TY - JOUR
T1 - Fine-coarse semantic processing in schizophrenia
T2 - A reversed pattern of hemispheric dominance
AU - Zeev-Wolf, Maor
AU - Goldstein, