The human mind appeared on Earth with astonishing suddenness. Just 70 000 years – the merest eye-blink of geological time – covers our ancestors’ transformation from smart ape to self-conscious Homo sapiens.
On the far side of the evolutionary divide stands Homo erectus, a clever beast with a brain almost as big a modern human’s, a simple tool culture and a mastery of fire – yet mentally still somehow lacking. On our own side stands Homo sapiens with the rituals and symbolic art – the cave paintings, beads and bracelets, decorative lamps and burial graves – that mark the arrival of a self-aware mind. Something sudden and dramatic must have happened, and it is this event that could be the starting point for human consciousness.
Maybe the brain merely grew beyond a critical size and lit up like a light bulb. But a more plausible cause for the great advance made by Homo sapiens was the development of modern speech or, to be precise, the ability to internalise speech and so create a controlling ‘inner voice’.
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The suggestion that inner speech could be the key to understanding the special attributes of the human mind is hardly new. Even the Ancient Greeks and the 17th-century philosophers of the Enlightenment – particularly Thomas Hobbes – made reference to the possibility. And Charles Darwin wrote in The Descent of Man: ‘A long and complex train of thought can no more be carried on without the aid of words, whether spoken or silent, than a long calculation without the use of figures or algebra.’ In the 1930s, the brilliant Russian psychologist Lev Vygotsky tried to rebuild the whole of psychology on this insight – an attempt that was defeated by his early death from tuberculosis and the suppression of his writings by the Soviet authorities.
As a result, it is only during the past ten years or so that it has begun to dawn on psychologists that inner speech may have a role in fashioning the human mind itself, going far beyond logical thought to include the entire apparatus of our higher mental powers. Much of the evidence is being gathered outside the boundaries of traditional psychology by researchers in fields as diverse as anthropology, sociology, linguistics and educational psychology. But with the findings now beginning to filter back into psychology, a model is taking shape which revolutionises our very concept of the human mind.
Instead of attempting to reduce the whole of consciousness to something biological – a collection of neural circuits or information flows – psychologists are beginning to follow a more complex dual model. This approach continues to reduce the animal foundations of the mind to neurology, but seeks the explanation of the special human extras in a very different direction, in inner speech, childhood socialisation and culture. In separating these two elements, researchers may at last be able to distinguish self-awareness from raw animal consciousness – two facets of the human mind left hopelessly entangled by the traditional reductionist approach.
LINGUISTIC FAULT LINE
Memory research is one field that is beginning to reflect this shift in thinking. In the past, it has been normal to treat memory as a single, unitary biological system. Granted it had many parts, such as short and long-term memory. But it seemed safe to assume that all these parts evolved together and so were constructed out of the same basic – presumably neurological – stuff. Because of this, most researchers believed that human memory could be treated as a scaled-up version of animal memory: our bigger brains might mean we can store more, but the underlying machinery of storage and recall must be the same. Likewise, it seemed unquestionable that our capacity to remember is genetic: that our memories, although poorly developed when we are born, strengthen with the gradual maturing of our brains.
More recently, however, researchers have begun dividing human memory along the fault line of language to produce a quite different picture. It still includes a core genetic capacity shared with animals – the ability to recognise and associate – but on top of this is the learnt, language-based skill we know as recollection.
The human mind is driven by an inner world of thoughts, plans and intentions. But the awareness of a typical animal mind seems, as far as anyone can tell, to be locked into the present, driven purely by the flow of external events. Animals certainly have a memory, but it is only a direct, associative memory that is mobilised to make sense of events as they are occurring. There is little evidence that cats have an internal mechanism for bringing past experiences back to mind independently of what is happening around them. It is with self-addressed speech that humans discovered just such a trigger mechanism.
At one level, the power of language is self-evident. Though spoken words are mere noises – puffs of air – we learn to associate them with specific sets of ideas, so the act of saying or hearing a word, or reading a word in print, will unlock a wealth of images, associations and experiences in our heads. Hearing words such as ‘alligator’ or ‘hovercraft’ will sting our brains into action, creating a surrogate experience that is almost as good as having an actual alligator or hovercraft before our eyes. Words are like handles that haul ideas through the biological ‘display area’ of consciousness.
But it is at the next level, the question of how we use our inner voices to organise higher mental activities such as remembering, reflecting and planning, where the questions start.
Vygotsky pioneered a developmental approach which some researchers are now rediscovering. Vygotsky observed that children go through a phase between the ages of two and seven when they spend a lot of time talking aloud to themselves. Closer analysis showed that what the children were doing was rehearsing the habits of planning and organising that they would later internalise as inner speech. A boy sitting down at a playschool art table, for example, might be heard to say: I want to draw something. Let’s see. I need a big piece of paper. I want to draw a cat.’
Vygotsky tried to show how similar use of self-addressed speech underpinned the human ability to recollect. To begin with, Vygotsky argued that the process of learning a vocabulary imposes an abstract structure on our memories. As a child masters words such as ‘cat’, ‘draw’ and ‘paper’, it creates a series of culturally defined categories into which new experiences can be assimilated. At first, a child may call every furry animal a ‘kittie’, but eventually the word will come to stand for a more sharply defined set of images and ideas.
