Dogs, language and laterality

The linguistic lateralization of our dog buddies spotlights a theoretical mystery

Many news outfits have published stories about a recent study wherein dogs were trained to lie still enough in an fMRI while listening to humans talk to them. The results indicated that our evolutionary partners processed emotional tones on the right side of their brains and specific words on the left, just like humans. The more we study dogs, the more we find how smart they are and how much we have adapted to each other for interaction. Check out the research done by Brian Hare and colleagues.

I first read about the fMRI study in Science News from 10/1/16. It provides a good summary (as they usually do—what a good magazine) and then they ended the article with the idea that because dog-human relations have only developed over the last 30,000 years, too short a time for evolutionary progress to produce such linguistic abilities, “some older underlying neural mechanism for processing meaningful sounds is present in other animals”.

This highlights for me the theoretical mystery on the biological nature not just of language but of symbolization in general (so it includes art as well). As I have said before, understanding symbolization is the holy grail of understanding ourselves biologically, and so let me render a conceptual outline of this mystery. First consider the bond between dogs and humans and that emotional communication through voice (and sight) is processed by the right side of the brain in both of us. We have researched this broadly in humans as intonation or non-verbal vocal communication, and/or kinesics. All of this to my mind is empathic communication and its processing is right sided; we find a cortical area for its integration there at the tempo-parietal junction that I call Empathy Central but the academics call ToM (Theory of Mind). Do dogs have an Empathy Central area? Unknown for now but I am taking bets they do and planning on how to spend my winnings.


Looking left, currently bored

Next consider this basic feature of lateralization. The right side processes emotional expression and empathic communication just like it processes the current perceptual-motor domains, i.e., the right side processes the specious present. The left side then directs its energies towards information displaced in time and space, initially as a supplement to the specious present by recognizing and recalling information and then increasingly as a virtual domain for information to be composed independently from current objective events. Language, as a symbolic function, is so powerful because it allows us not only to control the input and retrieval of displaced information from memory, not only because it allows the composition of new information from imaginal processes, but also and especially because it allows us to communicate about what isn’t there in front of us but exists only in our minds, apprehensible only to oneself and in symbolic communication.

So when the article ends by asking what the underlying neural mechanism might be, my answer is not about language but about its precursor in the symbolic control of displaced information. Why should that be lateralized to the left? Ah, because timing is important. The right side matures at a faster pace than the left, due primarily to the differential effect of testosterone which slows the left’s maturation more than the right’s (and so males show more distinct patterns of lateralization and more language problems from sometimes too slow a pace on the left side). The right side develops the capabilities to process current information early on while the left side is coming online, so to speak, a bit later, and when it does come on line, it is not totally in sync with the right sided processes for the specious present. Its information is displaced (read out of sync) almost from the beginning of the incipient specious present. Symbolic processes enable finer, more powerful control of such displaced information. So the right side focuses more on the current coin of interaction, i.e., empathic communication, and the left side more on non-current, i.e., displaced, information. Verbally this relies on lexical knowledge, the processing nexus of which is in the left temporal-parietal junction. As we learn more about animals, especially mammals, we will find the precursors of these underlying neural mechanisms in virtually all of them. You can count on it.

A couple more quick notes. It would seem likely that dogs were domesticated and became our close buddies because the genetic streams feeding their evolution ran close to ours—our brains are sympatico in how they process social information.   Human genetic streams, however, also evolved a lower larynx and hyoid bone, greater breath control, and oral-facial musculature thereby enabling articulate speech and even more critically to our humanity, gave rise to longer cortical fasciculi. The arcuate fasciculus is a prime example here. Remember that it carries the surface structure of words on the left side between front and back so that we can repeat what we just heard said. On the right side it might could carry emotional expressions for mimicking. (See my most popular post from 4/24/14, Arcuate fascicles, mirror neurons, and memes). The important feature here, however, is that these long fasciculi facilitate the composition of invariant information forms, e.g., words, discrete emotional forms, and their expression. (And how about art and its special modes of symbolization? Ah, beautiful). The creation of these invariant forms is what enables the separation of deep and surface structures and the subsequent development of syntactic control of their compositional connection. The creation of these invariant forms, both long-standing (lexical items) and in passing (conversation), by the welter of connectome activity in the presence of ambient flux is the remarkable basis for humanity’s intelligence and it has grown from deep roots.

