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The current fMRI adaptation study sought to elucidate the dimensions of syntactic complexity and their underlying neural substrates. For the first time with fMRI, we investigated repetition suppression (ie, fMRI adaptation) for two orthogonal dimensions of sentence complexity: embedding position (right-branching vs center-embedding) and movement type (subject vs object). Two novel results were obtained: First, we found syntactic adaptation in Broca's area and second, this adaptation was structured. Anterior Broca's area (BA 45) selectively adapted to movement type, while posterior Broca's area (BA 44) demonstrated adaptation to both movement type and embedding position (as did left posterior superior temporal gyrus and right inferior precentral sulcus). The functional distinction within Broca's area is critical not only to an understanding of the functional neuroanatomy of language, but also to theoretical accounts of syntactic complexity, demonstrating its multi-dimensional nature. These results implicate that during syntactic comprehension, a large network of areas is engaged, but that only anterior Broca's area is selective to syntactic movement.It is almost universally agreed that the linguistic comprehension function of some language regions of the brain is related to syntactic complexity. Less clear is the definition of this functional notion, even though its elucidation is crucial for an understanding of the functions of these brain regions -a long debated issue, especially concerning Broca's area Caplan et al., 2000;Friederici et al., 2006;Grodzinsky, 2000). In this paper, we report a highly structured, tightly controlled and counterbalanced fMRI adaptation experiment, that helps elucidating this notion by considering (some of) its component parts, and localizing them in distinct cerebral loci. Our results refine our understanding of the functional anatomy of processes underlying syntactic complexity, and furthermore support the move to make functional subdivisions within Broca's area (Makuuchi et al., 2009).Our investigation uses an array of complex sentences constructed around two orthogonal and independently motivated complexity factors: word-order canonicity (and its close relative, syntactic Movement in its varied instantiations) and place of embedding. Our method, fMRI adaptation, is based on the observation that a stimulus property, once repeated, yields a suppressed signal, and so helps to identify such properties that a particular Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeuroimage. Author manuscript; avai...

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Let (V, (·, ·)) be a pseudo-Euclidean vector space and S an irreducible Cℓ(V )-module. An extended translation algebra is a graded Lie algebra m = m−2 + m−1 = V + S with bracket given by ([s, t], v) = b(v · s, t) for some nondegenerate so(V )-invariant reflexive bilinear form b on S. An extended Poincaré structure on a manifold M is a regular distribution D of depth 2 whose Levi form Lx : Dx ∧ Dx → TxM/Dx at any point x ∈ M is identifiable with the bracket [·, ·] : S ∧ S → V of a fixed extended translation algebra m. The classification of the standard maximally homogeneous manifolds with an extended Poincaré structure is given, in terms of Tanaka prolongations of extended translation algebras and of appropriate gradations of real simple Lie algebras.2000 Mathematics Subject Classification. 53C30, 58A30, 53C27, 53C80.

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Abstract:We recover the classification of the maximally supersymmetric bosonic backgrounds of 11-dimensional supergravity by Lie algebraic means. We classify all filtered deformations of the Z-graded subalgebraswhich differ only in zero degree, that is h 0 ⊂ g 0 and h j = g j for j < 0. Aside from the Poincaré superalgebra itself and its Z-graded subalgebras, there are only three other Lie superalgebras, which are the symmetry superalgebras of the non-flat maximally supersymmetric backgrounds. In passing we identify the gravitino variation with (a component of) a Spencer cocycle.