Language Projects
The genetics of developmental dysgraphia
Advisor: Prof Anne Castles, Prof Max Coltheart, A/Prof Lyndsey Nickels
Co-advisor: Dr Ruth Brunsdon, Dr Saskia Kohnen
The goal of this study is to further our understanding of the genetic basis of spelling disorders by performing molecular DNA analyses on families where spelling disorders are highly prevalent. Developmental disorders of reading (dyslexia) and spelling (dysgraphia) affect 5-10% of the population. While remediation is often needed to improve reading and spelling performance, genetic studies may play a crucial role in understanding some of the causes of spelling disorders as well as the early identification of children at risk.
Skilled spelling is a complex process that relies on a number of different cognitive operations. This study will be based on a cognitive model that distinguishes between two major processing routes for generating spellings. Developmental disorders of spelling (and reading) reflect difficulties in learning these processing mechanisms.
Recent family and twin studies have shown that developmental reading and spelling disorders are substantially heritable. Reading and spelling are complex cognitive processes and multiple genes are thought to contribute to the pathogenesis of disorders in written language. However, the exact mode of inheritance remains unknown. Difficulties in replicating the results of these studies may have arisen from phenotype definitions that were not specific enough in defining the form of dyslexia or dysgraphia being studied. Very recent results from twin studies suggest that there may be a genetic basis to the two major processing routes mentioned above.
The study of specific phenotypes of a disorder, especially in a family group with a high number of affected members has previously proven to be a successful method in the study of cognitive genetics.
Further Readings:
Bates, T.C. (2006). Genes for reading and spelling. London Review of Education, 4(1), 31-47.
Bates, T.C., Castles, A., Coltheart, M., Gillespie, N., Wright, M. & Martin, N.G. (2004). Behaviour genetic analysis of reading and spelling: A component process approach. Australian Journal of Psychology, 56(2), 115-126.
de Kovel, C.G.F., Hol, F.A., Heister, J.G.A.M., Willemen, J., Sandkuijl, L., Franke, B. & Padberg, G.W. (2003). Genome wide scan identifies susceptibility locus for dyslexia on Xq27 in an extended Dutch family. Journal of Medical Genetics,
41(9), 625-657.
Romani, C., Olson, A. & Di Betta, A. M. (2005). Spelling disorders. In: Snowling, M. & Hulme, C. (Editors). The Science of reading: A handbook (pp. 431-447). Malden, MA: Blackwell Publishing.
Acquisition of semantics from a cross-linguistic perspective
Advisor: Professor Stephen Crain (MACCS)
Co-advisor: Dr. Rosalind Thornton (Linguistics/MACCS)
This project investigates how children acquiring different languages interpret natural language expressions that correspond to expressions in the vocabulary of classical logic. One series of studies investigates the interpretation of disjunction by children learning English, Chinese and Japanese. Disjunction (English 'or') can be used as a diagnostic test for several interesting semantic properties of natural languages. For example, many expressions in natural languages make disjunctive statements look like conjunctive statements. An English example is the preposition "before", but not "after." (Sue left before Tom or Bill entails that Sue left before Tom and before Bill; not so with "after.") In English, the interpretation of disjunction (as licensing such conjunctive entailments) is associated with other linguistic phenomena, such as the insertion of "anyone" (e.g., Sue left before anyone is fine, but Sue left after anyone is odd). This project investigates children's understanding of the semantics of such expressions across languages. A number of different expressions will be studied, including quantificational expressions (e.g., few, every, the), certain verbs (e.g., prevent), adverbs (never, all), conditionals (if c, then c), comparatives (stronger, taller), as well as the preposition before and after. Cross-linguistic research is critical to this project, to determine if there is a natural class of expressions that share semantic properties across languages, and to see which expressions are subject to cross-linguistic variation, and why.
Further Readings:
Crain, S., Goro, T. & Thornton, R. (2006). Language acquisition is language change. Journal of Psycholinguistic Research. (on-line first)
Crain, S. & Pietroski, P. (2002). Why language acquisition is a snap. The Linguistic Review, 19, 163-183.
