Lesioning an attractor network: investigations of acquired dyslexia

A recurrent connectionist network was trained to output semantic feature vectors when presented with letter strings. When damaged, the network exhibited characteristics that resembled several of the phenomena found in deep dyslexia and semantic-access dyslexia. Damaged networks sometimes settled to the semantic vectors for semantically similar but visually dissimilar words. With severe damage, a forced-choice decision between categories was possible even when the choice of the particular semantic vector within the category was not possible. The damaged networks typically exhibited many mixed visual and semantic errors in which the output corresponded to a word that was both visually and semantically similar. Surprisingly, damage near the output sometimes caused pure visual errors. Indeed, the characteristic error pattern of deep dyslexia occurred with damage to virtually any part of the network.

[1]  O. L. Zangwill,et al.  Current problems in animal behaviour , 1962 .

[2]  J. Fodor,et al.  The structure of a semantic theory , 1963 .

[3]  J. Marshall,et al.  Syntactic and semantic errors in paralexia , 1966 .

[4]  H. C. LONGUET-HIGGINS,et al.  Non-Holographic Associative Memory , 1969, Nature.

[5]  J. Marshall,et al.  Patterns of paralexia: A psycholinguistic approach , 1973 .

[6]  Marvin Minsky,et al.  A framework for representing knowledge , 1974 .

[7]  T. Shallice,et al.  Word Recognition in a Phonemic Dyslexic Patient , 1975, The Quarterly journal of experimental psychology.

[8]  Allan Collins,et al.  A spreading-activation theory of semantic processing , 1975 .

[9]  Patrick Henry Winston,et al.  The psychology of computer vision , 1976, Pattern Recognit..

[10]  Stephen A. Ritz,et al.  Distinctive features, categorical perception, and probability learning: some applications of a neural model , 1977 .

[11]  A. J. Marcel,et al.  Aphasia, Dyslexia and the Phonological Coding of Written Words , 1977 .

[12]  Teuvo Kohonen,et al.  Associative memory. A system-theoretical approach , 1977 .

[13]  Phonemic Dyslexia: Errors of Meaning and the Meaning of Errors , 1978, The Quarterly journal of experimental psychology.

[14]  T Shallice,et al.  Semantic access dyslexia. , 1979, Brain : a journal of neurology.

[15]  K. Patterson.  What is right with “deep” dyslexic patients? , 1979, Brain and Language.

[16]  T Shallice,et al.  Modality specific word comprehension deficits in deep dyslexia. , 1980, Journal of neurology, neurosurgery, and psychiatry.

[17]  J. Requin.  Attention and Performance VII , 1980 .

[18]  Iconic reading in a case of alexia without agraphia caused by a brain tumor: A tachistoscopic study , 1980, Brain and Language.

[19]  James L. McClelland,et al.  Experimental tests of a hierarchical model of word identification , 1980 .

[20]  K E Patterson,et al.  Neuropsychological approaches to the study of reading. , 1981, British journal of psychology.

[21]  James L. McClelland,et al.  An interactive activation model of context effects in letter perception: I. An account of basic findings. , 1981 .

[22]  Edward E. Smith,et al.  Categories and concepts , 1984 .

[23]  James L. McClelland,et al.  An interactive activation model of context effects in letter perception: Part 2. The contextual enhancement effect and some tests and extensions of the model. , 1982, Psychological review.

[24]  Rhonda B. Friedman,et al.  On the underlying causes of semantic paralexias in a patient with deep dyslexia , 1982, Neuropsychologia.

[25]  R. Malatesha,et al.  Reading Disorders: Varieties and Treatments , 1982 .

[26]  Alfonso Caramazza,et al.  Modality-independent impairments in word processing in a deep dyslexic patient , 1982, Brain and Language.

[27]  Rosaleen A. McCarthy,et al.  Reading without Semantics , 1983 .

[28]  E. Warrington,et al.  CATEGORY SPECIFIC ACCESS DYSPHASIA , 1983 .

[29]  M. Mozer.  Letter migration in word perception. , 1983, Journal of experimental psychology. Human perception and performance.

[30]  H. Whitaker,et al.  Dyslexia: A Global Issue , 1983 .

[31]  C. Barry.  Consistency and Types of Semantic Errors in a Deep Dyslexic Patient , 1984 .

[32]  Deep dyslexia in a patient with crossed aphasia. , 1984, European neurology.

[33]  Alfonso Caramazza,et al.  The logic of neuropsychological research and the problem of patient classification in aphasia , 1984, Brain and Language.

