 |
|||||||||||||||
 |
|
 |
|
Brain and Language Lab
| |
|
|||||||||
 |
|||||||||||||||
|
Research at the Brain and Language LabOur research examines the biocognitive - that is, the biological, psychological and computational - bases of language. Our broad goal is to elucidate multiple aspects of the biocognition of language, including its genetic, endocrine, cellular, physiological, anatomical, psychological and computational bases. Our approach is to propose and test hypotheses that integrate these apparently disparate bases. We investigate the neurocognition of both first (native) and second/subsequent (non-native) language. We are especially interested in individual and group differences in the biocognition of language, based on factors such as genetic variation, endocrine fluctuations, and sex and handedness differences. We examine normal acquisition and processing as well as language breakdown, recovery and rehabilitation in developmental and adult-onset disorders. Our research probes several language domains, including aspects of morphology, syntax and both conceptual and compositional semantics. Our studies examine these domains cross-linguistically, mostly in English, but also in Spanish, Italian, Japanese and Malayalam. We are particularly interested in understanding whether and how certain neurocognitive substrates subserve both language and non-language domains, such as memory, music and motor functions. Our research focuses on two basic language capacities: the "mental lexicon" (mental dictionary) of memorized words, and the "mental grammar," which underlies the rule-governed sequential and hierarchical combination of lexical forms into complex words (e.g., walk + -ed), phrases and sentences (e.g., Clementina excoriated the pachyderm). Previous neurocognitive models of lexicon and grammar have not emphasized the integration of knowledge across the relevant disciplines in biology, psychology, and linguistics (see Walenski and Ullman, 2005). Together with our colleagues, we have been testing a novel explanatory theory that brings together hypotheses and data from across these fields. According to this theory (referred to as the "declarative/procedural" theory or model), lexicon and grammar depend respectively upon two widely studied brain memory systems, whose genetic, endocrine, cellular, physiological, anatomical, psychological and computational bases are reasonably well-understood in both animals and humans. According to the declarative/procedural theory, lexical memory relies on declarative memory, a brain system which subserves the learning and use of fact and event knowledge, is rooted largely (but not only) in certain temporal lobe structures, and appears to be modulated by acetylcholine and estrogen. Aspects of grammar are instead posited to depend heavily on procedural memory, a brain system that subserves the acquisition and expression of motor and cognitive skills (e.g., riding a bicycle), may be specialized for sequences, is rooted largely (but not only) in specific frontal/basal-ganglia circuits, and appears to involve dopaminergic neurons. In the lab we test predictions of the declarative/procedural theory, and of competing explanatory theories, with a range of complementary methodological approaches, with the goal of revealing converging evidence: (1) psycholinguistic studies of cognitively unimpaired adults, using a variety of techniques, including eye-tracking; (2) developmental investigations of normal children and of children and adults with developmental disorders (Specific Language Impairment, Williams syndrome, ADHD, dyslexia, autism, and Tourette syndrome); (3) neurological studies of patients with adult-onset brain damage (Alzheimer's, Parkinson's, and Huntington's diseases, cerebellar damage, and aphasia); (4) electrophysiological and neuroimaging studies of normal and cognitively impaired subjects, using electroencephalography / Event-Related Potentials (EEG/ERPs) and functional Magnetic Resonance Imaging (fMRI); (5) genetic studies, both of twins and of the effects of genetic variation (in genes such as BDNF or COMT) on language and cognition, both in cognitively unimpaired individuals and in people with hereditary disorders; (6) endocrine studies of the effects of normal endocrine variation and of endocrine manipulations, within and between subjects, on language and cognition; (7) studies of the linguistic and cognitive effects of pharmacological manipulations (e.g., of acetylcholine) in normal and cognitively impaired subjects.
Representative publications on language and the declarative and procedural memory systems
Initial paper laying out theoretical perspective, with supporting empirical evidence: Theoretical and empirical overview papers: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198.
