Neuroscience Colloquia, New York University
Additional Information, Spring 1998

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Speaker: Elizabeth Bates
Title: Brain and Language in Children and Adults
Abstract: The idea that the human brain contains a specialized organ for language has been with us for at least 200 years, from Franz Gall's theory of phrenology to Chomsky's Universal Grammar and Fodor's mental modules. It is generally supposed that this organ is (a) innate, (b) dedicated exclusively to the specific operations required for language (i.e. the language organ is domain-specific), and (c) localized to well-defined regions of the left hemisphere. In this presentation, I will review evidence from language outcomes in children and adults with focal brain injury supporting an entirely different view, in which brain organization for language (a) emerges across the course of development, (b) based on regional differences in information processing that are NOT specific to language, and (c) is distributed across multiple regions, in both hemispheres, in patterns that change dynamically across the period in which language is acquired, permitting altenative forms of organization to emerge in children with congenital injuries. This dynamic view of brain organization for language is compatible with findings from developmental neurobiology emphasizing plasticity and activity dependence in cortical development.
Related
articles:
  • Bates, E., & Goodman, J. On the inseparability of grammar and the lexicon: Evidence from acquisition, aphasia and real-time processing. Language and Cognitive Processes, 1997, 12(5/6), 507-586.
  • Bates, E., Thal, D., Trauner, D., Fenson, J., Aram, D., Eisele, J., & Nass, R. From first words to grammar in children with focal brain injury. In D. Thal & J. Reilly, (Eds.). Special issue on Origins of Communication Disorders. Developmental Neuropsychology, 1997, 13(3), 447-476.vls
  • J. Elman, E. Bates, M. Johnson, A. Karmiloff-Smith, D. Parisi & K. Plunkett. Rethinking Innateness: A Connectionist Perspective on Development. MIT Press, 1996.
    • Speaker: Rafael Yuste
    Title: Dendritic Integration in Pyramidal Neurons
    Related
    articles:
  • Yuste, R. and Denk, W. (1995). Dendritic spines as basic functional units of neuronal integration. Nature 375: 682-684.
  • Cash, S. and Yuste, R. (1998). Input Summation by Cultured Pyramidal Neurons Is Linear and Position-Independent. J. Neurosci. 18(1), 10-15.
    • Speaker: Mriganka Sur
    Title: Rewiring cortex: Visual activity and cortical development
    Abstract: Our experiments address the question of whether, and how, the pattern of afferent activity during development influences the function of cortical circuits. Routing visual projections to the auditory pathway in ferrets leads to visual activation of the developing auditory cortex, causing auditory cortex to receive patterns of input activity very different from normal. Visual inputs respecify the microcircuitry within primary auditory cortex, creating orientation-specific responses and maps of visual space and orientation-selective cells. They appear to alter the perceptual identity of primary auditory cortex, so that its activation is identified with visual stimuli. At the same time, several features of the cortex remain unaltered. Patterns of afferent activity thus profoundly influence cortical function, but they do not write on a blank slate.
    Related
    articles:
  • Roe, A., Pallas, S.L., Kwon, Y.H. and Sur, M. (1992), Visual projections routed to the auditory pathway in ferrets: receptive fields of visual neurons in primary auditory cortex. J. Neurosci. 12(9), 3651-3664.
  • Angelucci, A., Clasca, F., Bricolo, E., Cramer, K., and Sur, M. (1997), Experimentally induced retinal projections to the ferret auditory thalamus: Development of clustered eye-specific patterns in a novel target. J. Neurosci. 17(6), 2040-2055.
    • Speaker: Darcy Kelley
    Title: What makes Xenopus tick? Generating male- and female-specific courtship songs
    Related
    articles:
  • Tobias, M.L.,Viswanathan, S. and Kelley, D.B. 1998 Rapping, a female receptive call, initiates male/female duets in the South African clawed frog, Proc. Natl. Acad. Sci., 95, (due out February, 4th issue of 1998).
  • Kelley, D 1997 Generating sexually differentiated songs Current Opinion in Neurobiology, 7, 839 - 843.
  • Ruel, T., Kelley, D. and Tobias, M. 1997. Facilitation at the sexually differentiated laryngeal synapse of Xenopus laevis, J. Comp. Physiol.,182, 35 - 42.
  • Kelley, D. 1996. Sexual differentiation in Xenopus laevis. In: The Biology of Xenopus, R.Tinsley and H. Kobel (Eds), Oxford University Press, Oxford, pp 143 - 176.
  • Tobias, M. and Kelley, D.B. 1995. Sexual differentiation and endocrine regulation of the laryngeal synapse in Xenopus laevis, J. Neurobiol., 28, 515 - 526.
  • Catz, D., Fischer, L. and Kelley, D. 1995 Androgen regulation of a laryngeal-specific myosin heavy chain isoform whose expression is sexually differentiated, Dev. Biol., 171, 448 - 457.
  • Fischer, L., Catz, D.and Kelley, D. 1995. Androgen-directed development of the Xenopus laevis larynx: control of androgen receptor expression and tissue differentiation, Dev. Biol., 170, 115 - 126.
  • Tobias, M., Kelley, D. and Ellisman, M. 1995. A sex difference in synaptic efficacy at the laryngeal neuromuscular junction of Xenopus laevis, J. Neurosci., 15, 1660 - 1668.
    • Speaker: Dan Margoliash
    Title: Functional organization and neural codes in the bird song system
    Abstract: This paper reviews the organization of the forebrain nuclei of the avian song system. Particular emphasis is placed on recent physiological recordings from awake behaving adult birds while they sing, call, and listen to broadcast of acoustic stimuli. The neurons in the descending motor pathway (HVc and RA) are organized in a hierarchical arrangement of temporal units of song production, with HVc neurons representing syllables and RA neurons representing notes. The nuclei Uva and NIf, which are afferent to HVc, may help organize syllables into larger units of vocalization. HVc and RA are also active during production of all calls. The patterns of activity associated with calls differ between learned calls and those that are innately-specified, and give insight into the interactions between the forebrain and midbrain during calling, as well as into the evolutionary origins of the song system. Neurons in area X, the first part of the anterior forebrain pathway leading from HVc to RA, are also active during singing. Many HVc neurons are also auditory, exhibiting selectivity for learned acoustic parameters of the individual bird=B9s own song (BOS). Similar auditory responses are also observed in RA and area X in anesthetized birds. In contrast to HVc, however, auditory responses in RA are very weak or absent in awake birds under our experimental paradigm, but are uncovered when birds are anesthetized. Thus, the sensory roles of both pathways beyond HVc in adult birds is under review. In particular, theories hypothesizing a role for the descending motor pathway (RA and below) in adult song perception do not appear to obtain. The data also suggest that the anterior forebrain pathway has a greater motor role than previously considered. We suggest that a major role of the anterior forebrain pathway is to resolve the timing mismatch between motor program readout and sensory feedback, thereby facilitating motor programming during birdsong learning. Pathways afferent to HVc may participate more in sensory acquisition and sensorimotor learning during song development than is commonly assumed.
    Related
    articles:
  • Margoliash, D. (1997a) Distributed time-domain representations in the birdsong system. Neuron, 19(5): 963-966.
  • Margoliash, D. (1997b) Functional organization of forebrain pathways for song production and perception. J. Neurobiol., 33(5): 671-693.

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