Structure and deterioration of semantic memory: a neuropsychological and computational investigation.

  title={Structure and deterioration of semantic memory: a neuropsychological and computational investigation.},
  author={Timothy T. Rogers and Matthew. A. Lambon Ralph and Peter Garrard and Sasha Bozeat and James L. McClelland and John R. Hodges and Karalyn E Patterson},
  journal={Psychological review},
  volume={111 1},
Wernicke (1900, as cited in G. H. Eggert, 1977) suggested that semantic knowledge arises from the interaction of perceptual representations of objects and words. The authors present a parallel distributed processing implementation of this theory, in which semantic representations emerge from mechanisms that acquire the mappings between visual representations of objects and their verbal descriptions. To test the theory, they trained the model to associate names, verbal descriptions, and visual… 

Semantic memory is an amodal, dynamic system: Evidence from the interaction of naming and object use in semantic dementia

Semantic assessment revealed a parallel decline in verbal and nonverbal aspects of conceptual knowledge, reflecting a gradual degradation of a single amodal semantic system.

The reign of typicality in semantic memory

  • K. Patterson
  • Psychology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2007
The results suggest that perceptual and conceptual processing form an interactive continuum rather than distinct stages, and that typicality effects reign throughout this continuum.

Concepts, Control, and Context: A Connectionist Account of Normal and Disordered Semantic Cognition

The model accounts for executive influences on semantics by including a controlled retrieval mechanism that provides top-down input to amplify weak semantic relationships and successfully codes knowledge for abstract and concrete words, associative and taxonomic relationships, and the multiple meanings of homonyms, within a single representational space.

The Representation of Objects in the Brain, and Its Link with Semantic Memory and Language: a Conceptual Theory with the Support of a Neurocomputational Model

Many conceptual theories of semantic memory have been proposed in past decades, based on two fundamental pieces of information: the behavior of patients with neurological lesions in specific brain areas, who exhibit deficits in word recognition, and results of more recent neuroimaging studies, putting in evidence which different brain areas participate to semantic tasks.


Semantic Representations Thus far, our discussion of the representation of semantic memory has been confined to physical properties of concrete objects. When Allport articulated his theory of the

Conceptual structure: Towards an integrated neurocognitive account

It is argued that distributed accounts of feature-based representations have considerable explanatory power, and that a cognitive model of conceptual representations is needed to understand their neural bases.

Conceptual flexibility: Behavioral and neural variations in semantic memory retrieval

In three studies, evidence is found that while conceptual knowledge is grounded in neural substrates, several factors contribute to variations in semantic memory retrieval and suggests that semantic representations, integral to a memory system often thought of as free of contextual constraints, contain meaningful variations across contexts, people, and use.

Concepts and categories: a cognitive neuropsychological perspective.

Developments within the embodied cognition framework point toward a new approach for understanding category specificity in terms of the coordinated influences of diverse regions and cognitive systems.

Presemantic Cognition in Semantic Dementia: Six Deficits in Search of an Explanation

It is argued that patients with semantic dementia would reveal a specific pattern of impairment on six different tasks typically considered pre- or non- semantic: reading aloud, writing to dictation, inflecting verbs, lexical decision, object decision, and delayed copy drawing are a principled consequence of a primary semantic impairment.



Conceptual Structure and the Structure of Concepts: A Distributed Account of Category-Specific Deficits

A new account of the fine-grained structure of semantic categories derived from neuropsychological, behavioral, and developmental data is presented, claiming that the distinctiveness of functional features correlated with perceptual features varies across semantic domains and that category structure emerges from the complex interaction of these variables.

Loss of semantic memory: implications for the modularity of mind

Abstract We report a patient, PP, with semantic dementia who was studied longitudinally over two years. During this period she showed a progressive and profound loss of semantic memory affecting

The Selective Impairment of Semantic Memory

  • E. Warrington
  • Psychology
    The Quarterly journal of experimental psychology
  • 1975
Evidence is presented that this impairment of semantic memory cannot be accounted for by intellectual impairment, sensory or perceptual deficits, or expressive language disorder, and some tentative evidence for the structural basis for a hierarchically organized modality-specific semantic memory system is discussed.

Systematicity and specialization in semantics

A distributed connectionist simulation is presented in which optic aphasia occurs following damage as a result of more graded representational specialization, raising the possibility that much of the structure of the lexical/semantic system can be derived from general learning principles and need not be assumed a priori.

No Right to Speak? The Relationship between Object Naming and Semantic Impairment:Neuropsychological Evidence and a Computational Model

It is proposed that semantic impairment alone can account for the full range of word production deficits described here, on the basis of both the neuropsychological and computational evidence.

Functional Neuroanatomy of the Semantic System: Divisible by What?

Results suggest that, within a distributed conceptual system activated by words, the more prominent neural distinction relates to type of attribute, as a function of attribute type.

Systematicity and Specialization in Semantics: A Computational Account of Optic Aphasia

This work accounts for the critical aspects of optic aphasia in terms of the effects of damage to a parallel distributed processing system that maps between multiple input and output modalities and shows that the robustness of a task in such a system depends critically on its systematicity, and that modality-specific naming deficits can arise because naming is an unsystematic task.

Constraining claims about theories of semantic memory: More on unitary versus multiple semantics

Abstract In Caramazza, Hillis, Rapp, and Romani (1990) we proposed that the various patterns of impaired performance that have been used to motivate proposals of modality-specific semantics can,

Graded modality-specific specialisation in semantics: A computational account of optic aphasia

  • D. Plaut
  • Psychology
    Cognitive neuropsychology
  • 2002
The ability of the model to account for the pattern of performance observed in optic aphasia across the full range of severity of impairment provides support for the claim that semantic representations exhibit graded functional specialisation rather than being entirely amodal or modality-specific.

Connectionist Perspectives on Category-Specific Deficits

Theories of semantic memory tend between two poles. At one extreme is a view often associated with the connectionist enterprise: that the semantic system is a unitary, homogeneous mass, without