The biocognition of English inflectional and derivational morphology What are the biocognitive bases of the learning and use of various subtypes of English past-tense, plural and derivational forms in native speakers (e.g., regular, irregular, "inconsistent" regular, high and low frequency regular, affixed irregular)? How do the biocognitive correlates of morphology relate to those underlying syntax, conceptual semantics, compositional semantics, declarative memory, procedural memory, and various other functions and domains? Funders (Past and Present):Collaborators (Past and Present): Multiple, including most people listed under Collaborators. Lab Members: Multiple. Publications: Multiple; see Representative Publications. Cross-linguistic biocognitive studies of morphology Although most research on the biocognition of morphology has focused on English, investigations of morphology in other languages are also highly informative, particularly given the impoverished morphological complexity of English. We have examined or are currently examining the biocognitive correlates of morphology in Hungarian, Italian, Japanese, Malayalam and Spanish. Funders (Past and Present):Lab Members: Multiple. Publications: Biocognitive studies of syntax What are the biocognitive bases of various aspects of syntax, including agreement, tense, aspect, and the complement/adjunct distinction? How do the neurocognitive underpinnings of syntax relate to those of morphology, compositional semantics, and various non-linguistic domains, including declarative and procedural memory? We are examining these and related questions using a range of behavioral, neurological, neuroimaging and biological approaches. Funders (Past and Present):Collaborators (Past and Present): Multiple, including most people listed under Collaborators. Lab Members: Multiple, but currently primarily Harriet Bowden (lab almuna), John Drury (lab alumnus), Cristina Dye, Robbin Miranda (lab alumna), and Matthew Walenski (lab almunus). Publications: Multiple; see Representative Publications. Biocognitive studies of compositional semantics Linguists often distinguish two aspects of meaning. Conceptual meaning determines how individual words represent objects/events in the world, distinguishing dog and hammer. The conceptual meanings of non-compositional words are idiosyncratic and so must be stored in the mental lexicon. Compositional meaning is at least partially independent of the conceptual attributes of individual words, and may involve the mental grammar. We are investigating the biocognitive bases of compositional semantics, with a current focus on Negative Polarity Items and the Definiteness Effect, and how these relate to the biocognition of conceptual-semantics, morphology and syntax. Funders (Past and Present):Lab members: Multiple. Publications: Steinhauer, K., Drury, J.E., Portner, P., Walenski, M., Ullman, M.T. (In Press). Syntax, Concepts, and Logic in the Temporal Dynamics of Language Comprehension: Evidence from Event-Related Potentials. Neuropsychologia Genetics of language Interest in the genetics of language has increased dramatically in recent years. Different alleles (versions) of the same gene vary in their functionality, often resulting in subtle differences well within the normal range. One can take advantage of such variation to examine the genetic basis of differences in linguistic and other cognitive functions between individuals or groups. We are examining the genetic basis of aspects of language and other cognitive functions in three studies: one twin study, and two studies examining the linguistic and other cognitive effects of normal genetic variation in a set of genes that are known to play specific roles in the hippocampus, basal ganglia, and frontal cortex (BDNF, COMT, DAT, and other genes). Funders (Past and Present):Lab members: Matthew Gelfand, Kaitlyn Tagarelli, Matthew Walenski (lab almunus) Endocrinology of language How do hormones, and sex hormones in particular, affect language acquisition and processing? Do sex hormones underlie sex differences in language (see below)? How does the variation of sex hormones within and between subjects affect language? Do the natural fluctuations of estrogen, progesterone, and other hormones during the menstrual cycle affect language? Does Hormone Replacement Therapy (HRT) modulate language processing? We are currently attempting to answer these and related questions. Funders (Past and Present):Lab Members: Ivy Estabrooke (lab alumna) Publications: Pharmacology of language Do certain drugs (eg, cholinesterase inhibitors) modulate aspects of language acquisition and processing? We are currently investigating this question in patients with Alzheimer's disease, and in elderly healthy individuals. Funders (Past and Present):Lab Members: Ivy Estabrooke (lab alumna) Sex differences A well-established female advantage at remembering words is modulated by estrogen, and seems to depend on male/female differences in lexical and declarative memory. These data led us to the hypothesis that the two sexes may differ in their processing of complex linguistic forms. We predicted that males should generally compute complex forms by combining their parts (walk + -ed; the + cat), using the grammatical/procedural system. Because of their memory advantage, women may tend to store previously-encountered complex forms. Such sex differences are predicted only for complex structures that can be processed by either system - that is, previously encountered complex forms (walked), in particular those whose characteristics make them relatively easy to memorize, such as adjacent forms like walk and -ed, or the and cat, which can be memorized as something like a chunk. We are not suggesting that the sex difference is all-or-nothing. Rather, females are