Language and the Brain
At the risk of becoming another of Noam Chomsky’s “paradigm example(s) of a futile tendency in modern speculation about language and mind”, I want to start this discussion by offering some comments on the phenomenon of language from the standpoint that the many, often apparently contradictory texts on language which so crowd the bookshelves fall broadly (for the purposes of this essay, at least) into three main groups. These can be summarised as those that address language at the evolutionary or genetic level of the species; those that concern themselves with language (primarily language acquisition) à propos the individual; and those that attempt to explore the mechanisms of relationships between the individual and the linguistic community in which s/he is embedded.
Although there is sometimes quite noticeable variation in methodology (as between philosophical inquiry and extrapolation from laboratory findings, say) on the whole I would argue that these approaches or theories are not necessarily mutually exclusive nor oppositional – indeed, taken together it can be argued that by offering their different perspectives they focus attention on what might be termed (for want of a better word – something to which I will return) the ontological nature of language. By this I mean the sense in which language on the evolutionary level is inseparable from concepts of what it is to be a sentient human being and the apparent qualitative differences which separate us from our closest genetic neighbours; the fact that on the individual level language is an organic part of the individuating process, perhaps the primary means whereby we become; and the awareness that on the social level language is the prime mover which shapes, facilitates and complicates our interactions with the otherness of the world.
Whatever the particular validity of a particular theory about the evolution, acquisition or nature of language it seems to me impossible to ignore the underlying physicality of the language process, its brain-centredness – as Nicholas Humphrey points out in A History of the Mind:
“In short, animals first had ‘minds’ when they first became capable of storing – and possibly recalling and reworking – action-based representations of the effects of environmental stimulation on their own bodies. The material substrate of the mind was nervous tissue, which in higher organisms became centred in a ganglion or brain; and it is to be remarked that even in animals like human beings the neural tube which forms the brain during embryological development derives from an infolding of the skin.”
Neurological research over the last two centuries confirms that language is generated and understood in the cortex, the outermost covering of the brain – more specifically in the left frontal cortex (Broca’s Area, named after Paul Broca) and further and lower back in the posterior temporal lobe (Wernicke’s Area, after Karl Wernicke), the two areas being connected by a dense bundle of nerve fibres called the arcuate fasciculus. Apparently, both areas are found in the left hemisphere in some 97% of people. Their work was completed just after the middle of the 19th century.
Some hundred years later Penfield and Jasper described how electrical stimulation of certain areas of the brain appeared to block language function; and in the late 1980s Ojemann demonstrated (also through electrical stimulation experiments) that there can be large individual differences in the brain area that is important for language.
Brain imaging techniques continue to provide data. PET (Positron Emission Tomography) scans show that many of the expected areas of the brain have increased blood flow during language tasks – and that areas in both hemispheres can be activated, suggesting that even the ‘non-dominant for language’ hemisphere has some physical involvement in language. Interestingly, if the ‘non-dominant for language’ hemisphere is damaged people have problems communicating the emotions involved with language – conditions known as aprosodias, or the absence of prosody (the ability to endow language with rhythm and feeling) and alexithymia, or difficulty in recognising or describing feelings and emotional states sometimes coupled with the postural rigidity and lack of expressive facial movements often found in stroke victims.
More recent research – with a technique called diffusion tensor MRI (Magnetic Resonance Imaging) – has revealed in more detail a third area in the parietal lobe at the top of the brain which is a separate roundabout route connecting Broca’s and Wernicke’s Areas. Named Geschwind’s Territory (after the American neurologist Norman Geschwind, who had pointed it out as an important language region in the 1960s) it seems that this is important for language acquisition in childhood and is the last area in the brain to mature – and the completion of its maturation seems to coincide with the development of reading and writing skills, suggesting a potential link with such communication problems as autism and dyslexia. Rudimentary forms of these pathways have been found in the brains of monkeys, suggesting that language evolved at least partially from changes in pre-existing networks rather than from the appearance of new brain structures in early hominids.
More importantly, it suggests that language acquisition is an innate mechanism chemically triggered and/or genetically determined whereas language itself is learned – there seems to be a stage in maturation after which learning a language becomes problematic. Most people who learn a foreign language later in life speak it with a discernible accent, for example, yet children reared in a multi-lingual environment generally don’t have that problem. As Chomsky said, if French were innate I would speak it – but
“(It is) the mechanism of language acquisition (that) is innate. In a given linguistic community, children with very different experience arrive at comparable grammars, indeed almost identical ones, so far as we know. That is what requires explanation. Even within a very narrow community – take the elite in Paris – the experiences are varied. Each child has a different experience, each child is confronted by different data – but in the end the system is essentially the same. As a consequence we have to suppose that all children share the same internal constraints which characterise narrowly the grammar they are going to construct.”
So while the brain-centredness of language allows us to recognise observable stimulus-response processes common across the species it also indicates the mystery of how those processes work within the separate individual – and in so doing captures something of the slipperiness of the phenomenon in its social contexts, as per the quote Humphrey gives from George Eliot’s The Mill on the Floss, where Mr Tulliver says to his wife:
“No, no Bessy … I meant [what I said] to stand for summat else; but never mind – it’s puzzling work, talking is.”
© 2019 Mike Liddell
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