11 memetics in neurosurgery and neurosciencetheory has only been developed in the last few decades....

NeuroQuantology |June 2008 |Vol 6 |Issue 2|82-193 Di leva A. Memetics in neurosurgery and neuroscience

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Opinion and Perspectives

Memetics in Neurosurgery and Neuroscience

Antonio Di Ieva

Abstract Imitation is a powerful means of spreading culture teaching people to speak languages, children to play, and surgeons to operate. The basic unit of imitation is a replicator called meme which, like genes, carries and spreads information. The concepts of memes and the science of memetics were introduced by biologist Richard Dawkins in 1976. Since then, memes have been found everywhere, used to explain both social and scientific phenomena. Memes are ideas, tunes, fashions, and ways of saying things; they are also surgical techniques, because also these ones have the replicating power to jump from brain to brain via a process of imitation. Like general surgery, neurosurgery is a complex set of memes: neuroscientific concepts and surgical techniques shared by neuroscientists and neurosurgeons by means of congresses, articles and the imitation of others’ actions in operating theatres. The spread of neural memes is guaranteed by bridges interconnecting individual elements of general network, in the same way as fashions or infections do. Over the last few decades, neurophysiological discoveries, such as mirror neurons, have revealed the presence of a neural network that is very important in the process of imitation; studying memetics should be considered as important as studying genetics because both of them involve selfish replicators (memes and genes) whose co-evolution is fundamental in understanding the evolution of mankind and culture. The study of memetics and its applications in the fields of neurosurgery and neuroscience can offer a new perspective for understanding the mechanisms of both neural and social networks, thus providing a holistic view of neuroscience and social sciences that will lead to further insights into the science of the mind. Key Words: memetics, neurosurgery, neuroscience, genes, memes

NeuroQuantology 2008; 2:182-193

Once theories exist, they begin to have a life of their own.

Popper and Eccles (1977)

Introduction1 Large part of mankind’s cultural and intellectual growth is based on imitation. People learn to speak by imitating their parents’ and relatives‘ language; children learn to play by imitating each other;

Corresponding author: Antonio Di Ieva, M.D. Address: Department of Neurosurgery, Istituto Clinico Humanitas IRCCS, Via Manzoni, 56, 20089 Rozzano (Milan) – Italy

Phone: + 0039-2-8224.4617 e-mail: [email protected]

musicians learn to play by studying and imitating their teachers; and surgeons generally learn to operate by imitating older surgeons. The process of imitation gives reason to both vertical and horizontal transmission of information. Besides, something similar occurs in the animal kingdom: monkeys imitate each others’ gestures, and the cubs of each species imitate their parents’ actions.

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Imitation is also a powerful means of spreading culture: a “rare ability that is fundamentally linked to characteristically human forms of intelligence, in particular to language, culture, and the ability to understand other minds” (Hurley, 2005), an evolutionary factor by which individuals learn from society (Baldwin’s concept of “social heredity”) (Baldwin, 1896).

But although this concept has been recognised for centuries, an underlying theory has only been developed in the last few decades. One key to this new theory was the idea of a “replicator”: i.e. a meme which carries information and spreads it among people in the same way as a gene does. The word was coined in 1976 by biologist Richard Dawkins, who created the new theory of memetics, about the study of memes and how they spread and replicate (Dawkins, 1976).

After the publication of “The Selfish Gene” in which the theory was presented, the new theory rapidly gained ground, and memes were found everywhere: in arts and sciences; in languages, music, television, politics and culture in general; and in the forms of phrases, songs, pictures, and urban myths. But, strangely enough, it has never been applied to what must be considered a “replication-imitation” science/art par excellence: surgery (and neurosurgery).

In order to explain the presence of memes in the field of neurosurgery, it is important to review some basic concepts concerning memetics. Memes and memetics In 1976, Richard Dawkins coined the new word meme (pronounced “mi:m”) as he was looking for a word similar to “gene”. In his book “The Selfish Gene”, he wrote, “We need a name for the new replicator, a noun that conveys the idea of a unit of cultural transmission, or a unit of imitation. Mimeme comes from a suitable Greek root, but I want a monosyllable that sounds a bit like “gene”. I hope my classicist friends will forgive me if I abbreviate mimeme to meme” (Dawkins, 1976).

