perfect − under the athletic and formal aspects − but there is a kind of higher beauty in the ethical act, a beauty comprised of a synthesis of all aspects and dimensions: ethics, in the end, is nothing but being able to look at oneself, and choosing the most beautiful act, absolutely, capable of harmonies in many dimensions.

Here we find something to which neurobiology has not dedicated sufficient attention yet: circuits that are capable of triggering the most profound pleasure − as can be generated by a smile, an act of love − when an intuition, a new and unexpected perspective, an ensemble of sensations creates the harmony of a new fortunate synthesis of multiplicities: the pleasure of beauty... this is in neural circuits, and is there to be studied more carefully.

If all this is in the nervous system − and it is there − one cannot look at the brain as a input-output control system only, studied to optimize the response to incoming stimuli.

But − one would say − if the evaluations are performed by a computing system, complex as it may be, and if it is so awkward that it cannot evaluate everything together, but continues changing perspectives, if it is true that a moment of hesitation is sufficient to react in a different way... well, this way it seems it is simply chance, it is not ME who decides, it is only a flow of evaluations and who knows how, all of a sudden one of them wins and... zac! the choice is done. Where has all the poetry gone? and angst, and enthusiasm?

No, it is not chance. It will be exactly the way YOU have come to move among the different evaluations, the weight YOU attribute to their affective relevance, to self-assertive aspects, and fear and need for stability and protection, and to social, political, ideal aspects; it will be the way YOU have learnt to move around in this labyrinth, it will be YOUR TIMES; all this determines what your final choice will be. All this and not your genes. Not the experiences you have lived (the “ENVIRONMENT”). Rather, THE WAY YOU have lived them. How YOU − with the genes you happen to have, sure, and all the experiences you have gone through − how YOU have gradually modified, moment by moment, YOUR WAYS of elaborating, by modifying connections and circuitries among your neurons; how YOU have performed each of your choices, thereby progressively modifying YOUR WAY itself of performing your choices, and YOUR TIMES, YOUR criteria.

We now know many cellular processes that permit neurons to modify their connections and their way of elaborating the signals they exchange, in consequence of the information itself they are elaborating. Each experience changes the circuits that analyze it, the brain is modified by elaborating, the same way as the language evolves in speaking: each relation that is identified, each analogy and evocation, becomes a paradigm and a new perspective in future data elaboration, the same way as each word that is used in a different context assumes new color, meaning and evocative power. The circuits change, are modulated and continuously retouched in each of us, at each moment, and they are different today from how they were yesterday or they will be tomorrow.

So, much more than his genes, his interactions with the environment and his acts, each of us is THE WAY he has lived his experiences, has made his choices, the TIMES, the EQUILIBRIUMS, the HARMONIES according to which he has learnt to think and act.

Here, in this fluctuation among a thousand evaluations, is the origin of free will. This is the reason why our choices cannot be predicted, there is no constraint, predestination, automatism, trivial computation determined by genes and experience.

Not even our own choices we can predict...

The origin of all this is in that part of our brain that explores, cruises among evaluations motivations and possible choices, and unpredictably fluctuates, unpredictably but not randomly, guided by the finest details that we ourselves have built in our own brain in performing each act we have performed up to now, in interpreting each experience we have interpreted, in judging every event we have judged up to now.

That internal spotlight illuminates one or the other area capable of behavioral suggestions and motivational drives, in the attempt of following a logical path in reasoning as well as in performing an ethical choice.

The crucial characteristic of our choices is this fluctuation. Rarely do we gradually change our opinion, a little step at a time... Rather, we keep changing perspective. If in a precise moment one would command us to decide, exactly in that moment, we might decide in a certain way, but if they asked you to choose just 10 seconds afterwards, then your choice might have been well different; because the picture you are examining is different at any time, in each moment your attention is caught by different aspects, now it is more concerned with emotional aspects, then more turned toward rationality, or dreams, memories...

Here then, in this swinging among a thousand evaluations, in the way that each of us has developed, in his history, to navigate in this storm of opposed winds, here lies the origin of free will. This is why one cannot predict our choices, there is no constraint, or predestination, automatism, or trivial computation, determined by genes and experience.

It is free will, and simultaneously is the doom of remorse and regret.

Because in the end what really wears out is conflict...

In front of hard choices only this we might possibly ask, that the conflict ends − that the thousand forces that quiver in our soul agree, calm down, stop once and for all of redrawing lights and shades that change all the time, of generating doubts.

The dud for a whole generations of parents, exposed with no forewarning to dr. Spock’s revolutionary theories (Benjamin Spock, not the other one, with pointed ears − or maybe he had pointed ears, too, but nobody told us, or perhaps I am confusing names, his name was not even Spock...): you must understand and explain, the child must understand.

For many of us this has come to mean, simply, stop with NO’s, no more prohibitions, no more duties for these poor creatures.

Now, the problem is not whether they have grown up better or worse − sure, in general they are less respectful, they do not say “good morning sir”, “good evening madam”, they do not give way or cede their seat on the bus...