Finally, remember to mark your calendars for Mammalian Heritage Day on November 2 and celebrate those roots. Travel on.

Theta moments, completion of a composition, & cortical fasciculi

Following up from last post: Ah, theta moments, specifically hippocampal theta moments when the apprehension of something new instigates the mental response composing a new situation. I have written about this several times before. Theta waves manifest during key behaviors, simple ones like the chicken’s head bob (yes, almost everything is new because so little is old) or a rat’s step (yes, safety demands almost constant appraisal and memory for location to gain food or avoid danger) or more complex ones like a cat’s orienting response (of what interest is that and should I bother the cat must ask) or a chimpanzee’s expression of bewilderment when an expected treat does not materialize (now what does this mean and what should I do?). Theta is named for the slower waves which accompany these behaviors and signals that diverse areas are focused on the salient event. As the animal processes incoming information the theta disappears as faster, more irregular waves in diverse areas indicate specific information is being processed to help delineate the contextual situation.


The hippocampus is old, deeply embedded cortex. Cortical input flows into the thicker end and the output from the narrower part.

The important thing here is that the hippocampus receives highly processed perceptual information (forms, movement, id of conspecifics, predators, etc. are more automatically recognized) that it processes and then sends the results on upward to the frontal areas engaged in planning and implementing actions and downward as it contributes to the emotional processing carried on by the limbic system. As I have noted before, the hippocampus is way cool. Consider, then, that a theta moment is when the animal formulates a new situational gestalt, a governing form or proto-narrative structure developed from ambient information as discussed in my last post, and then other processes fill in the details, i.e., they finish the composition with perceptual analyses and emotional streams. Of course, these theta moments are actually completed when the animal initiates its next action, e.g., fight or flight, eating, exploration, retreat, or social behaviors.

We humans have a strong network of cortical fasciculi or fiber connections between and among perceptual areas and frontal action areas. These fibers connect the same areas which contribute to hippocampal input and receive its output to initiate the plans and structure of behaviors but they bypass the hippocampus and its situational construct of the immediate ambient and the pressure to act accordingly as well as with the emotional dynamics governing the animal’s responses. By doing so, bypassing this involvement through lower channels, these cortical fasciculi would seem to permit the processing of information apart or displaced from ambient and emotional conditions. What happens to our theta moments there?


Hippocampal theta, remember, first marks something as new or salient and then holds that as a gestalt for the brain to fill in needed information. In this some information, even as it is noticed as new, is held as invariant or as old, so that it can operate as an anchor for further processing of variant information. With the systems connected by the cortical fasciculi, old and new are not contingent upon perceptual notice but upon, at least for us, the gestalts and composition of symbolic information, e.g., the syntax for a linguistic utterance, the intuitive form for aesthetic pieces. So theta moments may be relegated to eurekas, epiphanies, ‘sudden’ insights, realizations, or coming to your senses, etc., the function of generating an invariant form as an anchor for further composition may now continue independently of hippocampal circuits.

I do not want to go into the sleepy land of complicated thinking here about propositional forms based upon the invariance of the verb case frames or how the arcuate fasciculus of the dorsal loop

arcuate fasciculus

helps to maintain the invariant relationship between phonemes and articulatory movements (see recent post on dual loop model) or the invariance of memes as cultural constructs or the invariant memories held in place by guilt or joy, etc. I do want to say that artistic inspiration, that theta moment, major or minor of ‘aha’ or ‘ummm’, when the artist intuits the commanding form and begins to add newly variant elements to compose his or her artistic piece, is one of the most important moments in terran biology and that when we evolved to do this, the universe, well, as it were, sort of, changed for the better. Life began to create new out of the old on its own intentionally without relying on the universal flux of the environment that is slowly, entropically degrading to ‘om’ and that creation was based upon our feelings of fitness, aesthetics, or our sense of beauty.