Developmental psychologists have found many examples of how children’s memories come to be linguistically organised, but perhaps the most obvious is in the act of drawing. When children of kindergarten age are asked to draw something like a house, their pictures are surprisingly stereotyped – a square box with two windows, a door in the centre, a triangle for the roof and a chimney blowing smoke. What the children put down on paper is not a remembered image of an actual building but a word-based representation that includes elements such as windows, doors, curtains and chimneys, which they have learnt to associate with the concept of a house. It is only with a lot more training that children can be taught to draw simply ‘what they see’.
But Vygotsky went further, saying that language not only gives our memories a culturally based order, it is also the mechanism by which we call memories back to mind. Through skilled self-questioning, we prod old memories free. Most people are aware of the kind of effort they need to make to flush out a recollection. For example, people asked to recall what they had had for breakfast the previous day normally report going through a similar process of inner questioning and suggestion. They may try thinking of the usual kinds of things they have for breakfast, saying to themselves something like: ‘Coffee? Cornflakes?. . .no, I was out of milk. Toast?. . .it was toast!’ The image-stimulating power of words would be used to set up a series of ‘target’ experiences, then when their thoughts strayed close enough to the dormant memory trace, the basic knowledge-mobilising powers of the brain would take over and there would be an confirming flash of recognition, a mental ‘aha!’ telling them they were correct.
Vygotsky’s circumstances did not allow him to gather anything more than sketchy evidence of this inner use of speech. But during the 1980s, a number of researchers tried to probe the kind of ‘verbal protocols’ people might use by asking subjects to think aloud as they carried out a memory task. One classic experiment involved people trying to recall the names of all their classmates from their teenage schooldays. With as many as 600 classmates to be remembered, some of the tape-recorded sessions went on for a total of ten hours.
The recordings showed the mix of self-prompting and confirmation that might be expected from a process of word-based suggestions leading to answering flashes of recognition and association. A typical report went: ‘It’s like I want to think of, sort of, prototypical situations and then sort of examine the people that were involved in those. And things like PE class, where there was. . .ah. . .Gary Booth. Umm, and Karl Brist, were sort of. . .we always ended up in the same PE classes, for some reason. Umm. . .I can think of things like dances. I guess then I usually think of. . .of girls. (chuckle)’
The developmental approach derived from Vygotsky’s work represents the most direct attack on traditional reductionist models of memory and the mind. But by the late 1980s others had begun to arrive at similar conclusion from entirely different starting points in the fields of sociology and anthropology.
Social scientists have, of course, always seen culture as a shaper of human attitudes and habits of thought. They have had their own inspirational figures in the anthropologist George Herbert Mead, the linguist Benjamin Whorf and the philosopher Ludwig Wittgenstein. But it is only recently that they have pushed the argument further and begun to analyse the role that language and society might play in moulding mental abilities.
One flourishing school, known as ‘social constructionism’, compares ways of thought in different societies and at different times in history to show how language acts as a ‘genetic code’ for the beliefs and customs of a culture. This approach has had a particular impact in the field of human emotions, where anthropologists have been able to show that higher feelings, such as loyalty, righteousness and even romantic love, are really culturally invented attitudes. A word is used to stand for a set of ideas and characteristic physiological states and behaviours. In this view, a higher emotion is not a pure mental state but something more akin to a script we have internalised and learnt to act out.
EXTRATERRESTRIAL THINKING
Recently, psychologists have extended the social constructionist approach into memory research. David Middleton and Derek Edwards of Loughborough University have adopted the technique of discourse analysis, in which samples of everyday conversation are put under the microscope to see how social situations may control people’s efforts at recall. One typical discourse analysis experiment might involve recording a group of people discussing the film ET and observing how a collective version of events gradually emerges as ideas and associations are bounced back and forth.
But while developmental and social approaches to memory have blossomed over the past few years, suggesting that a fundamental change may be afoot, the mainstream of psychology is still firmly reductionist in outlook. Most cognitive psychologists remain wedded to the assumption that recollection and recognition are simply different parts of the same biological system – a system which should eventually be reducible to a collection of neural circuits or computational modules.
The doyen of memory researchers, Alan Baddeley of the Medical Research Council’s Applied Psychology Unit in Cambridge, summed it up when he recently dismissed the discourse analysis approach: ‘A great deal of the study of memory is precisely concerned with avoiding confounding memory with the language in which a particular recollection is phrased’.
Given this outlook, it is not surprising that cognitive psychologists tend to cloak social and language-based aspects of the human mind in mechanistic jargon. For example, when describing the act of recollection, they prefer to talk about ‘cue generation’ under the guidance of a ‘central executive’, with information being held in ‘articulatory loops’ and ‘visuo-spatial scratchpads’ – all terms with the reassuring ring of being computational processes.
