Position: Reader in Cognitive Neuropsychology Postgraduate Tutor Office: Rooms 510 & 512, School of Psychology, Birkbeck College, Malet Street, London, WC1E 7HX Phone: +44 20 7631 6386 Fax: +44 20 7631 6312 Email: m.thomas @bbk.ac.uk

Research

My primary interests are in cognitive and language development, both in terms of developmental processes in children and in the final cognitive structures they produce in the adult. Visit the homepage for the Developmental Neurocognition lab.

The Developmental Neurocognition lab is part of Birkbeck's Centre for Brain Function and Development, which was awarded one of the Queen's Anniversary Prizes for Higher and Further Education in February 2006. (Details).

My current research focuses on developmental disorders. I am interested in the window they offer on processes of typical development, as well as wider issues on the relation of genotype to phenotype (that is, the way in which genes relate to behaviour). A general introduction to the field of developmental disorders in the context of brain plasticity can be found here . As a specific case study, my recent work has investigated language development in individuals with Williams syndrome, a rare genetic disorder. Other research projects include visual processing and memory in Williams syndrome, autism, and Downs syndrome.

My research combines empirical methods and computational modelling, the latter currently focusing on connectionist models of development. Computational models allow greater precision in clarifying the mechanisms that may drive developmental change in cognitive systems (see below for review chapters on this work). Developmental computational models also provide a concrete framework within which to explore the neuroconstructivist position (e.g., Karmiloff-Smith, 1998; Elman et al., 1996). In relation to developmental disorders, this position proposes that behavioural deficits shown by individuals with developmental disorders should be viewed as the outcome of atypical developmental trajectories caused by initial differences in low-level neurocomputational constraints. Neuroconstructivism contrasts with an earlier approach of taking developmental deficits to be the direct analogue of brain damage in adults, where an impairment of a single ability is assumed to be explained by damage to an isolated component. I have pursued this line of argument both empirically (see below), and also in recent work on the computational modelling of developmental disorders, in the specific case of past tense formation in Williams syndrome, in the general case of the relation of developmental and acquired disorders, and in exploring the problem of developmental deficits that may have multiple underlying causes (see below).

I am also interested in the ways in which fully developed systems break down and recover from damage, including the status of double dissociations in deficits. See here for modelling work exploring stochastic double dissociations in a connectionist model of semantic memory under varying assumptions of modular structure. Other theoretical work includes includes the computational factors that drive typical and atypical emergent of modularity across development, current computational approaches to individual differences and intelligence (see below), and computational approaches to explaining deficits in autism (see below).

As well as work in developmental and acquired disorders, I have other interests in the psychology of language, including bilingual language processing (see below) and metaphor processing (see below). Lastly, I have carried out theoretical work evaluating the philosophical status of connectionist models (see below) and computational models of consciousness (see below).

Grant support

My research is currently supported by grants from the Medical Research Council, the British Academy, and the European Commission.

Post-docs

Dr. Fiona Richardson. Cognitive variability.

Dr. Martin Redington. Computational models of typical and atypical syntax acquisition.

Neil Forrester. Cognitive variability.

Students

Sarah Snoxall. Animacy in categorisation.

Georgina Portelli. Grammatical and conceptual categories of gender in Maltese and English.

Frank Baughman. The neurocomputational basis of individual variation.

Caspar Addyman. The development of categories in infancy.

Joe Wiltshire. The development of relational structure.

Teaching

Lecture notes for MSc Cognitive Neuropsychology course "Disorders of language" can be found here.

Lecture notes for developmental disorders lecture on BSc Brain and Cognitive Development Option can be found here.

Lecture notes for language acquisition lectures on BSc "Language: A Psychological Perspective" course (P3.7) can be found here.

Overheads for UCL MRCPsych lecture on "Cognitive and Language Development" can be found here. Handouts are here.

PhD opportunities

I am currently interested in taking on postgraduate students for empirical or computational projects in the area of language development and developmental disorders. Possible specific projects include the following topics: (1) the development of semantics in language disorders (2) bilingual language development and breakdown (3) atypical syntax acquisition (4) inflectional morphology (5) the emergence of modularity (6) modelling Karmiloff-Smith's theory of representational redescription (7) metaphor development (8) computational modelling of intelligence (9) face recognition (10) abductive inference. Please contact me directly for further information and to discuss possible projects.