posited to have a significantly greater likelihood to remember complex forms than do males, who should thus rely more than females on composition. Importantly, the two sexes should not differ in all lexical and grammatical functions. Both sexes should store simple forms (cat), because these must depend on memory. And both sexes should compute, in the grammatical/procedural system, representations that are unlikely to have been memorized, such as novel regularized forms (proy + -ed) and certain types of complex syntactic relations (e.g., long distance dependencies). We are examining these issues using a range of biocognitive approaches. Funders (Past and Present):Lab members: Cristina Dye, Ivy Estabrooke (lab alumna), Matthew Gelfand, Joshua Hartshorne (lab alumnus), Robbin Miranda (lab alumna), Beth Prado (lab alumna), Karsten Steinhauer (lab alumnus), Matthew Walenski (lab almunus) Publications: The neurocognition of handedness and language Does the biocognition of language differ between left and right handers? If so, how? Do any such differences between left- and right-handers interact with other factors, such as differences in procedural memory function or between males and females? We are currently investigating these and related issues using psycholinguistic and ERP approaches. Lab members: Helen Carpenter, Matthew Gelfand, Sarah Lee (lab alumna), Matthew Moffa (lab alumnus), Matthew Walenski (lab almunus) Publications: Gelfand, M. P., Walenski, M., Moffa, M., Lee, S., & Ullman, M. T. (Under Review). The Influence of Handedness on Language: Storage versus Composition Differences in Left- and Right-Handers. The biocognition of language in Specific Language Impairment (SLI) How can we best characterize the biocognition of the learning and use of language by individuals with Specific Language Impairment (SLI)? What non-linguistic deficits do they have, and which linguistic deficits do these correlate with? How do children with SLI compensate for their linguistic and non-linguistic deficits, and which brain systems do they use for this compensation? We have been examining the novel hypothesis (the Procedural Deficit Hypothesis) that SLI can be largely explained by abnormalities of the brain structures underlying procedural memory, and that individuals with the disorder compensate, at least in part, with declarative memory. Collaborators (Past and Present):Lab Members: Laura Babcock, Cristina Dye, Matthew Gelfand, Martina Hedenius, Dominik Rus (lab alumnus) Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. The biocognition of language in autism How can the linguistic impairments in autism be characterized from a biocognitive perspective? What biocognitive systems are dysfunctional, and what systems might be involved in compensation? We have been examining the novel hypothesis (the Procedural Deficit Hypothesis of Autism) that the linguistic profile, and at least to some extent the profile of other cognitive abilities in autism, can be largely explained by abnormalities of the brain structures underlying procedural memory, while compensation relies, at least in part, on declarative memory. Funders (Past and Present):Lab Members: Cristina Dye, Matthew Walenski (lab almunus) Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. The biocognition of language in dyslexia What language functions are impaired in dyslexia? Do these impairments correlate with reading and other cognitive deficits, and with particular neural abnormalities? Which language functions are spared? Which brain systems do dyslexics use to compensate for their reading and linguistic deficits? We have been examining the novel hypothesis (the Procedural Deficit Hypothesis of Dyslexia) that the linguistic, reading, and at least certain other cognitive deficits in dyslexia can be largely explained by abnormalities of the brain structures underlying procedural memory, while compensation relies, at least in part, on declarative memory. Collaborators:Lab Members: Laura Babcock, Claudia Bonin (lab alumna), Cristina Dye, Matthew Gelfand, Joshua Hartshorne (lab alumnus), Martina Hedenius Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. The biocognition of language in ADHD What language functions are impaired in Attention Deficit Hyperactivity Disorder? Do these impairments correlate with other cognitive deficits, and with particular neural abnormalities? Which language functions are spared? Which brain systems do children with ADHD use to compensate for their linguistic deficits? We have been examining the novel hypothesis (the Procedural Deficit Hypothesis of ADHD) that language and certain other deficits in ADHD can be largely explained by abnormalities of the brain structures underlying procedural memory, while compensation relies, at least in part, on declarative memory. Collaborators:Lab Members: Jocelyn Curchack (lab alumna), Cristina Dye Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. The biocognition of lexicon and grammar in aphasia Are lexical and grammatical abilities, both in morphology and in other aspects of language, dissociable in aphasia, or in particular types of aphasia? Are lexical and grammatical impairments linked to lesions of particular brain structures? What is the relation between declarative and procedural memory and these impairments? What neurocognitive systems do aphasics use to compensate for their deficits? We are investigating these and related questions in aphasia. Funders (Past and Present):Lab Members: John Drury (lab alumnus), Roumyana Pancheva (lab alumna), Eiling Yee (lab alumna) Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. Ullman, M. T., Pancheva, R., Love, T., Yee, E., Swinney, D., Hickok, G. (2005). Neural correlates of lexicon and grammar: Evidence from the production, reading, and judgment of inflection in aphasia.
