Neural basis of category-specific semantic deficits for living things: Evidence from semantic dementia, HSVE and a neural network model

Matthew A. Lambon Ralph, Christine Lowe, Timothy T Rogers

    Research output: Contribution to journalArticlepeer-review

    308 Downloads (Pure)

    Abstract

    Studies of patients with semantic impairments following brain damage offer key insights into the cognitive and neural organization of semantic memory. Especially important in this regard are studies of category-specific semantic impairment. We report a direct comparison of semantic deficits in two groups suffering from different diseases: semantic dementia (SD) and herpes simplex virus encephalitis (HSVE). Although pathology in both disorders is centred on the anterior temporal lobes bilaterally, category-specific semantic impairment is rarely observed in SD yet commonly found in HSVE. Using a combination of neuropsychology and computational neuroscience, we tested the possibility that category-specific deficits for living things depend not solely upon the location of damage within the cortical semantic network but also critically upon the type of impairment. When the semantic representations within the model are degraded or 'dimmed' then a generalized, global semantic impairment results (as found in SD) but when the representations are distorted then a category-specific pattern emerges (as per HSVE). Three novel predictions from this model were tested and confirmed, thereby adding weight to the hypothesis that both type and distribution of pathology can be critical in producing neuropsychological phenomena. © The Author (2007). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved.
    Original languageEnglish
    Pages (from-to)1127-1137
    Number of pages10
    JournalBrain
    Volume130
    Issue number4
    DOIs
    Publication statusPublished - Apr 2007

    Keywords

    • Category-specific disorders
    • Herpes simplex virus encephalitis
    • PDP neural network models
    • Semantic dementia
    • Semantic memory disorders

    Fingerprint

    Dive into the research topics of 'Neural basis of category-specific semantic deficits for living things: Evidence from semantic dementia, HSVE and a neural network model'. Together they form a unique fingerprint.

    Cite this