Date: Fri, 13 Sep 2002 22:24:18 -0500 (EST) From: Robert Port Subject: Psycholinguistics/Neurolinguistics: Marantz, Miyashita and O'Neil (eds.)
Marantz, Alec, Yasushi Miyashita and Wayne O'Neil (eds.) "Image, Language, Brain: Papers from the First Mind Articulation Project Symposium." (MIT Press; Cambridge Mass, 2000). 272 pages. With introduction by the three editors, 12 chapters. Part I. Language and Brain. Part II. Image and Brain.
Robert Port, Departments of Linguistics, Cognitive Science and Computer Science, Indiana University.
This book is based on a conference held in 1998 in Tokyo. The purpose of the meeting was to "examine recent attempts to unify linguistic theory and brain science that have grown out of the increasing awareness that a proper understanding of language in the brain must reflect the steady advances in linguistic theory of the past forty years" and to "integrate linguistics and brain science in a way that has been attempted in the study of the visual system."
This collection of research reviews provides an excellent introduction to the area, although some previous background in neuroscience would be essential to evaluate and integrate the arguments. The volume contains good tutorial material on some behavioral research techniques and recent neuroimaging methods. Linguists with an interest in neuroscience will find many provocative ideas in these chapters. At this point, quite a bit is known about what regions of the brain are active for various components of linguistic processing - both for production and perception of speech. Although there is certainly no concensus view emerging from these papers, there is certainly a great deal of concrete and stimulating evidence about cognitive skills and the brain.
Chapter 1. N. Chomsky `Linguistics and the Brain'. This seems to be the first serious defense of his early views on the "language acquisition device" in several decades. Suffice it to say, he gives up nothing. He begins by taunting neuroscientists for the overly optimistic views of some on how close we are to understanding brain functions like language and he scoffs at talk of "emergence" as though it were some deep new insight when, in his view, the term is just a mask for our continuing ignorance (and, characteristically, that it is an idea that was anticipated in scientific discussions during the 18th century).
Chomsky's basic argument is that cognitive science is in the same position with respect to biology and physiology as chemistry was to physics until almost the mid-20th century. In the 18th century, he says, chemists abandoned all attempts to reduce chemistry to physical principles and simply began cataloguing phenomena and organizing them as best they could -- without claiming to even be studying anything real. Unification of the theory of chemistry to physics didn't come until very recently after physics was itself radically restructured (by quantum theory) in a way that allowed chemistry to be unified with it. By analogy, linguists should just plow ahead without worrying whether linguistic theories can find physiological interpretation. In due time, it is brain science that will figure out how to accept and incorporate the results of modern linguistics (he hopes).
Chapter 2. "Cognitive neuroscience of speech processing," by David Poeppel and Alec Marantz. This chapter offers an excellent tutorial on the logic and relative strengths of the four new noninvasive techniques discussed in many later chapters: functional magnetic resonance imaging (fMRI), magneto-encephalography (MEG), electroencephalography (EEG) and positron emission tomography (PET).
Chapter 3. "How infants acquire language: Some preliminary observations," by Jacques Mehler, Anne Christophe and Frank Ramus. The authors review many Chomsky-inspired ideas about language acquisition, eg, regarding "language modules", "the language organ", the acquisition of "parameters", etc and find his ideas to be generally supportable at least when compared to the earlier learning-based views. Still, they acknowledge that there is clear evidence that statistical properties of the presented corpus are also employed by language-learning infants.
Chapter 4. "The speaking mind/brain: Where do spoken words come from?" by W. Levelt and P. Indefrey. Noting that "nothing is more useful in cognitive neuroscience than a well-founded processing theory" the authors attempt to break down various language tasks (eg, picture naming, word reading, word repetition, etc.) into hypothesized component processes. Then they do meta-analysis on the published literature that use the various brain imaging techniques to infer what regions of cortex are uniquely involved in each component process. The outcome is a set of pictures of cerebral cortex showing which (rather large) regions should be implicated in which processes. A later article by Frackowiak, however, offers a word of caution regarding this method of drawing inferences from such addition and subtraction of cognitive functions: he notes that that these tasks have many kinds of interactions. Just because, say, one asks the subject only to pronounce a word doesn't mean that they do not also process the meaning.