Therefore, the first definition of meme was a simple unit of information that

could be spread by process of imitation. Dawkins found that, like genes, memes have replicating power, “because they can jump from brain to brain via a process which, in the broad sense, can be called imitation” (Dawkins, 1976). Genes and memes are both selfish in the sense that they only exist in order to spread themselves.

After the biological definition of meme as a basic unit of cultural transmission, other interpretations and meanings arose. The psychological definition says that a meme is the unit of cultural heredity seen as the internal representation of knowledge (Plotkin, 1993) or instructions for carrying out behaviours stored in brains or other objects and passed on by imitation. A cognitive definition says that it is the kind of complex idea which becomes a distinct memorable unit capable of spreading itself by means of vehicles which are physical manifestations of memes (Dennett, 1991), such as languages, books, articles, actions, and so on, living in computers, books, and minds (Dawkins, 1986). And if we consider the brain as a meme-keeper, another definition is “the unit of information in a mind whose existence influences events such that more copies of itself get created in other minds” (Brodie, 1996).

In each of these definitions, a meme is a “bit”: i.e. a unit bearing information from one vehicle to another one. As Dawkins wrote: “Examples of memes are tunes, ideas, catch-phrases, clothes fashions, and ways of making pots or building arches. Just as genes propagate themselves in the gene pool by leaping from body to body via sperm or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation. If a scientist hears or reads about a good idea, he passes it on to his colleagues and students. He mentions it in his articles and lectures. If the idea catches on, it can be said it propagates, spreading from brain to brain” (Dawkins, 1976).

A similar concept was proposed by Lumsden when he introduced the “culturgen” as “the basic unit of inheritance in cultural evolution” (Lumsden, 1981). However, the word “meme” was a more powerful meme,



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capable of spreading faster and in a more capillary manner. It led to the study of memetics as the “scientific model studying how memes interact, replicate and evolve” (Brodie, 1996). Many new words in memetic lexicon were coined: meme pool, memotype,

memeticist, memeoid (or memoid), retromeme, population memetics, meme complex, memetic engineering, metameme, co-meme or symmeme, etc. (for information on the web-site of the Journal of Memetics: http://www.jom-emit.org).

Figure 1. The Tower of Babel, 1563, Pieter Bruegel the Elder (1525/1530-1569), Kunsthistorisches Museum Wien, Vienna (1992/1047), oil on oak panel. The painting describes the Old Testament event in which God punished mankind for their pride in creating different languages, so that men could no longer understand each other or finish building the tower. It is a metaphor of incommunicability. As language is one of the most powerful means of spreading ideas, the creation of different languages was a great punishment for memes because it limited their diffusion. Where memes live and how they spread Memes can be found everywhere. They can be stored in brains, computers (hard disks, CDs, DVDs), books, pictures, catch-phrases, and Internet; they live in languages and music, in each concepts and actions.

A joke can be a meme; a slogan is a meme (e.g. “publish or perish”); a musical motif can be a meme, spread from a CD to a person or from one person to another one (think about the “Ode to Joy” by Ludwig van Beethoven). Dennett makes the example of the first four notes of Beethoven’s Fifth Symphony, memes replicating themselves and capable of reminding us the whole symphony (what he calls “a phenotypic

effect”, where, detached from the rest of the symphony, memes keep intact an identity of effect) (Dennett, 1995).

Memes spread by jumping from one person to another one, particularly by means of language: “Human language (…) is the main way of cultural transmission, which creates the infosphere in which cultural evolution occurs” (Dennett, 1995).

They can jump in offsprings in form of traditions, ways of life, jobs, and habits. “There is at least a superficial analogy to the longitudinal transmission of genes down generations and the horizontal transmission of genes in viruses (…) which might play the role of gene in the transmission of words,



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ideas, faiths, mannerisms, and fashions” (Dawkins, 1999). Memes can therefore be passed from parents to children by a kind of vertical transmission, or by means of horizontal transmission. This theory was developed by geneticists Luigi Cavalli-Sforza and Marcus Feldman in 1981, with their detailed model of cultural transmission based on the “cultural trait” as the unit, learned by imprinting, conditioning, observation, imitation, or direct teaching (Cavalli-Sforza, 1981). As Susan Blackmore noted, their concept of “cultural fitness” as the survival of a cultural trait can be applied to the concept of meme (Blackmore, 1999). There are powerful and less powerful memes: some information survives for centuries and spread horizontally very fast, whereas other information dies (lost books, ideas falling on stony ground, lost idioms, etc.).