Publications

New:

Westermann, G., Mareschal, D., Johnson, M. H., Sirois, S., Spratling, M. W., & Thomas, M. S. C. (2007). Neuroconstructivism. Developmental Science, 10:1, 75-83. Click here for PDF version (189K)

Mareschal, D., Johnson, M., Sirios, S., Spratling, M., Thomas, M. S. C., & Westermann, G. (2007). Neuroconstructivism: How the brain constructs cognition. Oxford: Oxford University Press. Amazon.

Mareschal, D. & Thomas M. S. C. (in press) Computational modeling in developmental psychology. IEEE Transactions on Evolutionary Computation (Special Issue on Autonomous Mental Development). Click here for PDF version (622K)

Mareschal, D & Thomas, MSC (2006). How computational models help explain the origins of reasoning. IEEE Computational Intelligence Magazine. IEEE. Click here for PDF version (404K)

Thomas, M. S. C. (2006). Williams syndrome: Fractionations all the way down? Cortex, 42, 1053-1057. Click here for PDF version (69K)

Submitted publications (please do not cite without permission):

Thomas, M. S. C. et al. (submitted). The use of developmental trajectories in studying genetic developmental disorders. Manuscript submitted for publication. Click here for PDF version (277K)

Richardson, F. & Thomas, M. S. C. (submitted). Critical periods and catastrophic interference in self-organising feature maps. Manuscript submitted for publication. Click here for PDF version (297K)

Thomas, M. S. C. & Johnson, M. H. (submitted). New advances in understanding sensitive periods in development. Manuscript submitted for publication. Click here for PDF version (46K)

Thomas, M. S. C., & McClelland, J. L. (submitted). Connectionist models of cognition. To appear in: R. Sun (Ed.), Cambridge handbook of computational cognitive modelling. Cambridge: Cambridge University Press. Click here for PDF version (264K)

Thomas, M. S. C. (submitted). Language acquisition in developmental disorders. To appear in: M. Kail, M. Hickmann & M. Fayol (Eds.), Proceedings of the International Conference on First and Second Language Acquisition, Paris 2006. Click here for PDF version (107K)

Empirical and theoretical work on developmental disorders:

Thomas, M. S. C., Dockrell, J. E., Messer, D., Parmigiani, C., Ansari, D., & Karmiloff-Smith, A. (2006). Speeded naming, frequency and the development of the lexicon in Williams syndrome. Language and Cognitive Processes, 21(6), 721-759. Click here for PDF version of uncorrected proofs (477K)

Thomas, M. S. C. (2005). Plotting the causes of developmental disorders. Trends in Cognitive Sciences, Vol. 9, Issue 10, 465-466. Click here for PDF version (17K)

Thomas, M. S. C., & Karmiloff-Smith, A. (2005). Can developmental disorders reveal the component parts of the human language faculty? Language Learning and Development, 1(1), 65-92. Click here for PDF version (111k)

Thomas, M. S. C. (2005). Constraints on language development: Insights from developmental disorders. In: P. Fletcher & J. Miller (Eds.) Language Disorders and Developmental Theory. John Benjamins. Click here for PDF version of uncorrected proofs (no references) (166k), Click here for version with full book references (444k)

Karmiloff-Smith, A. & Thomas, M. S. C. (2005). Les troubles du developpement viennent-ils confirmer les arguments de la psychologie evolutionniste? Une approche neuro-constructiviste. Revue Francaise de Pedagogie, 152, 11-19. Click here for (fuzzy) PDF version (4700k).

Two book reviews of "Understanding Williams syndrome: Behavioural Patterns and Interventions", by Eleanor Semel and Sue Rosner. ISBN0-8058-2618-1, Lawrence Erlbaum Associates, 2003. 456 pages. For Cortex journal: Thomas, M. S. C. (2006). Williams syndrome: Fractionations all the way down? Cortex, 42, 1053-1057. Click here for PDF version (69K). For The Williams Syndrome Foundation UK magazine (Issue No. 51, Summer 2004): "From scientific research to intervention in Williams syndrome." Published article (4.5mb), Final draft (108k).