Chapter 5. "The dependency locality theory: A distance-based theory of linguistic complexity," by E. Gibson. The author reviews earlier attempts to explain why some syntactic constructions (eg, center-embedding as in "The reporter who the senator who John met attacked disliked the editor") are much more difficult than others (eg, "The senator that John met disliked the reporter who attacked the editor" and even "The reporter who the senator I met attacked disliked the editor"). His scoring mechanism for degree of difficulty of sentences based on his dependency-locality model is supported by experimentally obtained measures of "comprehension time" for a set of sentences.
Chapter 6. "The neuronal dynamics of auditory language comprehension" by A. Friederici. This work makes comparisons of brain response for normal German sentences, "syntactic prose" (analogous to "All wimsy were the borogroves" that are easy to parse but have mostly nonsense vocabulary), word lists (using the vocabulary of the normal sentences) and pseudo word lists (like "were, borogroves, wimsy, all," etc). Both fMRI (for location) and event-related potentials (for time functions) are obtained to allow interpretation of brain processing.
Chapter 7. "Neural control of cognition and language" by Masao Ito. This eminent neuroscientist gives us his bigpicture view of cognition in terms of control theory (using notions like input, controller, control object, feedback, etc). He proposes that linguistic behavior and abstract "verbal thought" can be insightfully understood in these terms especially by integrating recent discoveries about the essential role of the cerebellum in language and general cognition. The most striking novel claim is that " mental activities are analogous to movements" (p. 158). The cerebellum, he says, provides internal models for control, both for movement and for verbal thinking, neither of which depends on sensory feedback.
Chapter 8. "Imaging neuroscience: System-level studies of the physiology and anatomy of human cognition", by R Frackowiak. This readable paper reviews results on visual and motor imaging and the corresponding neural maps obtained in recent years using the four main noninvasive techniques. Then he comments on how these ideas might apply to cognitive processes and language.
Chapter 9. "Central control of voluntary movement as studied by multidisciplinary noninvasive approaches," by Hiroshi Shibasaki. A review of work investigating the commands (or "will") to execute gross bodily motions and gaits and to stop these motions. The question is to find just where this command occurs and when it occurs relative to movement onset. Different noninvasive techniques are appropriate for different aspects of the question.
Chapter 10. "Neuromagnetic inverse modeling: Application of eigenstructure-based approaches to extracting cortical activities from MEG data," by Kensuke Sekihara, David Poeppel, Alec Marantz and Yasushi Miyashita. Given measurements from various places on the skull, how can the precise 3D location of an event within the skull be determined? This paper reviews mathematical aspects of this issue and presents algorithms to do the job.
Chapter 11. "Competitive mechanisms subserve selective visual attention" by J. Reynolds and Robert Desimone. This paper reviews studies by Desimone and colleagues investigating the neural mechanisms of visual attention when monkeys see one or several visual targets at the same time. After presenting data supporting their "biased competition" model, they present a simple neural network and its dynamical equations that can account for the experimental results.
Chapter 12. "Origin of visual imagery: Its neurophysiological basis," by Yasushi Miyashita. This presents studies of the neural basis of the "depictive internal representations" (that is, roughly, visual images) used for solving memory tasks by macaques using methods employing single-unit recordings (that is, with electrodes inserted in single cells) from the inferotemporal cortex and other techniques.
CONCLUSIONS Every paper in this book is good -- not a dud anywhere. The editors endeavored to provide enough background material (and probably enough editorial intervention with the chapter authors) that the book is relatively accessible to a broad scientific audience. It may still be a challenge to the typical linguist, but I recommend it for those interested in the question of how to approach the neural basis of language. Although Chomsky's chapter seems to suggest that linguists need not concern themselves much with the matters presented in the rest of the book, my view is that Chomsky is wrong. What we need is not major revisions in biology to allow linguistics to be absorbed as is, but rather major revisions in linguistics to make it fit with biology.
ABOUT THE REVIEWER:
About the reviewer Robert Port is a phonetician oriented toward cognitive science. He has a PhD in linguistics from University of Connecticut and a Masters in Linguistics from Columbia. His main research area is in the temporal aspects of speech. In recent research, he has been concerned with the tendency toward periodic patterning of repeated phrases and the evidence this offers supporting a role for dynamical systems in speech production and perception. He edited "Mind as Motion: Explorations in the Dynamics of Cognition" (MITP, 1995) with Tim van Gelder.