=Paper=
{{Paper
|id=Vol-1419/section0006
|storemode=property
|title=None
|pdfUrl=https://ceur-ws.org/Vol-1419/section0006.pdf
|volume=Vol-1419
}}
==None==
https://ceur-ws.org/Vol-1419/section0006.pdf
Towards a Neurobiology of Language
Chairperson
Steven L. Small (small@uci.edu)
Departments of Neurology, Neurobiology & Behavior, and Cognitive Sciences
University of California, Irvine, Irvine, California USA
Speakers
Ferdinand Binkofski (fbinkofski@ukaachen.de)
Department of Neurology
Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen, Aachen, Germany
Steven L. Small (small@uci.edu)
Departments of Neurology, Neurobiology & Behavior, and Cognitive Sciences
University of California, Irvine, Irvine, California USA
Uri Hasson (uhasson@gmail.com)
Center for Mind/Brain Sciences (CIMeC) and Department of Psychology and Cognitive Science
University of Trento, Mattarello (TN), Italy
Jeremy Skipper (jskipper@lab-lab.org)
Department of Experimental Psychology, Institute for Multimodal Communication
University College London, London, England
Mikkel Wallentin (mikkel@cfin.dk)
Center of Functionally Integrative Neuroscience
Aarhus University Hospital, Aarhus, Denmark
The advent and/or improvement of high resolution brain Dorsal and ventral processing streams in the
imaging methods over the past two decades – both spatial and
temporal – has led to the emergence of an anatomically and human brain
physiologically robust human neuroscience. In no area has this
been more evident than in the study of human language. A Ferdinand Binkofski
recent congress on the Neurobiology of Language attracted over
500 participants. Many – but not all – researchers in this field
take the view that language processing in the brain is The distinction between dorsal and ventral processing
implemented by many interacting sensory, motor, and streams has been elaborated substantially in recent years,
conceptual networks that are not specific to language, but spurred by two developments: (1) First is a more detailed
evolved to support many critical features of human cognition, description of the multiple neural circuits connecting the
including contextual expectation, statistical inference, sequence frontal, temporal, and parietal cortices; and (2) Second are a
processing, error detection and correction, and related
computational basics. The neural systems that underlie these number of behavioral observations that the classic "two
computations appear to incorporate a large number of anterior- visual systems" hypothesis needs refinement to
posterior brain connections along dorsal and ventral “streams”. accommodate additional assumptions. The notion that there
Although these streams each include many individual is a single dorsal stream that is specialized for "where" or
connections, and contribute to many different functions, some "how" actions and a single ventral stream for "what"
gross functional generalities can be articulated. In this
Symposium, we introduce the anatomy of these streams, and knowledge cannot account for two prominent disorders of
then describe several models and/or cognitive functions that action, limb apraxia and optic ataxia, that represent a
support language processing in dorsal and ventral brain double dissociation in terms of the types of actions that are
networks. preserved and impaired. A growing body of evidence
suggests that there are at least two distinct dorsal routes in
2
the human brain, which we characterize as the "Grasp" and Statistical regularities in input: The basis of
"Use" systems. Both of these may be differentiated from the neural encodings for language
ventral route in terms of neuroanatomic localization,
representational specificity, and time course of information Uri Hasson
processing. In this talk, we discuss the anatomy and
physiology of the dorsal and ventral streams for vision and The capacity to code for statistical features of language is
action, and relate them to the analogous streams for thought to enable language learning, assist online word
audition, speech, and language. segmentation, and form a basis for prediction of
subsequent speech input. How does the brain code for the
statistical structure of the language stream? I will present
Neurobiological roots of language in primate recent neuroimaging data addressing this question, and
audition: Common computational properties focus on three issues: a) Is there a domain general system
sensitive to structure in both language-like and non-
Steven L. Small language like inputs? b) Are there separate systems
sensitive to different types of statistical information, e.g.,
Neurobiologically plausible models of human brain marginal frequency vs. transition probability? and c) Are
function are typically based on detailed animal models. different forms of statistical learning engaged depending
However, while the applicability of this modeling strategy on whether the language tokens are novel or familiar? The
is widely accepted for domains such as vision or audition, answers to these questions (no, yes, and yes) suggest the
its transferability to human language is considerably more existence of distributed, domain-specific systems for
controversial. The reason for this perspective – particularly encoding statistical structure, with separate brain systems
at the level of sentences and above – relates to complex coding for different statistical aspects of the stimulus.