Now last post I said that Daniel Stern’s understanding of the ‘proto-narrative envelope’ [commanding form) and vitality affects [vital feelings abstracted from experience] from his studies of infants was important. Consider that state of an infant known as the quiet alert state that occurs after feeding. Then the child is most available for social interaction, most readily engaged in rhythmic social exchange and in playful affect modulation. Then the parent helps the child develop the capability for positive affect through engagement. And then it seems to me, the infant sees its whole life as a theta moment as he or she begins to accrue the schemas needed to interpret experience and live a human life. Artistic inspiration and effort has often been compared to these child-like energies and for good reasons. We can see this clearly in the quiet alert state now open for reflection, inspiration and beginning a composition. Artistic creation is clearly related to such youthful joy and we sense this in many artistically talented people (though perhaps cloudily in the tormented geniuses of historical stature). And this has biological roots. I will travel on now to work simply in the garden.

important stuff

I now return to Patel’s fabulous book, Music, Language and the Brain, where he relates research into the expressive timing of good musical performers. I posted about this some time back but a review is in order. Theoretically all eighth notes in the same time signature should be the same length, but in reality they vary a good deal with an average length of 652 milliseconds +/- 250 msecs in one study, so that eighth notes range from 400 msecs to 900 msecs. The important aspect here is that the variation is not random but purposeful, intentionally done as a way to convey the style and emotional tone of the performer in playing the piece. When music is electronically manipulated and note length is varied, listeners can tell the difference, and if the music is machine generated with all the notes standardized to some length, e.g., all eighth notes are 652 msecs, that music lacks vitality and is clearly machine made, i.e., mechanical and not musical, and listeners reject it.  Consider the musician, say a pianist, as they play a piece expressively and to do so must intuitively vary note length by such very small increments, say a fifth of a second or less. Quite a feat of motor control, and now I come to a greater consideration: how does that expressive feeling that guides motoric movements come about? Oh, my, let me list, in no particular order, what might be the biological components:

–the self, whatever that is that gives rise to artistic touch or vision or voice. This is hypothesized by Damasio to be a very complex group of brain functions from the brainstem to neocortex.

–social intelligence or that understanding which enables one self to communicate subtle emotions with another self or which contributes to well received aesthetic expression. This coalesces in the right hemisphere, we know, around the temporal-parietal junction.

–musicality in general is seen as a right hemisphere function but professional musicians rely on the left side for some important functions. Perhaps this shift in laterality comes as a musician learns to sight read (certainly left sided) and grows more automatic and facile with the movements needed to produce music.

–and now I bring in the dorsal-ventral loops composed of the long fiber networks of the cortex. I will say simply now before explicating the idea more in the following paragraphs that the dorsal loop, e.g., the arcuate fasciculus, facilitates the regular repetition or accurate mirroring of a heard or known passage, while the ventral loop, e.g., the uncinate fasciculus, facilitates the rendering of meaning and novelty from what has been mirrored. (Please see my post on 9/27/15 to better understand my use of ‘mirroring’).

I have been studying an article by Michel Rijmtjes. Corneilius Weiler, Tobias Bormann, and Mariacristina Musso in Frontiers of Evolutionary Neuroscience from 3 July 2012 entitled “The dual loop model: its relation to language and other modalities”. The dual loop is the dorsal and ventral loops mentioned just above. They focus on the left side because they are working on understanding language, so my extrapolation to the right side is just that, mine. Also, their work, like most of our neuroscience examining particular human abilities, focuses on reception, mostly because one can study the brain’s response to a specific input. Studying expression is more difficult because how we motivate, generate and enact behavioral impulses, especially those with aesthetic attributes, is currently lost in the neurological depths from whence expressive behaviors emerge. Aesthetic ones are the most problematic in this regard, because creative processes are the most distant and dissociated from the reception of input stimuli and a highly original and creative symbolic expression from an individual self. So with that in mind . . . .

These authors review many studies and hypotheses about how human language can be so different from other animal communications, i.e., a lot here to digest. The two loops are actually structures I have discussed before but did not know at the time they were part of a more comprehensive model. Both of these loops connect back (input/receptive) and front (output/expressive). The first of these is called the dorsal (sort of over the top of the brain) loop, exemplified by our old friend the arcuate fasciculus (remember it enables our ability to repeat words, so it is an important part of the mirror system) that connects Wernicke’s area of the auditory cortex in the temporal lobe with Broca’s area in the motor cortex of the frontal lobe. (See my post, Arcuate fasciculus, mirror neurons, and memes from 4/24/14). In my thinking the arcuate fasciculus organizes surface structure, the mapping of sound to motor patterns thereby enabling meanings to be understood and expressed. Here is its pictorial representation.

arcuate fasciculus

The second loop is called the ventral (sort of running along the sides of the brain) loop, exemplified here by the uncinate fasciculus that runs from the temporal lobe to the frontal lobe. It does not originate solely in Wernicke’s area nor does it end solely in Broca’s area but rather from areas cradling both of the dorsal junctures. Here is its pictorial representation.


The ventral loop is less concerned with organizing surface structure for mirroring and more with organizing deep structure, that poorly understood function whereby linguistic meaning is derived from thinking, so that we can understand and express not just words and sentences but the conceptual workings underlying them. The dual loop hypothesis focuses on how these two systems interact in the special ways required for human language.

Oh so complicated and much more can and will be said at some later time about this neurolinguistic hypothesis, but I want to swing from the left side to the right side, from language to the social intelligence captured by our musicality. (and this post is getting longer than usual already). The dorsal and ventral loops are also on the right side; we know less about them for a variety of reasons both experimental and conceptual. In my most popular post of all time cited above, that continues to gather hits to this day, I discussed the arcuate fasciculus (AF) on the right side, citing new research that confirmed it existed there (for a long time it was thought to be only on the left) and also that it seemed to help to mirror social communication. I speculated that maybe gifted mimics, such as Jim Carey,Tina Fey or Rich Little, had a stronger AF system that enabled them to mirror another’s emotional expressions, so that they can sound like and mimic facial expressions of some public figure, say President Nixon, Sarah Palin or some other public figure.

Now we can develop the dual loop hypothesis for the right side. Rijmtjes and his colleagues report that experienced musicians have a larger AF than the rest of us, most probably because they have practiced playing and mentally rehearsing musical pieces. The AF here would seem to play an analogous role from the left on the right side as it helps to mirror a piece for performance, either from hearing it before or even sight reading it, so the right sided AF would help to map the sounds and motor patterns for their playing. This is the dorsal loop’s primary function.

What of the ventral loop on the right side? If it organizes thought and semantic meaning for language on the left, what might it do on the right? Ah, what is the artistic import of any musical piece or any artistic production for that matter? (see post 11/4/15 Musical brain and artistic import) It is not standardized through convention the way words are; artistic import, to echo Susanne Langer’s writings here once more, is not from a discursive, linear symbolic form but a presentational, non-linear symbolic form. It is a symbol for a particular experience of felt life, and that is one of the beautiful complexities of our minds.

Returning to where I started, how does a musician play with exquisite feeling some piece from musical notation? How does a pianist play with vital variations of note length, tempo and loudness to give a coherent and musical rendering of the piece? Part of the answer lies in the dual loop hypothesis, wherein the dorsal AF supports the mirroring of the piece (connection between sounds and motoric production) while the ventral supports the variation of the individual performance in a (hopefully) aesthetically pleasing way. It does so by engaging the systems listed earlier, the self, the emotional responsiveness and social intelligence of the performer along with their sense of musicality (likewise the composer though that is even more complicated).

I have gone a long way to connect to the beginning and I want to close with yet another line of thinking I read about recently in the Origin of Music. A very unusual man by the name of Manfred Clynes developed, among his many efforts that included coining the term ‘cyborg’, the science of sentics. This focuses on how emotions are communicated through patterns of touch, their tempo, strength, etc. As an example, Clynes had Americans communicate how they were feeling different emotions through touch and then tried these out on Australian aborigines, who were able to decode the emotions so presented. Clynes also translated this notion to the touch of a musician as he or she plays their instrument and the piece being performed. Clynes used this knowledge to program a computer to play music with a human feel and listeners could not pick out the machine version. Clynes is clearly a genius; in addition to being an engineer and neuroscientist, he was also a concert pianist who played for and with Einstein, what used to be called a polymath.  More later. Now I think it is time to turn on the old ipod and listen to a vital aesthetic form contained therein.

the musical brain and artistic import

A longer post here than usual:

So I have finished Jourdain’s Music, the Brain, and Ecstasy; not sorry I read it and appreciate the opportunity to quibble. Chapter 7 discusses musical understanding and he contrasts the meaning between music and language. I liked his presentation of deep and surface structure (from Chomsky) and have long used this in my thinking. I did not find his presentation of “meaning” very knowledgeable, but then I have recently read Patel’s Music, Language and the Brain. Patel does not question the difference between the deep structures of language and music so much as to hypothesize what these might be.