Logic and language
Advisor: Professor Stephen Crain (MACCS)
Co-advisor: Professor Robert Dale (Computer Science)
This project investigates the overlap and areas of divergence between natural languages and the language of logic. Humans can reason, and humans can speak. But speaking a natural (human) language requires knowledge beyond that contributed by the language of logical reasoning. In some cases, language and logic overlap. For example, the meanings of natural language negation ("not") and disjunction ("or") are the same as the Boolean logical connectives of classical logic. Nevertheless, these connectives assume different semantic values in human languages, due to properties of natural languages that do not have counterparts in logical systems. For example, "focus" operators (only in English) license entailments that cannot be generated by the vocabulary of logic: Only John eats meat entails that everyone else does not eat meat). Other language-specific properties include conversational (pragmatic) principles, and the use of stress to resolve structural ambiguities. This project investigates the overlap of logic and language, and the residual contribution of language to the meanings of sentences, over and above that which can be reduced to logic. Whereas many researchers grant that that knowledge of logic is innate, and specific to humans, many of these same researchers would deny that knowledge of language is innate or specific to humans. Such claims can only be evaluated by disentangling the contributions of logic from language.
Further Readings:
Crain, S. & Pietroski, P. (2001). Nature, nurture and Universal Grammar. Linguistics and Philosophy, 24, 139-185.
Crain, S., Gualmini, A., & Meroni, L. (2000). The acquisition of logical words. LOGOS and Language, 1, 49-59.
Sentence processing from a cross-linguistic perspective.
Advisor: Professor Stephen Crain (MACCS)
Co-advisor: Associate Professor Veronika Coltheart (Psychology/MACCS)
This project evaluates a discourse-based model of sentence processing in real time, using a variety of research tools, and examining several languages. We will study how speakers of different languages process sentences with quantificational expressions such as "every" in English, "dou" in Chinese, and "dake" in Japanese. In Chinese, the same lexical item ("dou" or "dou-shi") is used to express the concepts that are expressed by different lexical items in English ("ever" and "only"). In English and Chinese the focus operator "only" is a free-standing word, whereas it is an affix in Japanese. This difference makes the acquisition of the concept of ONLY easier in Japanese than in English or Chinese. The experimental hypothesis is that Japanese sentences with "dake" and English sentences with "only" will be more difficult to process in real time, due to their greater ambiguity. This project examines the on-line sentence processing of such expressions in these three languages. In one set of experiments, an eye-movement recording system will be used to monitor fixation duration and eye movements by adult speakers of different languages to objects displayed on a computer screen, following auditory presentation of sentences in the target languages. Ideally, the same visual displays will be used for different sentences in a single language, to assess the different patterns of eye movements. In addition, sentences in different languages will be presented using the same visual scenes. The differences among these languages are the source of detailed predictions about difference in eye-movement patterns in response to the same visual scenes.
Further Readings:
Crain, S., Ni, W., & Conway, L. (1994). Learning, parsing, and modularity. In C. Clifton, L. Frazier and K. Rayner (eds.). Perspectives on Sentence Processing. Lawrence Erlbaum Associates, Hillsdale: NJ.
Crain, S. & Steedman, M. 1985. On not being led up the garden path; the use of context by the psychological parser. In Dowty, D.R. Karttunen, L. and Zwicky, A. (eds.). Natural Language Parsing: Psychological, Computational, and Theoretical Perspectives. Cambridge University Press. 320-358.
Masked priming effects in word recognition tasks
Advisor: Associate Professor Sachiko Kinoshita (Psychology/MACCS)
Co-Advisor: Dr. Matthew Finkbeiner (MACCS)
This project examines masked priming effects in reading. Masked priming is the facilitation in the time it takes a reader to respond to words that are preceded by primes, where the primes are presented so briefly that they are not consciously available to the reader. The project will test the hypothesis that readers are able to apply whatever processing operations are required in performing the task (e.g., lexical decision, semantic categorization) to the prime. This hypothesis leads to the prediction that masked priming effects will reflect the goal of the task, rather than some invariant aspect of word recognition.