Figure 2 (a, b). There are some universal languages, such as mathematics and music, in which memes can spread easily and quickly. Two examples are Albert Einstein’s best-known equation of E=mc2 (Fig. 2a), or a musical score (Fig. 2b) that can be read by all musicians throughout the world at all times (the pictured score is the Introitus of Wolfang Amedeus Mozart’s Requiem in D minor, K626, composed in 1791).

Language is certainly the best way of

spreading memes, but the creation of different languages was an obstacle to this diffusion. The biblical story of the Tower of Babel talks about one of the worst punishments for memes: the creation of

different languages which limited their spread (Fig. 1). When only one language exists, memes spread more strongly and rapidly as, for example, in the worlds of mathematics or music (Fig. 2).

One very powerful system for storing and spreading memes is the World Wide Web, which was introduced in 1989; like television and language, it has become a special way in which memes can rapidly “infect” mankind by jumping from brain to brain.

Figure 3. According to Brodie (see text), viruses can be found in three different universes: the universe of biology (organisms, people, plants and animals); the “man-made” universe (computers, networks, data, etc.); and the universe of the mind (culture, thought, etc.).

Dawkins coined the term “viruses of the mind” in 1993 (Dawkins, 1993): the comparison of a meme to a virus is very powerful. Brodie said viruses can be found in three different universes (Fig. 3): the universe of biology (organisms, people, plants, and animals), the “man-made” universe of computers, networks, data, etc.; and the universe of the mind (culture, thought, etc) (Brodie, 1996). He wrote: “Viruses of the mind have been with us throughout history, but they are constantly evolving and changing. They are infectious pieces of our culture spreading rapidly throughout a population, altering people’s thoughts and lives in their wake. (…) Viruses of the mind, and the whole science of memetics, represent a major paradigm shift in the science of mind. (….) Once created, a virus of



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mind gains a life independent of its creator and evolves quickly to infect as many people as possible” (Brodie, 1996).

Ideas are infectious, and this infection works by means of memes. However, viruses need vehicles and, in his book, Dawkins distinguished “replicators” and “vehicles” by means of which they interact with the environment (Dawkins, 1976) (this explains why Hull called vehicles “interactors”) (Hull, 1988). People interact and “infect” each other by means of ideas, sayings, and so on, spreading the information of a selfish unit whose only purpose is to assure its spread.

On the basis of information and network theories (see the book “Nexus” by Mark Buchanan for more detailed information) (Buchanan, 2002), it can be said memes circulate inside small communities by means of strong ties and between communities by means of weak ties; as in the Internet and other (social, economic, etc.) networks, the connectors among sub-systems are called “hubs” (Fig. 4). In relation to the theory of weak and strong ties (Granovetter, 1973), the social bridges between hubs are very important for circulating memes, while weak ties are more important than strong ties because the first ones are capable of unifying the whole web and keeping it together. Hubs and bridges always have a critical point at which “memetic infections” die, become self-limiting, or spread throughout the network (Fig. 5) (a personal extension of the two-dimensional statistical growth process theory introduced by Eden in 1961) (Eden, 1961).

Just as genes take part in the genome, memes live in a web consisting of interactive and changeable connections of hubs, bridges, ties, vehicles, and guests: “no meme is an island” (Dennett, 1995). In this kind of interactive network, culture can be seen as a kind of self-organising (Ianneo, 2005) or “autopoietic” system in which some basic laws guarantee the self-maintenance of the same network (see “Autopoiesis and Cognition. The realization of the Living” by H.R. Maturana and F.J. Varela) (Maturana, 1980).

Like genes, memes are selfish and their sole interest is to replicate themselves

as often as possible by jumping between bridges and hubs in order to infect more units in the web. It is irrelevant if the units are brains, computer hard-disks, sheets of paper, or songs: everything is a vehicle or store, a part of the memosphere. This concept is reminiscent of the phrase: “Mankind is a catalysing enzyme for the transition from a carbon-based to a silicon-based intelligence” (Bricogne, 1991), Computers and artificial intelligences are also meme vehicles and keepers.