Both Jourdain and Patel base their thinking on empirical studies, clinical and experimental. To no surprise of the initiated, Susanne Langer explored the differences between art and language through her philosophical musings back in the 1950s and further researched their biological implications in her 3 volume Mind: An essay on human feeling. If fortunate, read Langer’s 1957 Problems of Art, a clear exposition of the difference between discursive symbols, exemplified by language, and presentational symbols, exemplified by art. (For further understanding along the philosophical vein, read her Philosophy in a New Key and especially her aesthetic statement in Feeling and Form). Presentational symbols are virtual constructions in which each element has no meaning independent of the total gestalt, as opposed to discursive elements that are lexical items of steady and stable meaning no matter the context. Further, presentational symbols are then not constrained by the necessities of linearization in the form of a grammar transforming deep to surface structure, e.g., sentences. Instead, presentational symbols express some symbolic formulation of an experience in a complex, contextual, non-linear structure, i.e., painting, music (yes, I know music is half linear but the elements depend upon the total gestalt for significance–makes it hard to study empirically), sculpture, architecture, dance, drama, poetry, fiction, etc. In Problems of Art Langer determines that linguistic meaning is just that and another term is needed for the deep structure of art and this she terms ‘import’.

Our challenge, then, is to understand how the artistic brain generates and expresses import and how this is different from linguistic meaning. Oh, I could expand here a long time but strive for short posts. Let me just start with a discussion of hippocampal functions as perceptual processing flows back to front into areas for action, i.e., motoric behaviors, contrasted with the cortical fasciculi running between posterior and anterior areas, e.g., arcuate fasciculus, superior longitudinal fasciculus, and uncinate fasciculus.

Remember that the hippocampus determines old and new information, thereby initiating mnemonic input and retrieval, as well as cooperating with limbic structures involved in valence, e.g., does it feel good or bad or what? Information from the visual, auditory, and bodily orientation systems converge for integration in the entorhinal cortex of the temporal lobe before merging into the hippocampus that then communicates with frontal areas.


In a post of long ago (try 2/14/14& 4/11/14), I discussed old/new processing across species. Basically, as the brain evolves with a MEMBRAIN and its interior mind, old/new shifts from a concrete and immediate context to virtual one displaced from the time/space context. Thinking about musical import helps to understand how this shift happens.

Consider again the long cortical fasciculi. The superior longitudinal fasciculus is a complex group of fibers arising from the O-T-P (occipital-temporal-parietal) conjunction and communicating with frontal areas. The arcuate fasciculus is a part of that and communicates specifically the motor patterns for speech on the left side and, somewhat more speculatively, motor patterns for empathic communication on the right. Other parts serve to help control attentional processes.

Sobo_1909_670_-_Uncinate_fasciculusarcuate fasciculus

The uncinate fasciculus arises in the anterior temporal lobe where it merges through the entorhinal cortex into the hippocampus and then communicates with prefrontal areas.

The idea is this: the hippocampus is bound to ambient processing of the old/new in the here and now and survival and social; the cortical fasciculi permit the processing of old/new in the mind with mental structures in the subjective interiority. While the arcuate fasciculi carry information pertaining to the surface structures to be expressed and received, the other fasciculi contribute to the construction of deep structures, i.e., linguistic meaning and artistic import, using old/new information the definition of which is not constrained by ambient and emotional conditions and is controlled by the processes of symbolic generation.