Further Readings:
Kinoshita, S., & Lupker, S.J. (eds) (2003). Masked priming: The state of the Art. New York: Psychology Press.
Kunde, W., Kiesel, A., & Hoffmann, J. (2003). Conscious control over the content of unconscious cognition. Cognition, 88, 223-242.
Elliptical Structures in Child Language
Advisor: Dr. Rosalind Thornton (Linguistics/MACCS)
Co-advisors: Professor Stephen Crain (MACCS), Dr. Graciela Tesan (MACCS)
One way to assess children's emerging linguistic knowledge is by investigating their understanding of sentence structures that contain some kind of ellipsis (or 'missing' elements), such as verb phrase ellipsis, or gapping (where a verb is omitted from the second of two clauses). Some researchers claim that children (and adults) interpret elliptical structures using pragmatic inferences. This makes sense in some cases. For example, the following sentence is missing the verb 'likes' in the second clause: Mr. Smith likes Melbourne or Mrs. Smith _ Sydney. This sentence has the same interpretation as the corresponding sentence with the verb 'likes' repeated in the second clause. On the basis of examples like this, the child might formulate a pragmatic rule that relates verb-less sentences to their complete counterparts. However, there are limits to the utility of such an inference. For example, an elliptical version of a sentence with negation can differ in interpretation from its completed counterpart. So, the 'full' sentence Mr. Smith doesn't like Melbourne or Mrs. Smith doesn't like Sydney makes a disjunctive statement. It implies that either Mr. dislikes Melbourne OR Mrs. Smith dislikes Sydney. Compare this to the same sentence with the verb omitted: Mr. Smith doesn't like Melbourne or Mrs. Smith _ Sydney. This means that Mr. Smith dislikes Melbourne AND Mrs. Smith dislikes Sydney. This 'conjnutive' meaning indicates that the second disjunct (or Mrs. Smith Sydney) resides in the scope of negation in the underlying representation of the 'gapping' sentence, but not in the 'full' sentence. It turns out that this is a universal linguistic property. Demonstrating that children know these and other facts about ellipsis is a promising way to assess the source of children's linguistic knowledge - whether it is based on pragmatic inferences, or on innate knowledge of universal linguistic principles.
Further Readings:
Conroy, S., & Thornton, R. (2005). Children's knowledge of Principle C in discourse. In Y. Otsu (ed.). Proceedings of the Sixth Tokyo Conference on Psycholinguistics. (pp. 69-94) Tokyo: Hituzi Syobo Publishing Company.
Crain, S., & Pietroski, P. (2002). Why language acquisition is a snap. The Linguistic Review, 19, 163-183.
Language Control in Bilingual Speech Production
Advisor: Dr. Matthew Finkbeiner (MACCS)
Co-advisors: Dr. Sallyanne Palethorpe (MACCS)
The aim of this project is to investigate how bilinguals are able to keep their two (or more) languages separate when speaking. One particularly influential hypothesis is the language suppression hypothesis (Green, 1998). According to this hypothesis, bilinguals suppress Language A when speaking in Language B and vice versa. The majority of support for this hypothesis has come from studies of language switching, but the evidence from this paradigm has recently been called into question. As such, the language suppression hypothesis is presently lacking empirical support. As an alternative, the 'language activation hypothesis' has been proposed. This hypothesis is essentially the mirror opposite of the suppression hypothesis, but it too is lacking empirical support. The present project will seek to distinguish, empirically, between these two hypotheses. The project will include (initially) reaction time experiments and (later) MEG experiments with healthy individuals. Additionally, it is hoped that the project will include investigations of bilingual neuropsychological patients.
Further Readings:
Green, D.W. (1998). Mental control of the bilingual lexicosemantic system. Bilingualism: Language and Cognition, 1, 67-81.