As memes have the same characteristics as viruses (they penetrate, copy, possibly issue instructions, and spread) (Brodie, 1996), they are capable of “infecting” brains by replicating themselves and spreading through space and time. Every item of news or information can jump from one vehicle to another one more or less rapidly and more or less effectively, infecting people and whole communities, their way of thinking and sometimes their way of being. But, in addition to viruses, memes are also metaphorically seen as parasites of their “vehicles”, sometimes providing a symbiotic benefit, sometimes damaging them (e.g. the “suicide memes” in some holy rollers).

But, although the best metaphors for describing memes may be genes, viruses or parasites, the absence of any DNA-like system of replication suggests that they may also be appropriately compared with prions insofar as they just need a matrix onto which they “impress” their information. Anatomy of memes If a meme is a bit of information, more simple elements can organise themselves (or be organised) into what Dawkin’s called “co-adapted meme complexes” (Dawkins, 1982), and Speel re-christened memeplexes (Speel, 1995). Religions and cults are memeplexes and, in 1993, Dawkins coined his term “viruses of the mind” precisely in order to describe how such memeplexes can spread through many people and have disastrous consequences for the infected ones (Dawkins, 1993). Susan Blackmore suggested that aliens are memeplexes of the stereotypes that most people have in mind when they speak about extra-terrestrial forms of life (Blackmore,



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1999). Human consciousness is a huge complex of memes (Dennett, 1991; Dennett, 1995), because the self is a vast memeplex Blackmore calls selfplex (Blackmore, 1999).

Every discipline is a memeplex consisting of more or less different memes. Hierarchically, three notes of a symphony can be a meme and the whole symphony a

memeplex, but the author’s music as a whole is a more complex memeplex, and so on. In the same way, medicine is a huge memeplex made up of smaller memeplexes representing specialist fields, which consist of meme units of information.

Figure 4. Web diagram elaborated in 1973 by Granovetter (see text) describing the concept of weak and strong ties, here revised to explain the spreading of memes. In “small worlds” (small communities, families, hospitals, and so on), memes can spread very quickly by means of strong ties, but the spread of memes throughout the network is guaranteed by the weak ties linking the individual elements of the sub-systems. In this diagram, 14 units (i.e. neurosurgeons) form part of four communities (hospitals): A (made up of elements 1, 2, 3), B (4, 5, 6, 7), C (8, 9, 10), and D (11, 12, 13, 14). The continuous black lines show the strong ties along which memes flow within each small community, and the broken lines the weak ties along which memes flow and spread among the communities. Elements 2, 3, 4, 6, 8, 10, 11 and 12 are the system hubs, which are very important for the circulation of memes throughout the web, or the social bridges capable of uniting the whole network.

“All concepts are composed of

memes” (Brodie, 1996) and, as concepts are organised into theories which form cultures, theories and cultures are memeplexes.

Therefore the anatomy of memes is a system that can be considered rather like a set of Russian matrioshka nesting dolls: each set of memes contains sub-sets, and so on towards infinity. Memes versus genes The words memes and genes are closed-sound monosyllables (as Dawkins wanted), and both of them are “selfish”. Both are also replicators, but “they differ in how they work,

how they are copied, and the timescales in which they operate. (…) There is also an important asymmetry between them: memes can operate only by using brains created by genes, whereas genes can (and do) operate perfectly without memes” (Blackmore, 1999).

Memes and genes can spread vertically among offspring, and horizontally as viruses and news do. However, although both of them can generate mutations (and the errors in both of them can be repaired), genes are more “high-fidelity” replicators than memes (Dawkins, 1999). Memes and genes can evolve, but the acquired characteristics are not passed on to offspring



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in genetics, whereas this can happen in memetics, explaining why memetic evolution is “Lamarckian” (Blackmore, 1999; Dennett, 1995). Furthermore, memetic evolution is many orders of magnitude faster than genetic evolution (Dennett, 1995).

Figure 5. .Diagram of the contact process of two-dimensional statistical growth by which memes can spread like infectious diseases. Considering community hubs and bridges in the network terms of weak and strong ties, a meme can reach a critical point of diffusion that allows it to spread throughout the web as a sort of “memetic infection” in the same way as a fashion or virus infection. Congresses and journals (particularly electronic journals) are the best hubs in the neurosurgical community for spreading and sharing the memes of ideas and techniques.