Laing, E., Grant, J., Thomas, M. S .C. & Karmiloff-Smith, A. (2005). Love is . . . an abstract word: The influence of phonological and semantic factors on verbal short-term memory in Williams syndrome. Cortex, 41 (2), 169-179. Click here for PDF version (117k)

Karmiloff-Smith, A., Thomas, M. S. C., Annaz, D., Humphreys, K., Ewing, S., Grice, S., Brace, N., Van Duuren, M., Pike, G., & Campbell, R. (2004). Exploring the Williams syndrome face processing debate: The importance of building developmental trajectories. Journal of Child Psychology and Psychiatry and Allied Disciplines. 45:7, 1258-1274. Click here for PDF version (187k)

Karmiloff-Smith, A., & Thomas, M. S. C. (2004). Can developmental disorders be used to bolster claims from Evolutionary Psychology?: A neuroconstructivist approach. In J. Langer, S. Taylor Parker & C. Milbrath (Eds.), Biology and Knowledge Revisited: From Neurogenesis to Psychogenesis (pp. 307-321). Click here for PDF (154k)

Karmiloff-Smith, A., Ansari, D., Campbell, L., Scerif, G., & Thomas, M. S. C. (2006). Theoretical implications of studying genetic disorders: The case of Williams syndrome. To appear in C. Morris, H. Lenhoff & P. Wang (Eds.), Williams-Beuren Syndrome: Research and Clinical Perspectives (pp. 254-273). Baltimore: The Johns Hopkins University Press. Click here for Word97 version (102k)

Karmiloff-Smith, A. & Thomas, M. S. C. (2003). What can developmental disorders tell us about the neurocomputational constraints that shape development? The case of Williams syndrome. Development and Psychopathology. 15, 969-990. Click here for Word97 version (292k)

Thomas, M. S. C. (2003). Limits on plasticity. Journal of Cognition and Development, 4(1), 95-121. Click here for PDF of uncorrected proof (111k)

Ansari, D., Donlan, C., Thomas, M. S. C., Ewing, S., Peen, T., & Karmiloff-Smith, A. (2003). How children with Williams syndrome understand why counting counts. Journal of Experimental Child Psychology, 85, 50-62. Abstract

Thomas, M. S. C. (2002). Development as a cause in developmental disorders. Computational Intelligence, 18(1), 50-54.

Karmiloff-Smith, A., Scerif, G., & Thomas, M. S. C. (2002). Different approaches to relating genotype to phenotype in developmental disorders. Developmental Psychobiology, 40, 311-322. Click here for Word97 version (221k)

Thomas, M. S. C., Grant, J., Barham, Z., Gsödl, M., Laing, E., Lakusta, L., Tyler, L. K., Grice, S., Paterson, S. & Karmiloff-Smith, A. (2001). Past tense formation in Williams syndrome. Language and Cognitive Processes, 16 (2/3), 143-176. Abstract [Reprinted in: D. Bishop (2001) Language and cognitive processes in developmental disorders. Sussex, UK: Psychology Press.]

Thomas, M. S. C. (2000). Neuroconstructivism's promise. Developmental Science, 3(1), 35-37. Click here for Word97 document (final draft) (35 k)

Thomas, M. S. C. & Karmiloff-Smith, A. (1999). Quo vadis modularity in the 1990s? Learning and Individual Differences, 10(3), 245-250. Abstract

Computational modelling and development:

Thomas, M. S. C., Forrester, N. A., & Richardson, F. M. (2006). What is modularity good for? In Proceedings of the 28^th Annual Conference of the Cognitive Science Society, July 26-29, Vancouver, BC, Canada. Click here for PDF version (123K)

Richardson, F., & Thomas, M. S. C. (2006). The benefits of computational modelling for the study of developmental disorders: Extending the Triesch et al. model to ADHD. Developmental Science, 9(2), 151-155. Click here for PDF version (132K)

Richardson, F. M., Baughman, F. D., Forrester, N. A., & Thomas, M.S.C. (2006). Computational modeling of variability in the Balance Scale Task. In Proceedings of the 7^th International Conference of Cognitive Modeling. Click here for PDF version (220K)

