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VI
Preface
By now, virtually everyone agrees that the scientific explanation for human language and cognition will be based on our bodies, brains, and experiences…
Try expressing to yourself what you know about how your own thoughts work. How do our brains compute our minds? When I ask students to write a page on this question, most of the students express mystification. Even people who know a great deal about neuroscience, psychology, linguistics, philosophy, and artificial intelligence often have no clear idea of how the findings of these fields could combine to yield even a preliminary understanding of how language is embodied in us.
VII
This book proposes to begin integrating current insights from many disciplines into a coherent neural theory of language. It might seem that no such effort is needed. Isn't language obviously a function of our brains - what else could it be? Certainly other human abilities such as motor control, hearing, and especially vision have been studied as a neural systems for many decades. But language is still often treated as an abstract symbol system not particularly tied to human brains or experience.
A great deal of permanent value has been learned from formal studies of language, but it is surprising that the notion of disembodied language persists. This is partly historical artefact, but it also arises from the fact that other animals share visual and motor abilities but not our language skills. Much of the progress in neural theories of vision and motor control have come from invasive animal experiments that are thankfully prohibited on people. Until recently, very little has been known about how our brains process language.
Currently no one knows the details of our words and sentences are processed in the brain, and there is no known methodology for finding out. Many scientists believe it is premature to formulate explicit theories linking language to a neural computation. Even theoreticians are usually content with suggestive models, which can't actually be right, but to suggest interesting experiments. However, the cognitive sciences reveal a great deal about how our brains produce language and thought. And we have a long and productive tradition, going back at least to the Greek atomic theories of matter, of postulating „bridging theories“ in advance of the detailed evidence.
In contemporary science, it is not unusual to have quite extensive knowledge at both ends of a causal chain and to build and test theories to explicate the bridging links... Much of the molecular biology is concerned with how genetic material yields the various proteins and resultant organisms. Higher levels of biology also try to develop bridging theories. We can see the search for a neural theory of language as one such attempt, albeit an unusually ambitious one. These bridging theories are often developed as computer simulations, and this book follows this tradition.
I treat the mind is a biological question - language and thought adaptions that extend abilities we share with other animals. For well over a century, this has been the standard scientific approach to other mental capacities such as vision and motor control. But language and thought, even now, are usually studied as abstract formal systems that just happened to be implemented in our brains... We pursue four questions that must be asked of any biological ability:
How does it work?
How does it improve fitness?
How does it develop and adapt?
How did it evolve?
The first three of these questions are covered in considerable detail. The origins of language are still largely unknown and discussed briefly in chapter 26.
There is a sufficiently large gap between brain and language to contain ecological niches for many theories, especially if their proponents are satisfied to ignore inconvenient findings. Understanding language and thought requires combining findings from biology, computer science, linguistics, and psychology. The theory that seems perfectly adequate from one perspective may contradict what is known in another field. Problems that seem intractable than one discipline might be quite approachable from a different direction. Taking all the constraints seriously is the only way to get it right.
But this requires us to understand the essential ideas from several quite different scientific domains. In any of these fields, keeping up with technical advances and doing original work are extremely demanding pursuits and require focused effort. There are some endeavours at the boundaries between subfields, but very little scientific work that attempts to encompass the full range needed for our task. I will need to synthesise a bridging theory from separate fields, all of which have their focus elsewhere. My approach is to pick out key findings and theories from various disciplines and show how, in combination, they constrain the possible bridging theories of language to a narrow family of possibilities.
Each discussion is an oversimplification of some research field, often involving thousands of active investigators, and thus is inherently incomplete. The usual references suggest more detailed discussions of various points, but these are most useful as keywords for search engines.
While we are far from having a complete neural theory of language, enormous scientific advances have occurred in all the relevant fields. Taken together, these developments provide a framework in which everything we know fits together nicely. The goal of this book is simple: I would like you, at the end, to say,This all makes sense. It could explain how people understand language. I will make no attempt to convince you other theories are wrong - in fact, I assume that most of them are partially right. The book can be seen as a part of a general effort to construct a Unified Cognitive Science that can guide the effort to understand our brains and minds. I tried to present a story here that is consistent with all the existing scientific data and that also seems plausible to you as a description of your own mind.
Except for one thing. One part of our mental life is still scientifically inexplicable - subjective experience. Why do we experience everything in the way we do?
The pleasure of beauty, the pain of disappointment, and even the awareness of being alive…these do not feel like they are reducible to neural firings and chemical reactions. Almost everyone believes that his or her own personal experience has a quality that goes beyond what this book, and science in general, can describe. If I had anything technical to say about subjective experience, it would be the highlight of the book, to say the least.
People use terms like personal experience, subjective experience, and phenomenology to label this idea. Philosophers have coined a technical term, qualia, to refer to these phenomena that are currently beyond scientific explanation... Aside from a brief discussion in chapter 26 this book focuses on what can be learnt from studying the psychological and behavioural correlates of experience - that is, what can be measured and modelled objectively.
My undertaking of this quixotic enterprise came as the result of a year of explicit soul-searching around the time of my fortieth birthday. I had the good luck of entering the field of computer science in its infancy, and I believe this gave me the opportunity to move in almost any direction, exploiting inside centre information processing not available to previous generations. My long-term interests in language and the brain and work on the various computer systems including some of the earliest robots, led me to focus on the question that I just ask you - How does the brain compute the mind?
Feldman
Cognitive Linguistics
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