Like genes, memes are potentially

immortal, and both of them depend of the existence of a continuous chain of physical vehicles: i.e. the immortality of genetic or memetic information depends more on replication than on the longevity of individual vehicles (Dennett, 1995). Memes are controlled by a Darwinian selection and, exactly like the natural selection described by Charles Darwin, some memes are more “successful” than other ones and “fitter” to survive. They can spread more strongly and more rapidly (Dawkins, 1976).

Both genes and memes are subject to evolutionary processes of replication, casual variations (mutations), and undriven selection. However, genes need proteins and substrates to replicate themselves in helices and correct any errors, whereas memes may need only a tabula where they impress their information. They do not always need to be repaired when errors occur.

As Dawkins (and later Dennett) noted, genes as well as memes can be co-

transmitted, and some are often associated with others (“linked loci memi”) (Dennett, 1995). Examples of linked-memi are marriages and the Leitmotiv of the Third Act of Lohengrin by Richard Wagner, two memes that are very often associated (a song and an event).

Finally, genes are capable of instructing protein synthesis, while memes can modify behaviour (Delius, 1991). However, memes and genes should not be considered “competing” replicators because they have various degrees of interdependence, which has led to the postulation of a kind of “meme-gene co-evolution” in which effects of new replicators (memes) are seen on the evolution of pre-existing replicators (genes) (Bull, 2000). Like genes and the environment, memes contribute to build phenotypes (Fig. 6).

Figure 6. Old dogma stated that phenotypes are due to the effect of the environment on the genome; memes must now be considered as joining the genes and environment in contributing to phenotypes.

The power of memetics Memetics is the science of memes. Memes are everywhere. Memetics is applicable and reproducible in every time and place, and can be applied to cultural fields: sciences, economics, mathematics, philosophy, music, epistemology, and so on, in a kind of cross-over between social and natural sciences. As Brodie wrote, a meme is a secret codex of human behaviour, a kind of Rosetta stone for understanding politics, psychology, religions, and all products of cultural evolution (Brodie, 1996). Memetics can therefore be seen as a kind of “unifying theory” in which all cultural field converges: maybe “the long-awaited scientific theory unifying biology, psychology, and cognitive science” (Brodie, 1996), or “the grand new unifying theory we need to understand human nature” (Blackmore, 1999).

Moreover, in evolution theory (Darwin’s evolution of the species, Dennett’s



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universal Darwinism, Edelman’s neural Darwinism, genetic evolution, etc.), memetics replies to questions concerning the evolution of culture.

However, memetics is not such well-known or widespread theory as genetics, maybe because (as suggested by Dawkins) “memes have not yet found their Watson and Crick, they even lack their Mendel” (Dawkins, 1999). More time and further confirmation are required for the capillary diffusion of a scientific model of memetics. The study of imitation can also be applied to neuroscientific matters in neuromemetics field. Neuromemetics Memes and neuroscience As viruses of the mind or bits of information, memes live in the brain (Dawkins, 1982), which is their source and main storage location. Language is one of the most powerful means by which memes spread. Human mind is a kind of tabula rasa (Latin: scraped tablet or clean slate) which memes can be impressed on.

The human brain is a product of genetic evolution, but genetic evolution may have been driven by memetic evolution insofar as “memes could transform the operating system or computational architecture of a human brain” (Dennett, 1995).

If memes live in the brain, this means that they are “constellations of activated and non-activated synapses within neural memory networks” or “arrays of modified synapses” (Delius, 1989; Delius, 1991).

Genes can programme the brain’s architecture by means of protein synthesis, but “meme replication, is invariably associated with the induction of protein synthesis by involving neurostructural modifications” (Delius, 1991).

As language is the most powerful means of spreading memes, memetic evolution may have accelerated the genetic modification of the brain architecture by increasing the size of the cortical structures involved in language, and consequently the size of the frontal lobe: “human language capacity has been meme-driven, and the

function of language is spreading memes” (Blackmore, 1999).

If it is true that “human creativity is a process of variation and recombination” (Dennett, 1995), memes and genes varied, recombined and responded together in order to develop increasingly complex brain structures.

As theorised by psychologist Susan Blackmore, verbal language was a consequence of memetic selection and the large human brain was a product of meme/gene co-evolution: “in a few million years, not only the memes changed out of all recognition, but the genes have been forced into creating brains capable of spreading them – big brains” (Blackmore, 1999). Memes are seen as “intelligence enhancers” (Blackmore, 1999), and each form of meme (e.g. the memes in art) promotes human evolution (Dennett, 1990).