Richardson, F. M., Forrester, N. A., Baughman, F. D., & Thomas, M. S. C. (2006). Computational modeling of variability in the Conservation Task. In Proceedings of the 28^th Annual Conference of the Cognitive Science Society, July 26-29, Vancouver, BC, Canada. Click here for PDF version (185K)

Thomas, M. S. C., & Richardson, F. (2006). Atypical representational change: Conditions for the emergence of atypical modularity. In Y. Munakata & M. H. Johnson (Eds.), Processes of change in brain and cognitive development: Attention and Performance XXI (pp. 315-347). Oxford: Oxford University Press. Click here for B&W PDF version (270k) and here for colour PDF version (260k)

Thomas, M. S. C. (2005). Characterising compensation. Cortex, 41(3), 434-442. Click here for PDF version (193K) [Reprinted in: D. V. M. Bishop, M. A. Eckert & C. M. Leonard (2005) The Neurobiology of Developmental disorders. Milan, Italy: Masson.]

Abreu, A. M., French, R. M., Annaz, D., Thomas, M. S. C., & de Schonen, S. (2005). A visual conflict hypothesis for global-local visual deficits in Williams syndrome: Simulations and data. Proceedings of the 27th Annual Meeting of the Cognitive Science Society, Stresa, Italy, 21 July 2005. Click here for PDF version (265k)

Thomas, M. S. C. (2004). How do simple connectionist networks achieve a shift from "featural" to "correlational" processing in categorisation? Infancy, 5(2), 199-207. This article is accepted for publication in Infancy Journal and is copyrighted by Lawrence Erlbaum Associates. The following PDF is for personal use and readers must contact LEA for permission to reprint or use the material in any form. Click here for PDF version (89k) - Supporting material for the Infancy article (simple models and analysis)

Thomas, M. S. C. & Redington, M. (2004). Modelling atypical syntax processing. In W. Sakas (Ed.), Proceedings of the First Workshop on Psycho-computational models of human language acquisition at the 20th International Conference on Computational Linguistics. Pp. 85-92. Click here for PDF version (90k)

Thomas, M. S. C. & Karmiloff-Smith, A. (2003). Modelling language acquisition in atypical phenotypes. Psychological Review, 110(4), 647-682. Click here for Word97 version of the final draft (909k) Click here for PDF of uncorrected proofs (3040k) Here for final pdf (11mb)

Thomas, M. S. C. (2003). Multiple causality in developmental disorders: Methodological implications from computational modelling. Developmental Science, 6 (5), 537-556. Click here for PDF of uncorrected proofs (648k)

Karmiloff-Smith, A. & Thomas, M. S. C. (2003). Developmental disorders. In M. A. Arbib (Ed.) The Handbook of brain theory and neural networks, 2^nd Edition. Cambridge, MA: MIT Press. Click here PDF of current draft (70 k)

Thomas, M. S. C. & Karmiloff-Smith, A. (2003). Connectionist models of development, developmental disorders and individual differences. In R. J. Sternberg, J. Lautrey, & T. Lubart (Eds.), Models of Intelligence: International Perspectives, (p. 133-150). American Psychological Association.Click here for Word 97document (final draft) (114k)

Thomas, M. S. C. & Karmiloff-Smith, A. (2002). Are developmental disorders like cases of adult brain damage? Implications from connectionist modelling. Behavioral and Brain Sciences, Vol. 25, No. 6, 727-788. Click here for PDF of uncorrected proofs (285k)

Thomas, M. S. C. & Karmiloff-Smith, A. (2002). Residual Normality: Friend or Foe? Behavioural and Brain Sciences. See above for download

Thomas, M. S. C. & Karmiloff-Smith, A. (2002). Modelling typical and atypical cognitive development. In U. Goswami (Ed.), Handbook of Childhood Development (pp. 575-599). Blackwells Publishers. Click here for Word97 document (final draft) (184 k)

Mareschal, D. & Thomas, M. S. C. (2001). Self-organisation in normal and abnormal cognitive development. In A. F. Kalverboer, & A. Gramsbergen (Eds.). Handbook of Brain and Behaviour in Human Development (pp.743-766). Kluwer Academic Press.Click here for Word97 document (final draft) (293k)

Computational modelling and acquired deficits:

Thomas, M.S.C. and N. M. de Wet (1998). Stochastic double dissociations in distributed models of semantic memory. In D. Heinke and G. Humphreys (Eds.). Proceedings of the 5th Neural Computation and Psychology Workshop. Springer. Click here for Word97 version (1,425 k)

Connectionist Modelling:

Thomas, M. S. C. (2004). The state of connectionism in 2004. Parallaxis, 8, 43-61. Click here for html version

Thomas, M.S.C. and Stone, A. (1998). Cognitive connectionist models are just models, and connectionism is a progressive research programme. Commentary on Green on Connectionist Explanation. Psycoloquy, 36. HTML

Bilingual language processing:

Thomas, M. S. C. & Van Heuven, W. (2005). Computational models of bilingual comprehension. To appear in J. F. Kroll & A. M. B. De Groot (Eds.) Handbook of Bilingualism: Psycholinguistic Approaches. Oxford University Press. Click here for Word97 document of final draft

Thomas, M. S. C. (2002). Theories that develop. Bilingualism: Language & Cognition, 5(3), 216-217. Click here for pdf (174k)

Thomas, M. S. C. & A. Allport (2000). Language switching costs in bilingual visual word recognition. Journal of Memory and Language, 43, 44-66. Abstract

Thomas, M.S.C. (1998). Bilingualism and the Single route / Dual Route debate. Proceedings of the 20th Annual Conference of the Cognitive Science Society. Erlbaum. Pp. 1061-1066. Word 97 document (98 k)

Thomas, M. S. C. (1997). Connectionist networks and knowledge representation: The case of bilingual lexical processing. Unpublished D.Phil. thesis, Oxford University. Click here for Word97 version (1742 k), Click here for PDF file of Contents pages and Abstract (74 k), Click here for PDF file of Appendices (30.2mb).

Thomas, M.S.C. (1997). Distributed representations and the bilingual lexicon: One store or two? In J. Bullinaria, D. Glasspool, and G. Houghton (Eds.), Proceedings of the 4th Annual Neural Computation and Psychology Workshop. Springer. Click here for Word97 version (454 k)

Thomas, M.S.C., and Plunkett, K. (1995). Representing the bilingualĖs two lexicons. In Proceedings of the 17th Annual Conference of the Cognitive Science Society. Erlbaum. Pp. 760-765. Click here for PDF (35 k)

Metaphor:

Thomas, M. S. C. & Mareschal, D. (2001). Metaphor as categorisation: A connectionist implementation. Metaphor and Symbol, 16 (1/2), 5-27. Click here for Word97 version (final draft) (325 k)

Thomas, M. S. C., Mareschal, D., & Hinds, A. (2001). A connectionist account of the emergence of the literal-metaphorical-anomalous distinction in young children. Proceedings of the 23rd Annual Meeting of the Cognitive Science Society. Erlbaum. PDF (90 k)

Thomas, M. S. C. & Mareschal, D. (1999). Metaphor as categorisation: A connectionist implementation. Proceedings of the AISBĖ99 Symposium on Metaphor, Artificial Intelligence, and Cognition. The Society for the Study of Artificial Intelligence and the Simulation of Behaviour. Pp. 1-10.

Thomas, M.S.C. and Mareschal, D. (1997). Connectionism and psychological notions of similarity. Proceedings of the 19th Annual Conference of the Cognitive Science Society. Erlbaum. PDF (76 k)

Thomas, M.S.C. and Mareschal, D. (1996). A connectionist model of Metaphor by Pattern Completion. In Proceedings of the 18th Annual Conference of the Cognitive Science Society. Erlbaum. Pp. 696-701.

Computational models of consciousness:

Atkinson, A.P., Thomas, M.S.C., & Cleeremans, A. (2000). Consciousness: Mapping the theoretical landscape. Trends in Cognitive Sciences, 4 (10), 372-382. PDF (308 k)

Atkinson, A.P. and Thomas, M.S.C. (1999). What makes us conscious? Journal of Intelligent Systems, 9, 307-354. Abstract

Thomas, M.S.C. and Atkinson, A.P. (1999). Quantities of qualia. Behavioural and Brain Sciences, 22, 169-170

(Page last modified 12 March 2007)