Simon Fischer-Baum

3rd Year Graduate student

fischerbaum@cogsci.jhu.edu

Department of Cognitive Science 

Johns Hopkins University
CV

office - Krieger 239      office hours – tba                   office telephone - (410) 516-7625

Research Interests

I am interested in studying the representations and processes the human mind/brain uses to produce and comprehend language. Individuals whose cognitive system have been damaged after brain-damage provide a unique opportunity to answer some of these questions as (1) specific cognitive processes might be damaged, while others remain intact or (2) errors made by these subjects might reveal underlying structure. I am also interested in understanding the causes of the cognitive deficits observed in these brain-damaged individuals and computational modeling of the intact and damaged system.

 

Representations of Letter order in Orthographic Representations:

Our knowledge of the spelling of a word contains information about both letter identities and letter order. How is order information encoded? Brenda Rapp, Michael McCloskey and I have been studying several brain-damaged individuals who perseverate – incorrectly insert previously produced responses – in spelling tasks. For example, after correctly spelling ROUGH, one individual intruded a G into his spelling of CHANCE, instead producing CHANGE. These intruded letters appear in the same position in the error as they appeared in the previous response more often than would be expected by chance. Careful analysis allows us to determine the type of position represented in the orthographic representations required for spelling. Michael McCloskey and I have been studying similar errors made by neurologically-intact subjects in an ordered list-recall to determine whether representation of order information is shared between short-term memory tasks and spelling. Paul Smolensky and I have been investigating how priming data in the reading literature bears on theories of how orthographic position is encoded in our orthographic input representations. For example, do relative and transposition priming effects provide evidence for context-dependent rather than context-independent representations or do they constitute evidence for coarse-coded rather than fine-tuned position representations?

 

Orthographic Morphology:

Recent work has demonstrated that certain patients perform worse in tasks that require morphological production when they are asked to produce the written form than the spoken form, including some patients who perform at normal levels in spoken production but catastrophically with written production. We are studying one of these individuals to determine the types of morphological forms – regular vs. irregular, inflectional vs. derivational – that she is impaired on as well as the types of errors she is making on these forms to understand morpheme representation and the morphological processes that occur in the orthographic system.

 

The Underlying Causes of Perseverations:

Many individuals perseverate after brain-damage. Several proposals have been put forth for the underlying causes of these perseverations, which have consequences for our understanding of the temporal dynamics of cognitive processing. The perseveration deficit argues that representational units fail to be normally suppressed after they have been produce, preventing the current target units from being selected. The deafferentation hypothesis states that perseverations occur when there is less information flowing from the previous processing level to the production level, leaving the normally activated previously produced item the most active of the set of units. We are studying the perseveration errors made by a number of brain-damaged individuals to understand what type(s) of deficit(s) leads to perseverations.

Education
2005-present, Cognitive Science, Johns Hopkins University

  • 1st Qualifying Paper (11/06): The Representation of Orthographic Letter Position: Evidence from Position Preserving Perseverations

Advisor: Brenda Rapp

B.A. 2003, Neuroscience and Behavior (with Honors), Columbia University

  • Honors Thesis: Stress and Syllables: Evidence from a Word-Word Interference Paradigm

Advisor: Michele Miozzo

Teaching

  • 050.626 Foundations of Cognitive Science A (Spring 2008)
  • 050.672 Formal Methods in Cognitive Science: Neural Networks (Fall 2007)
  • 050.311 Written Language: Normal Processing and Disorders (Spring 2007)
  • 050.105 Introduction to Cognitive Neuropyschology (Fall 2006)
  • 050.203 Cognitive Neuroscience: Exploring the Living Brain (Spring 2006)

Coursework

  • 050.672 Formal Methods in Cognitive Science: Neural Networks Smolensky
  • 050.670 Formal Methods in Cognitive Science: Language Frank
  • 050.626 Foundations of Cognitive Science A Smolensky
  • 050.625 Phonology I Burzio
  • 050.802 Research Seminar: Cognitive Processes Rapp
  • 050.602 Topics in Cognitive Neuropsychology Rapp
  • 200.314 Advanced Statistical Methods Yantis
  • 200.357 Cognitive Neuroscience of Memory Stark
  • 050.311 Written Language: Normal Processing and Disorders Rapp
  • 050.824 Seminar on Lexical Representation Burzio and Badecker
  • 050.680 Learning Theory Frank and Smolensky
  • 150.658 Topics in the Philosophy of Language Gross
  • 050.826 Research Seminar in Formal Approaches to Cognitive Science Frank and Smolensky

 

Conferences Attended

  • 14th Annual Meeting of the Cognitive Neuroscience Society – (San Francisco 2008)
  • 48th Annual Meeting of the Psychonomics Society – (Long Beach 2007)
  • 45th Annual Meeting of the Academy of Aphasia – (Washington DC 2007)
  • 29th Annual Meeting of the Cognitive Science Society – (Nashville 2007)
  • 44th Annual Meeting of the Academy of Aphasia – (Victoria 2006)
  • 5th International Conference on the Mental Lexicon – (Montreal 2006)
  • 3rd International Workshop on Language Production – (Chicago 2006)
  • 12th Annual Meeting of the Cognitive Neuroscience Society – (New York 2005)

Posters and Presentations

  • Fischer-Baum, S. and Rapp, B. (2008). Perseveration Errors and the Temporal Dynamics of Cognitive Processes. Poster presented at the 14th Annual Meeting of the Cognitive Neuroscience Society, San Francisco
  • Rapp, B. and Fischer-Baum, S. (2007). Orthographic Morphology: Evidence from Acquired Dysgraphia. Poster presented at the 48th Annual Meeting of the Psychonomics Society, Long Beach
  • Fischer-Baum, S., Rapp, B. and McCloskey, M. (2007). Encoding of Letter Position in Orthographic Representation: Evidence from Dysgraphia. Poster presented at the 48th Annual Meeting of the Psychonomics Society, Long Beach
  • Fischer-Baum, S., Rapp, B. and McCloskey, M. (2007). The Representation of Letter Position: Evidence from Dysgraphia. Talk given at 45th Annual Meeting of the Academy of Aphasia, Washington DC.
  • Rapp, B., Fischer-Baum, S., and Pastor, T. (2007). Perseveration and Graphemic Representations: Double Letters and Digraphs. Poster given at 45th Annual Meeting of the Academy of Aphasia, Washington DC.
  • Fischer-Baum, S., Rapp, B. and McCloskey, M. (2007). The Representation of Letter Position in Spelling: Evidence from Acquired Dysgraphia. Poster presented at the 29th Annual Meeting of the Cognitive Science Society, Nashville. [pdf]
  • Rapp, B., Barriere, I. and Fischer-Baum, S. (2006). Morpho-orthography: Evidence of modality specific morphological processes. Talk given at the Fifth International Conference on the Mental Lexicon, Montreal.
  • Fischer-Baum, S., Postman, J. and Miozzo, M. (2006). The dissociability of morphological processing and lexical access. Poster presented at the 44th Annual Meeting of the Academy of Aphasia, Victoria.