However, as even large brains have limited space, and as human mind has a limited capacity of storing memes, there is a considerable competition among memes to enter as many minds as possible (Dennett, 1995).

Memes are concepts, ideas, and brain information stored in specific synaptic structures and configurations: “Any cultural trait taken over by a given individual from another one must accordingly be thought as the transfer of a particular pattern of activated/inactivated synapses from the associative networks of one brain to another one. Different traits must be considered as being coded by topologically different synaptic patterns, that is, a given cultural trait borne by an individual is encoded informationally as a particular configuration of modified synapses in his or her brain. Naturally, the synaptic constellation a trait has in one brain will not be geometrically arranged exactly in the same way as the pattern that the same trait has in another brain: the brains of different individuals are likely to be too different. However, from a functional point of view, the two patterns could be still equivalent when effectively identical traits were represented in memory” (Delius, 1991).



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The problem of consciousness was not solved by Nobel Prize winner Francis Crick who said: “you are nothing but a pack of neurons” (Crick, 1994), because human consciousness and human brains are also made of memes (Blackmore, 1999).

On the basis of the recent discovery of “mirror neurons” in macaques (neurons that seem to be involved in a neural circuit capable of giving reason to imitations of actions) (Gallese, 1996; Rizzolatti, 2004; Umilta, 2001) and the fact that such circuits have been identified in the inferior frontal cortex (Iacoboni, 1999) and rostral part of the inferior parietal lobule of humns (Chaminade, 2005; Decety, 2002), it is clear that neurophysiological networks and mechanisms of imitation exist in the human brain (Iacoboni, 2005). This means that the storage and spread of memes have a neuroanatomic substrate. However, further studies are required to correlate mirror neurons and memes.

Neurosciences make up a memeplex full of memes concerning the physiology and anatomy of the brain, which is also the source of the memes itself: this amazing concept is reminiscent of a circle or one of Escher’s drawings (Fig. 7).

Figure 7. Drawing Hands, 1948, litograph, M.C. Escher (1898-1972). Which of the two hands is painting the other? Who is the author and what is the subject? This paradox is reminiscent of a circle, like the problem of the brain and the mind: the mind tries to understand itself, the brain studies brains. Neurosciences consist of memes: memes about brain physiology and anatomy, while the brain is the source and the keeper of memes.

Memetics in Neurosurgery In general, surgeons and neurosurgeons study surgical techniques by reading books, but they learn to operate by imitating older surgeons (residents, more experienced colleagues, etc.). Learning to operate takes place by means of a kind of “osmotic process” in which each gesture is stored in the brain and then imitated. When a surgeon creates a “school”, the surgical style of the pupils is characterised by similar techniques and sometimes even similar gestures: i.e. the style of Maestro has created some memes that have spread horizontally to contemporary surgeons and vertically to subsequent generations. Each individual surgical technique is a meme, as well as each surgical habit; the set of memes creates a memeplex of surgical ways of operating.

The whole field of neurosurgery is a memeplex consisting of other sets of memeplexes and memes. It is not important for memes whether they are right or wrong, good or bad; the only important thing for them is to spread. Operating on a pituitary adenoma using the transsphenoidal approach is a memeplex made up of the memes indicating how to do it, but so the transcranial approach.

In the case of transsphenoidal surgery, one “subhierarchical” memeplex is the microscopic approach and another one is the endoscopic approach. There are different schools and different opinions concerning the two methods, but memes are only interested in spreading, according to the “fashion” of the time. Each technique is a meme, capable of spreading from surgeon to surgeon, from country to country, from the Head of Department to an assistant, from Chief Residents to younger colleagues, from generation to generation.

One excellent example of a neurosurgical meme is the pterional-transylvian approach known by all neurosurgeons around the world. It was first proposed by Yasargil et al. in the 1970s (Krayenbuhl, 1972; Yasargil, 1977; Yasargil, 1976), who defined the technique by operating on patients and describing it on books, articles, congresses and “hands-on” courses. Most neurosurgeons learnt it by



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studying these articles and books and imitating other neurosurgeons; the luckiest one could directly imitate its father. In this way, the “pterional meme” has spread throughout the world over the last 30 years, becoming the most widely used approach for many intracranial diseases (brain tumors or aneurysms).