What about music? Like all art or presentational symbols, its import comprises experiential information from the ambient and emotions in a whole gestalt that has been constructed through control of hippocampal mediation, e.g., the autobiographical associations with the tune as well as the emotional arousal, and the non-immediate, now virtual mental forms here presumed to be mediated by cortical fasciculi. Aesthetic sensibility typically is understandably more right sided given its focus on the present context. This is in contrast to linguistic meaning that is more left sided given its focus on contextually independent elements. Music, especially harmony and melody, derives from the aesthetic processing of sounds to render artistic import either for reception (quite common) or expression (not so much), thereby rendering some vital emotional knowledge about life into communicable form. And then we have ear worms, segments of surface structure looping probably through the arcuate fasciculi until something else rings in its place. Listen up and travel on.

Lucy in the sky with diamonds, Lucy . . . .

Lucy in the sky with diamonds, Lucy . . . .

Memes, mirroring & tropes

Since Richard Dawkins coined the word ‘meme’ in his 1976 book, The Selfish Gene, we have had some difficulty defining the word more specifically. Despite the intuitive sense that the word does capture something meaningful, the smallest unit of cultural replication, a science of mimetics has not gained widespread traction. Of course, knowing what culture actually is would be a big help. Other primates show cultural differences between groups. Chimpanzees and bonobos are different species, though very much like genetically, and their ‘cultures’ are quite different. We can even see such differences between different groups of chimpanzees. By we I mean those who study and are very knowledgeable about these animals. Other scientists have documented that some species of birds have different songs characteristic of geographically isolated groups. Do these animals operate with memes? Human culture also varies according to geographical isolation as well as by temporal change. Five and six hundred years ago Western culture comprised some memes supporting the divine right of kings, i.e., royalty=sun=god=supreme power=do what they say or else. Some cultures continue to transmit such memes about their leadership, while we now scoff at the notion (and hopefully argue against those who challenge the separation of church and state).

Of course we know roughly what human culture is, even though we have difficulty breaking it down into the measurable, empirical units that are memes. And of course, our culture is different from those of other animals’ because ours in composed through our superb empathic capacity and especially through our distinctive symbolic ability. Part of the difficulty defining memes comes from just that: our protean symbolic abilities that foment society wide memes to form our culture. While we electronically enhanced humans quickly think of emojis and emoticons as memes, these are actually just icons, simple signs standing for one thing, e.g., happy face=happy, LOL=humor maybe ironic, etc. Our culture is a much richer phenomena; it is more an ecology of memes that regulates social relationships than cartoonish marks that serve as shorthand for social niceties or the thoughts punctuating communicative transitions. Like the ones of royalty’s divine right, memes are the coin of exchange between individuals and their society and they change and shift with cultural evolution. Individuals take in societal expectations for cohesion and contribution and then social developments slowly modify what those are. Take, for example, the meme of ‘women’s liberation’ from the 1950s on. This change of role expectations resulted from a complex of factors, i.e., contraceptive medicine, employment patterns, educational advances, voting, etc. The meme operated across society in this change of cultural roles.

So memes mutate and culture evolves through a complex dialectic of symbolic interaction. No wonder they are difficult to define very precisely, and this is only one side of the problem. We also need to understand how our brains receive, produce, and process memes psychologically. Memes are only as effective as they structure or regulate our mental processes; they provide guidance for each individual in that social group. Someone who rejects the memes (“the King is a man same as any of us” sort of thing) is a rebel or at worse, unsocialized, or at best, a leader of cultural change. How do we understand this process of meme transmission and meme mutation? In answering this question we look to psychology, sociology and neuroscience hoping to find a bridge between biological science and cultural exchange. We are explorers here; no map shows the terrain between evolutionary biology and the social sciences. The liberal arts must be close by, but where, oh, where?

In place of ‘replication’ Dawkins and others generally use the term ‘imitation’, an old stand-by from the dawn of psychological science. Memes are transmitted through imitation and change through imperfect imitation, much like the old whispering game. While this helps some to clarify, it also limits our view. We may have no map connecting evolutionary biology and the social sciences but neither do we need obfuscation, especially when we have a better alternative. In the 1980s Giacomo Rizzolatti and colleagues discovered neurons in monkey brains (a finding since extended to other species) that lit up when the animal performed a particular action, e.g., cracking a nut, and also when the animal observed another performing that same action. Instead of naming these ‘imitation neurons’, they felicitously called them ‘mirror neurons’. Imitation is ‘monkey see, monkey do’; mirroring is ‘monkey see, monkey do but only in the mind’. That is an important difference, the difference, as it were, between Skinner and Freud.