Turning to the question of consciousness itself, what emerges from taking a dual approach? Probably the most important change is that it lifts a huge weight from the shoulders of neurology. The old habit of treating the mind as a closed biological system has led us to think of self-awareness as being an inherent property of consciousness. But the ability to think about what is going on in one’s own mind is a trick of language-controlled memory. It is part of what distinguishes human consciousness from the animal mind.
In contrast to animals, humans can use inner speech to call to mind previous states of awareness; previous thoughts, feelings and actions. We can live the moment, then relive it, creating the eerie illusion that consciousness is also conscious of itself. But even in humans, consciousness need not involve self-awareness. This becomes apparent when we do something so fast and reflexive, such as hitting a tennis volley or catching a falling glass, that we do not have the usual time to both act and review the act as it is unfolding.
What follows is that, contrary to common assumption, humans are not automatically self-aware. We have to learn the trick of reflection – and undoubtedly we learn it with varying degrees of success, some people becoming more skilful in, or devoted to, the ways of introspection. Furthermore, if we want to understand how self-awareness is formed in children, we have to look to linguistics and social psychology.
It is already clear from the work of Vygotsky, Mead and Whorf that much of the necessary training is implicit in our culture. The very fact that children need to learn to handle words like ‘I’ and ‘you’ in conversation forces them into a realisation of their own existence. Society’s subsequent demand that they learn to become self-directed individuals, able to give a reasoned account of their actions, places further pressure to develop a habit of introspection and a sense of self.
Once the concept of consciousness has been stripped of the many puzzling qualities we normally associate with it, science is freed to chase a much more specific target. This makes consciousness far simpler to explain. Instead of having to account for the elaborate superstructure of the higher mind, including such language-based constructs as reflective awareness and the controlling ego, neurology only has to consider the more primitive animal awareness. Consciousness then boils down to nothing more than a single, core brain process – the mapping of sensations which creates the primary field of experience, followed by the recognition and association processes that make this field seem meaningful and understood.
The first stage of the process, the mapping of a field of sensations, is already reasonably well documented. The development of medical brain scanners which can ‘photograph’ patterns of neural activity and blood flow as they sweep across the brain has revealed in detail how the images striking our eyes are re-created as matching patterns of nerves firing in the brain’s visual centres. A web of connections is tugged into existence, forming a living model of the world inside our heads.
It is the next stage of the process which has been rather neglected – the forging of a link between these fleeting sensory maps and the stored memories needed to make sense of them. An image of a cow or a car is just a clutter of shapes and colours until viewed against the backdrop of experience. This means that many times a second, the brain must be finding the connection between each newly arrived image and an answering patch of memory. It is out of this rapid sequence of matches that a coherent stream of consciousness emerges.
With consciousness pared down to a simple cycle of activity – a cascade of mapping, recognition and association processes – it begins to look like the orderly flow of neural events that reductionist science always believed it to be. Neuroscientists have already dubbed the 1990s the Decade of the Brain because of the promise of the discoveries to be made with technologies such as medical brain scanners.
Yet there is a big difference between finding patterns of brain activity and interpreting them. The mind sciences are as much in need of a conceptual revolution as a technological one. Encouragingly, the surge of interest in the writings of Vygotsky – and others who are looking at the mind as part biological machine, part cultural habit – suggests that such a change may now be in the air.
John McCrone is the author of The Ape That Spoke: Language and the Evolution of the Mind (Picador, 1991) and The Myth of Irrationality: The Science of the Mind from Plato to Star Trek (Macmillan, 1993). He is currently writing a book on the biology of consciousness.
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Circular process or circular argument?
Two serious difficulties beset the argument that humans use inner speech to shape thought. First, the position seems circular: how could we know what words to use to create a thought unless we had already thought about what to say? For instance, how could we decide to say the word ‘dog’ to conjure up a mental image of a dog unless the notion of a dog was already in our minds? The second puzzle is why a stroke can rob someone of the ability to speak without apparently affecting their ability to think?
Part of the answer to the accusation of making a circular argument is that the process we are describing is itself circular. What we call thought is a loose feedback cycle in which words prompt associations, and associations in turn prompt further words. Some association must have led us to the word ‘dog’ in the first place. Then having called up a dog image, further associations will lead us to the next words we say. If words and images often seem to arrive together in our minds in a tangle, this is just because the cycle of thought moves so quickly it becomes a blur.
But the full story must be a lot more complex. Much of the interaction between language and the natural powers of the brain takes place at a deeper level, in ‘out-of-sight’ subconscious processes, and what seems conscious and deliberate about the process is just the tip of the iceberg.
This ties in with the second puzzle. It is true that many stroke victims can think but not speak, but the reverse is also true. The Soviet neurologist Alexander Luria – Lev Vygotsky’s closest colleague – described many patients with damage to their frontal lobes who could repeat words spoken to them but could not generate any conversation of their own. These patients would lie immobile on their beds, apparently robbed of all thought or will. Luria concluded that the frontal lobes must be where the planning of a speech act begins and that it is only when this part of the brain is knocked out that inner speech – and hence thought – is paralysed.