Brain and Language, 93(2), 185-238. A variety of neurodegenerative disorders lead to language deficits. Using behavioral, neuroimaging, and pharmacological approaches, we are examining the profile of language and non-language abilities in Alzheimer's, Parkinson's and Huntington's diseases, as well as in cerebellar degeneration. Funders (Past and Present):Lab Members: Roumyana Pancheva (lab alumna), Eiling Yee (lab alumna) Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. The biocognition of language in other disorders We have also examined or are currently examining language impairments in several other disorders, including in patients with amnesia (in the well-known patient H.M.); patients with cerebellar abnormalities or lesions; patients with schizophrenia; and individuals with the developmental disorders of Tourette syndrome, Developmental Coordination Disorder (DCD), phenylketonuria, or Williams syndrome. Collaborators (Past and Present):Lab Members: Roland Dimaya, Cristina Dye, Robbin Miranda (lab alumna), Matthew Walenski (lab almunus) Publications: Ullman, M. T. (2008). The role of memory systems in disorders of language. In B. Stemmer & H. A. Whitaker (Eds.), Handbook of the Neuroscience of Language. Oxford, UK: Elsevier Ltd. pp 189-198. Late-acquired second language Linguistic abilities, in both first and second language (L1 and L2), are sensitive to the age of initial language exposure. In both cases, late exposure may affect grammatical more than lexical functions. Consistent with the declarative/procedural theory, we have hypothesized that late L2 acquisition relies initially (i.e., in low-proficiency L2) largely on declarative memory (even for complex forms, which can be memorized as chunks), possibly due to an increase during childhood in the relative facility of learning in declarative as compared to procedural memory. However, with sufficient exposure to the L2, procedural memory should eventually acquire the grammar, leading to a high-proficiency L2 that resembles L1. We are examining this hypothesis in adult-acquired English and Spanish learned to different levels of proficiency, as well as in an artificial language (BROCANTO2) acquired to low and then high proficiency. In one project, we are investigating whether the neurocognitive correlates of the rules of this artificial language are similar to the neurocognitive correlates of a non-linguistic (Serial Reaction Time) procedural memory task in which subjects learn sequences that follow the same rules as those in the artificial language. In another project we are comparing the neurocognition of two groups of subjects: one which learns the artificial language in an explicit learning context, and the other which learns it in an implicit context. We are also investigating whether a range of linguistic and non-linguistic behavioral and brain measures, as well as other biological factors (e.g., genetic and endocrine variation), can predict the speed and ultimate attainment of L2 acquisition, and allow one to identify exceptional language learners as well as modulate L2 learning and use with pharmacological or other factors. Funders (Past and Present):Lab Members: Laura Babcock, Helen Carpenter, Sarah Grey, Stephanie Lukas, Kaitlyn Tagarelli Publications: Bowden, H.W., Gelfand, M.P., Sanz, C., Ullman, M.T. (In Press). Verbal Inflectional Morphology in L1 and L2 Spanish: A Frequency Effects Study Examining Storage versus Composition. Language Learning Morgan-Short, K., Sanz, C., Steinhauer, K., Ullman, M.T. (In Press). Second Language Acquisition of Gender Agreement in Explicit and Implicit Training Conditions: An Event-Related Potential Study. Language Learning Ullman, M. T. (2006). The Declarative/Procedural Model and the Shallow-Structure Hypothesis. Applied Psycholinguistics, 27(1), 97-105. Washington, DC: Georgetown University Press. (commentary on target article by H. Clahsen and C. Felser) Biocognitive studies of music How are the biocognitive bases of music similar to or different from those underlying language? In particular, is there a neurocognitive split in music that is analogous to the language distinction between lexicon and grammar? Using behavioral and ERP methods, we are investigating whether the memorization of known melodies depends largely on declarative memory, whereas the learning and processing of musical rules depends largely on procedural memory. We are also examining whether sex differences might be found within this distinction, and how the distinction might relate to the lexicon/grammar distinction in English morphological, syntactic, and lexical-conceptual processing. Funders (Past and Present):Lab Members: Robbin Miranda (lab alumna) Publications: Biocognitive epidemiology In very large samples of subjects, what associations are revealed between performance on linguistic and non-linguistic tasks, and with a wide range of biological markers, measured primarily in blood samples? We are examining these issues in a large sample of pregnant women, as well as in their children after birth, on the island of Lombok in Indonesia. Funders:Lab Members: Elizabeth Prado (lab alumna) Publications: |
|
|||||||||||||
|
|||||||||||||||
|
|
|
|
|
|
|
|||||||||