No, the problem is that with no prohibition and duties it is a terribly demanding task! for them!

I mean, give them a break! give a break to this child, give him some certainties! some rules based on authority, that freed him from conflict. Let him get angry at you, sometimes, instead of fighting within himself, between desires and rationality.

Not always, sure, let him too have something to mull over, some interior struggle to fight... But, at least once in a while, give him a break!

Vittorio Alfieri well knew how difficult it is to decide − every single moment − what to do, what is right. It used to be presented as a model, in Italian schools, a model of will − “volli, fortissimamente volli”, I wanted, extremely strongly wanted − and instead he was only able to oblige himself to study, tied to the chair otherwise he would not do it at all. If only Hamlet might have asked somebody to tie his sword to his hand, and guide it to perform the act that had to be performed! deciding once and for all, here, decided, I do it, and in that same moment − not an instant later, when a new doubt, uninvited, might have appeared − everything is done, finished, nothing more to say about it...

Because the soul is like the tide − now a few isolated rocks on the golden and warm sand, now only water, everywhere,

and now submerged and re-emerging rocks, and waves that stubbornly whip them and fall apart, and then come back again, as if they really thought they could change the world.

Nice would be, instead, to know that nothing will change, to decide now, here, and to know that somewhere else, tomorrow, the soul will be the same, every choice can only be confirmed, there will be nothing to regret or be sorry about. But in our soul at each moment a thousand drives, weak or strong, ask and cry, and face each other, now one seems to prevail, now another one...

Will, willing − it is not a choice − it is a storm, a chatter of requests and calls.

And will is not deciding, stating, holding on, screaming − it is persevering, insisting, resisting to circumstances, fatigue, doubts, desires − it is not setting a course, but being able to maintain it.

So, how you faced each choice, how you have learnt to face choices and changed your way of making them, what each of your choices has etched in you, in your neurons and connections in your brain, how you have lived each experience, each instant, each choice... This, all this indeed IS YOUR HISTORY − not what has happened to you but HOW you lived it, and how, as a consequence, you have been changing, moment by moment, and building your ego, yourself.

Perhaps, deeply in your heart, in that turmoil from which we fish out sensations and clear-cut, definitive judgments, that seem to have been deeply engraved there by someone else, before, forever, perhaps in there is clearly written how to recognize one’s own essence, the soul: there, where the possibility and capability of choice is, where the reading of the world is not fixed, the act is not only instinctual, where a behavior is possible that does not necessarily follows its own interest − and not only because of protective or species instinct, no, − where it is possible that behavior is guided by something else, by social, altruistic, ideal values, by forces that are not causes coming from the world of things, but motivations, aims, aspirations, dreams, passions that come from somewhere else, from what we have always loved to call the world of ideas.

An interesting aspect of all this is that in making choices we surely are not the best. Because when we finally decide, it generally happens that in the end we have overvalued some aspects and neglected some others. But when the question is to be able to consider higher values, and to compress some of our needs − possibly strong ones − in the name of something more important (higher harmony, beauty of the choice), then our “decision making” procedure, based on examining many subsystems of the problem under many different points of view, is the best one, and make us able of true ethical choices.

Still, in order to really consider most aspects, and to perform an ethical choice, one must remain in trouble for a while. And forget the hurry and the simple, easy and rapid ways...

A collateral but crucial aspect is that about half of our brain (the frontal part) is in charge of planning behavior, and its contribution to decisions consists in simulating and IMAGINATING the execution of the act, and predicting its consequences. This SUBJECTIVE rehearsing often contributes to delay, uncertainty, angst. Especially when we are faced by choices which imply unpleasant aspects on both arms.

Do you know of that test “if you push that button you kill 100 people, if you do not push it 300 will die”? most people honestly tell they would not have the courage to push the button... and the linguistic trick is perfectly correct, here, because when your forebrain simulates pushing the button, that precise act produces the death of 100 people, and you actually KILL them, whereas if you do not do anything your forebrain has nothing to simulate and the 300 WILL SIMPLY DIE. It is always easier not to do anything than rise up and intervene, it is always easier not to assume any responsibility...

Once more we find ourselves talking of extremely elevated aspects, ethical aspects, altruism, assuming responsibilities, aspects that go well beyond the dimension of our own personal life. We may not name the soul, but all this bring us in a social, ideal domain that departs from what one normally associates to brain and its functioning, to behavior in a neurological sense. But these things rumble precisely there, together with emotions, and memories, and dreams. It is curious, it often seems to us they bubble somewhere else, because the brain, if nobody tells us, we do not even realize it is there. Possibly, this is related to the intriguing aspect that the only part of our body which does not have any sensory receptors, for pain or anything else, is the brain. On the other hand, this may be obvious: what use could the brain do of receptors that tell it what is going on within the brain?

But this might be the explanation why it is so difficult for us to locate in a part of our body, or brain, all these emotional, affective, evocative, esthetic, social and ethic aspects, and we end up looking for a soul, somewhere outside the body, to accommodate them.