Finkbeiner, M., Almeida, J., & Caramazza, A. (in press). Lexical selection in bilingual speech production does not involve language suppression. Journal of Experimental Psychology: Language, Memory and Cognition.
Children's Fragment Answers to Questions
Advisor: Dr. Rosalind Thornton (Linguistics/MACCS)
Co-Advisors: Dr. Stephen Crain (MACCS) and Dr. Graciela Tesan (MACCS)
One conversational norm is brevity. For example, the conversational maxim "Be Brief" guides our answers to questions. But there are also structural constraints on the forms that brief answers can take. Suppose someone asks Who is teaching child language at Macquarie? One can answer Susan, Susan is, her (pointing at Susan), or she is. But one cannot answer her is, or she. Another structural constraint is on the interpretation of answers. Consider the discourse between persons A and B, in (1).
(1)
A: Where was she sleeping?
B: In Susan's class.
Cf. She was sleeping in Susan's class.
Clearly, B does not think that A is using the pronoun she to refer to Susan - it must refer to some other salient female in the conversational context, just as in the full sentence She was sleeping in Susan's class. The goal of the present project is to investigate when and how these and other structural constraints on abbreviated answers to questions are mastered by two- and three-year-old children. The results of the proposed experimental studies with children will be pertinent in evaluating (a) theoretical accounts of ellipsis in natural language, and (b) the emergence of structure in language development.
Further Readings:
Crain, S. (1991) Language acquisition in the absence of experience. Behavioral and Brain Sciences, 14, 597-650.
Conroy, A. and Thornton, R. (2005) Children's knowledge of Principle C in discourse. In Y. Otsu (ed.) Proceedings of the Sixth Tokyo Conference on Psycholinguistics (pp. 69-94) Tokyo: Hituzi Syobo Publishing Company.
Advanced Reading:
Merchant, J. (2004) Fragments and ellipsis. Linguistics and Philosophy, 27, 661-738.
Number representation for count and mass nouns: evidence from brain-impaired and normal speakers
Advisor: Associate Professor Lyndsey Nickels (MACCS)
Co-Advisor: Dr. Britta Biedermann (MACCS)
The aim of this project is to identify how grammatical features are stored in our mental lexicon. In particular, we will explore the representation of number (singular vs plural) and countability (mass vs count), considering factors such as how frequently a word, i.e. a noun, occurs in spoken and written language, and whether its plural is regular or irregular. When we are presented with more than one object in our environment, how do we successfully generate the plural form of the appropriate noun? Many so called 'regular' and 'count' nouns, like cat, form plurals in the same (or similar) way by adding 's'. Yet other 'irregular' nouns, like child or mouse, have a radically different plural form. Other words either have no plural marker but are countable (e.g., sheep), others have no plural marking and are not not countable (e.g. sand - a 'mass' noun). Are all these words stored in the same way? The most influential theory of language production is that of Levelt, Roelofs and Meyer (1999; see Roelofs, 2000a; 2000b for a computational version). This incorporates three levels of processing when retrieving a word. First, the meaning, the lexical grammatical information, followed by the phonological word form. At each level of processing, how are words with different plural morphology represented? (e.g., countable words with no plural marking: sheep; or non-countable words with no plural marking: sand). In order to verify or falsify this theory we investigate speech errors from brain-impaired speakers (e.g., through stroke) and healthy speakers.
Further Readings:
Levelt, W. J. M., Roelofs, A., & Meyer, A. S. (1999). A theory of lexical access in speech production. Behavioral & Brain Sciences, 22, 1-75.
Luzatti, C., & DeBleser, R. (1996). Morphological processing in Italian agrammatic speakers. Brain & Language, 54, 26-74.
Pillon, A., de Partz, M.-P., Raison, A.-M., & Seron, X. (1991). L'orange, c'est le fruiter de l'orangine: A case of morphological impairment? Language and Cognitive Processes, 6, 137-167.
Taler, V., Jarema, G. (2007). Lexical access in younger and older adults: The case of the 'mass/count' distinction. Canadian Journal of Experimental Psychology, 61, 21-34.