Mirroring comprises imitation and even the distorted imitation like the fun house mirrors at the fair, but the truly important feature here is the silver backing that represents or brings forth the endogenous, autonomous and autogenic impulses of a vital mind. We humans, and indeed other animals, bring as much to the image as our sensory organs do, even more in our case. This is a mirror more akin to the Mirror of Erised in Harry Potter that shows viewers an image of their own desires. This is a mirror wherein reflections may come from without, may be held and changed, and even more may come from within.

Our quicksilver brains carry out mirroring in many ways through different systems and for different purposes. Consider the initial discovery. We, along with other primates and some other animals, monitor others’ actions more or less automatically and sometimes quite closely and consciously. We see someone pick up a cup and drink tea, our tea drinking motor cells light up. We see someone put their hand down as if they were going to drink tea and our drinking mirror system lights up. We see someone glance at the teapot and fix them some tea. Psychologically such a system makes cooperating easy to do and it helps us to learn by imitation, e.g., how to knap a stone for a sharp edge. It also lets us modify the motoric protocols for a better performance. Some animals can use this system in a playfully false manner, like one dog feinting one way and then going another in order to trick the other dog or sort of like a football or basketball player with the ball faking out the defensive player. Sometimes we mirror too closely and lose points in the game.

Mirroring systems are more ubiquitous than we might suppose. We mirror each others’ faces, thereby taking in information about another’s mood, manifest intention, etc. Our good dogs do this with us as well. Family members and intimates communicate without communicating, by communing empathically, cooperating (or not) in a variety of tasks without explicitly planning it. Being familiar together brings with it a wealth of engagement in countless small ways and often unappreciated until later. I am thinking of watching a grandfather with his young grandson, who is rather unconsciously though perhaps admiringly striking the same pose as his elder or those living with a loved one over a long time whose shared context and current empathic communication almost creates a unity of mind making it easier to finish the other’s thought or to remember what the other forgot. Our phenotypic personality develops as our brain’s mirroring systems mature and we internalize features of our important persons even as we bring our own native abilities to our relationships.

Our mirror systems operate across sensory modalities and with both concrete and symbolic information. The arcuate fasciculus (AF) is a long fiber system that connects Wernicke’s area (auditory understanding) and Broca’s area (expressive speech); it helps us to mirror what we heard the other say. When the AF is severed, the person cannot repeat what they just heard. The AF carries the auditory signal to the speech articulation system in a way that facilitates the motoric mirroring of speech. In conduction aphasia due to brain injury when the AF is disrupted, the person may understand and even answer but cannot repeat what they heard. Then we have the opposite when some children with autistic spectrum disorder are echolalic and can repeat anything clearly but understand very little. Mirroring starts the process of deeper social connection and understanding. What is true of the left arcuate fasciculus for language is also true of the right AF for affective communication. Even more basically some might posit that our sensory organs ‘mirror’ what is out there, reflecting the sensory information in the virtual figures of neural processing.

Memes are the figures of cultural mirroring. They are the means whereby important social/cultural information is brought forward easily into the members’ minds. They are like echoes sounding through the group that enable us to dance together. Memes are socially constructed and shared, and to be effective, they must channel individual efforts to contribute to group responsibilities. Here we come to the difference between memes and tropes. Memes replicate and function well only when they spread accurately, i.e., the cultural contagion of these information viruses spreads as our mirrors reflect with little distortion, etc.  Tropes are an artistic element; they function well in the individual’s composition of the artwork and then with any other individual culturally similar enough to understand the trope’s figure. To comprehend Elizabethan literature, we must understand the meme of royalty=divine=sun=better do as they say. To appreciate Shakespeare, we must mirror and feel fully the tropes he wrought, e.g. “It is the east, and Juliet is the sun”. Tropes are not standardized or culturally mirrored, or if they are, they function as clichés. Ho-hum. Tropes are vital, intuitive renderings from the depths of the mirror; they are not reflective but generative, and they express some important feeling about our particular, individual experience. Tropes, indeed all art, provide the silver backing of our mirroring; without them we would just be imitators with an astonishingly impoverished culture by current standards. And that is really why I like the term ‘mirroring’ more than ‘imitation,’ and that is why the study of art is so important to biology and neuroscience. We may never understand the quicksilver creativity of intuition; we certainly won’t in the positivistic sense of understanding, which is bent upon exerting control, but I hope we come to appreciate more this manifestation of life’s vitality, as uncontrollable as it may be! Our science is not limited to empiricism, as necessary and important as hypothesis testing and data are, but also includes the paradigms we creative Humans bring to our endeavors.  Here is a place of rest before I travel on, but coming in the near future a post about the dual loop model of language, its wider context and the temporal parameters of mental information.