[34]  Myrna F. Schwartz,et al.  What the classical aphasia categories can't do for us, and why , 1984, Brain and Language.

[35]  T. Shallice,et al.  Category specific semantic impairments , 1984 .

[36]  Gregory V. Jones.  Deep dyslexia, imageability, and ease of predication , 1985, Brain and Language.

[37]  Reading: Dissociation of the lexical and phonologic mechanisms , 1985, Brain and Language.

[38]  N. Geschwind,et al.  Mechanisms of Change after Brain Lesions a , 1985, Annals of the New York Academy of Sciences.

[39]  R. Berndt,et al.  Category-specific naming deficit following cerebral infarction , 1985, Nature.

[40]  Tim Shallice,et al.  Lexical processing in the absence of explicit word identification: Evidence from a letter-by-letter reader , 1986 .

[41]  Geoffrey E. Hinton,et al.  Learning representations by back-propagating errors , 1986, Nature.

[42]  A. Caramazza.  On drawing inferences about the structure of normal cognitive systems from the analysis of patterns of impaired performance: The case for single-patient studies , 1986, Brain and Cognition.

[43]  D. Rumelhart.  Learning internal representations by back-propagating errors , 1986 .

[44]  Geoffrey E. Hinton,et al.  Learning and relearning in Boltzmann machines , 1986 .

[45]  E. Warrington,et al.  Phonological Reading: Phenomena and Paradoxes , 1986, Cortex.

[46]  James L. McClelland,et al.  Parallel distributed processing: explorations in the microstructure of cognition, vol. 1: foundations , 1986 .

[47]  John C. Marshall,et al.  Deep dyslexia since 1980. , 1987 .

[48]  A. Young,et al.  “Neglect dyslexia” and the early visual processing of letters in words and nonwords , 1987 .

[49]  E K Warrington,et al.  The dissociation of visuospatial neglect and neglect dyslexia. , 1987, Journal of neurology, neurosurgery, and psychiatry.

[50]  E. Warrington,et al.  Categories of knowledge. Further fractionations and an attempted integration. , 1987, Brain : a journal of neurology.

[51]  G. C. Orden.  A ROWS is a ROSE: Spelling, sound, and reading , 1987 .

[52]  Mark Derthick.  Counterfactual Reasoning with Direct Models , 1987, AAAI.

[53]  T. Shallice.  From Neuropsychology to Mental Structure , 1988 .

[54]  Giuseppe Sartori,et al.  The oyster with four legs: A neuropsychological study on the interaction of visual and semantic information , 1998 .

[55]  M. Silveri,et al.  Interaction between vision and language in category-specific semantic impairment , 1988 .

[56]  Terrence J. Sejnowski,et al.  A Learning Algorithm for Boltzmann Machines , 1985, Cognitive Sciences.

[57]  Terrence J. Sejnowski,et al.  NETtalk: a parallel network that learns to read aloud , 1988 .

[58]  Glyn W. Humphreys,et al.  Cascade processes in picture identification , 1988 .

[59]  Christopher Barry,et al.  Accounts of oral reading in deep dyslexia , 1988 .

[60]  E. Warrington,et al.  Evidence for modality-specific meaning systems in the brain , 1988, Nature.

[61]  Geoffrey E. Hinton,et al.  Learning distributed representations of concepts. , 1989 .

[62]  H. Coslett,et al.  Evidence for preserved reading in 'pure alexia'. , 1989, Brain : a journal of neurology.

[63]  Sally Byng,et al.  A treatment for surface dyslexia , 1989 .

[64]  A. Caramazza,et al.  General to specific access to word meaning: A claim re-examined , 1989 .

[65]  James L. McClelland,et al.  A distributed, developmental model of word recognition and naming. , 1989, Psychological review.

[66]  James L. McClelland,et al.  Connections and disconnections: Acquired dyslexia in a computational model of reading processes. , 1989 .

[67]  Geoffrey E. Hinton,et al.  Parallel Models of Associative Memory , 1989 .

[68]  Geoffrey E. Hinton,et al.  Distributed Representations , 1986, The Philosophy of Artificial Intelligence.

[69]  A. Caramazza,et al.  Where Do Semantic Errors Come From? , 1990, Cortex.

[70]  Geoffrey E. Hinton.  20 – CONNECTIONIST LEARNING PROCEDURES1 , 1990 .

[71]  R. Morris.  Parallel Distributed Processing: Implications for Psychology and Neurobiology , 1990 .

[72]  Alfonso Caramazza,et al.  Selective impairment of semantics in lexical processing , 1990 .