Although it was a good and powerful replicator, the pterional meme also mutated and some more or less important changes appeared at each passage. In the best cases, the “mutations” were the product of memetic engineering: i.e. modifications developed for different approaches (orbitozygomatic, supraorbital and subfrontal, subtemporal extension, combined approaches, etc.); in other cases, neurosurgeons imitated increasingly mutated versions until perhaps the approach could not longer be recognised by Yasargil himself. However, now it is not important to discuss whether the modifications are good or bad mutations, but to point out that every hands-on cadaver course, every paper, and every neurosurgeon performing the technique spreads the “pterional” meme further.

Residents store in their brains what they read, or see in the operating theatre or autopsy room, and replicate the meme or, using the memetic lexicon, the original pterional approach is the matrix from which each neurosurgeon imitates and reproduces the technique. Every neurosurgical concept or technique is a meme acquired from previous neurosurgeons or contemporary colleagues and, going back in time, we can say that the father of many of the current neurosurgical memes was Harvey Cushing, the founder of modern neurosurgery, the originator of the neurosurgical memeplex, and the Adam of the neurosurgical memosphere (Fig. 8).

As in the case of every memetic evolution, some of Cushing’s memes still survive, other memes have evolved by mutations, and others ones have died owing to various reasons. Like all fields of culture, neurosurgery is full of memes which have infiltrated the community as viruses or parasites, replicating every time from person to person. Throughout the world, you can

hear neurosurgeons talking about the frontal lobe of the non-dominant (generally right) hemisphere as the “silent lobe” of brain; there is no strong scientific evidence to support such an assertion, but what a good (and sometimes useful) meme!

Figure 8. Harvey Cushing (1869-1939), the founder of neurosurgery and the father of the most part of neurosurgical memes, “mirroring” his memes to the next generations of neuroscientists and neurosurgeons. Predicting the network and memetic theories, he wrote: "… keep up your friendships - form societies where you can meet together frequently to exchange ideas …". There is no doubt he was talking about the exchange of memes.

Ideas, concepts, and techniques of

the neurosurgical community (in a word, its memes) circulate around the world by means of papers, congresses, Internet, and so on. Like other scientists, neurosurgeons are “cognitive organisms” (as Shrader defines scientists) interacting culturally in the same way as all biological organisms interact with each other. “Small scientific communities collaborating on joint research projects may isolate themselves thus become akin to closed biological populations. However many communities are not small or closed. Essentially a scientific community is any group or network of scientists sharing their research results. Of course, in larger communities not all scientists share directly with all the other members of the community (many of the communication relations may be indirect or unilateral) (Shrader, 1980).

The most powerful means of spreading neurosurgical memes are journals,



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particularly those ones published online. The World Wide Web (e.g. PubMed) has accelerated the spread of medical research memes.

Every neurosurgical “school”, hospital or small community circulates the same memes by means of strong ties (e.g. between the Head of Department and residents), but weak ties interconnect every community in the neurosurgical network. Each surgeon moving from one community to another one imports and exports habits, ideas, and techniques (in one word, memes!), thus becoming a hub capable of solidifying the network in which information circulate. By means of weak ties in a network full of hubs, memes can spread strongly and quickly, avoiding the marginalization of small communities.

Both electronic and not electronic journals are the best means of spreading neurosurgical memes rapidly, but the post-graduate schools of specialisation are the first gymnasium for neurosurgical training, where residents learn and imitate the basics of the discipline. To paraphrase one of Dennet’s slogans, a residency is just a library’s way of

making another library – that is, why residencies in neurosurgery should be the best-controlled and organised way of spreading the right memes to younger neurosurgeons: medical doctors working in an amazing universe in which neurosciences and surgery meet, while brains cure (or try to cure) other brains.

The links between hospitals or neurosurgical schools and journals or the virtual scientific community are the congresses and courses where people meet to spread (hopefully good) memes, where the complex memeplex of the neurosurgical universe evolves as a result of the spread and mutation of memes, where their brainstorms can offer more solutions to the best treatment of pathologies and patients.

Good communication in neuroscientific and neurosurgical community is fundamental for spreading right memes: the future is not the Tower of Babel. Acknowledgments I would like to thank Carlo Russo and Fabio Grizzi for the second reading of the article and the opportunity of sharing every day memes with them.



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11 memetics in neurosurgery and neurosciencetheory has only been developed in the last few decades....

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