Arcuate fasciculus, mirror neurons, and memes

I have wanted to get to this post all week but the farm has taken all my time and energy.  I hope tomorrow’s rainy forecast verifies for many reasons.  Onward.

The arcuate fasciculus (AF) is a horizontal bundle of nerve fibers running between the posterior Wernicke’s area in the auditory cortex and the motor cortex associated with Broca’s area in the front.  Mirror neurons are motor neurons which fire/respond when an animal sees another animal perform some action; these neurons would be involved in performing the observed action but in their mirror functioning, they just respond to perceptual input and are not part of a behavioral enaction.  Memes, as conceived by Richard Dawkins, are units or forms of cultural meaning transmitted through social communication.  Going from my post on 4/7/14 about the MEMBRAIN, i.e., our brain functions as a membrain around our mind and some communication is privileged so its reception and expression is facilitated by specialized channels through the MEMBRAIN.


We have known about the AF for a long time because damage to it results in conduction aphasia, i.e., the person cannot repeat the words they just heard though they may be able to comprehend and respond conversationally.  Evidently the AF enables a person to repeat verbatim.  Long years ago I worked with a young autistic boy who understood almost no language and uttered no meaningful speech but who could and did repeat (echolalia) what was said quite accurately in a sort of inverse of conduction aphasia.  So this part of the MEMBRAIN filters phonological information and passes it straight through to areas concerned with motoric output.  Maybe it helps us repeat things we do not initially understand as an aid to comprehension or to repeat things we do understand for better memorization.  The AF also seems to help with the phonological analysis needed for fluent reading (another specialized channel).  I finally got around to reading an article about this by Yeatman et. all. in the Journal of Cognitive Neuroscience 23:11 about the AF and phonological abilities.  Their findings were interesting but what really caught my attention was the basic work they did imaging the AF  in both the right and left hemispheres. While some neuroanatomists have thought the AF was strictly a left sided structure, being involved with language as it is, it turns out that careful imaging also reveals an AF structure in the right hemisphere.  Is it concerned with language?  Or does it participate in the usual right hemisphere functions of emotional communication, prosody, and pragmatics?  Does it carry information about emotional expression, so that we can mimic the expression of another?  The AF is variable on both sides and in both sexes; could gifted mimics like Rich Little or Jim Carrey, have a more prominent right AF? Does someone who is exceptionally empathic or tuned into the expression of microemotions have a more developed right AF?

Thinking about the AF I considered how similar its function is to mirror neurons, which were only discovered maybe 20 years ago.  When a monkey sees another monkey pick up a nut, the neurons involved in picking up a nut fire in response to the percept.  Different neurons fire if the other monkey picks up the nut to give away or to crack.   The AF is a special exemplar of long fiber bundles connecting front and back areas but other larger tracts such as the superior longitudinal fasciculus connect many such areas.  Again, specialized channels in the MEMBRAIN.

Now consider memes, cultural bits which pass into and out of our minds with noticeable facility.  We hear a snippet of music and play a longer passage back in our minds sometimes all day long.  Or we talk about time being up, going faster, crawling, etc and understand easily the conventional metaphor of our culture.  Memes are probably supported by more dynamic functional organizations involving non-specialized neurons, unlike the AF or mirror neurons but they still provide flexible specialized channels into the mind.  There’s a lot more to consider here but dinner calls.