computational properties of human grammars and their (Research supported by ERC starting grant NeuroInt)
purported specificity to our species. It is generally accepted
that human speech and language processing is supported by
a cortical dorsal-ventral streams architecture that shares Context is all: There is no fixed organization of
many anatomical characteristics with the extended auditory language and the brain
system of nonhuman primates. A postero-dorsal stream
connects AC to the posterior and dorsal part of inferior Jeremy Skipper
frontal cortex (IFC) (Brodmann area [BA] 44) via posterior
superior temporal (pST) cortex, inferior parietal lobule Is there a ‘center of speech’ in the brain? It is generally
(IPL), and premotor cortex (PMC, whereas an antero- (though perhaps implicitly) assumed that there is. In
ventral stream traverses anterior superior temporal cortex contrast, I argue that there is no core, i.e., fixed region, set
(aST) to terminate in more anterior and ventral parts of the of regions, or (dual) "streams" supporting the
inferior frontal gyrus (BA 45). Dual–stream models of organization of language and the brain. I suggest that the
sentence processing typically assume that the neural illusion that there is some core is created by: 1) the wiring
circuitry of nonhuman primates is insufficient to support of the brain, 2) the methods and statistics used in
sentence comprehension because of a fundamental neuroimaging and 3) the fact that we have not observed
difference in its computational architecture that is not the brain during natural language use. Supporting this
simply a matter of degree. They thus posit uniquely human argument, I show that the same word can have a very
additions to this circuitry in the dorsal stream, which are different whole brain organization as a function of the
assumed to have evolved late from a phylogenetic type of context that accompanies that word. Context
perspective and to mature late from an ontogenetic includes both that which is present (e.g., observable
perspective. In this talk, we suggest that the nonhuman speech associated gestures) and that which has been
primate dorsal and ventral auditory streams have the previously experienced (e.g., music, lip movements, and
necessary mechanistic components to perform sentence and written text repeatedly encountered in the past). I also
discourse processing, even though the system lacks the show that, even in brain regions where activity might be
necessary quantitative scale to support language. expected to be comparable for a word heard in different
(Research supported by the National Institutes of Health of the
contexts, e.g., auditory cortex, it is not. I argue from these
USA)
results that, rather than being organized around linguistic
information per se, language and the brain is organized
around context. This is because context is necessary for
speech perception and language comprehension to occur.
Because the context associated with natural language use
3
is ever changing, so to will the many brain networks that
comprise the organization of language and the brain be
dynamic.
Context predicts word order processing in
Broca's region
Mikkel Wallentin
While famous for its role in language processing, the actual
function of the left inferior frontal gyrus (L-IFG) is still
highly disputed. In terms of dual stream models, it has
recently been argued to be part of the dorsal stream for
speech, whereas it has also traditionally been considered as
part of the extended ventral visual stream. A number of
language processing studies have linked the region to the
processing of syntactic structure. Still, there is little
agreement when it comes to defining why linguistic
structures differ in their effects on the L-IFG. In a number
of languages, the processing of object-initial sentences
affects the L-IFG more than the processing of subject-initial
ones, but frequency and distribution differences may act as
confounding variables. Syntactically complex structures
(like the object-initial construction in Danish) are often less
frequent and only viable in certain contexts. With this
confound in mind, the L-IFG activation may be sensitive to
other variables than a syntax manipulation on its own. This
talk investigates the effect of a pragmatically appropriate
context on the processing of subject-initial and object-initial
clauses with the IFG. We find that Danish object-initial
clauses yield a higher BOLD response in L-IFG, but we
also find an interaction between appropriateness of context
and word order. Given an appropriate context, the L-IFG
activation drops remarkably for object-initial clauses. This
interaction overlaps with traditional syntax areas in the IFG.
Further, an acceptability study shows that, given
appropriate contexts, object-initial clauses are considered
more appropriate than subject-initial clauses. The increased
L-IFG activation for processing object-initial clauses
without a supportive context may be interpreted as
reflecting either reinterpretation or the recipients' failure to
correctly predict word order from contextual cues. These
findings are discussed in relation to the dual stream models.
4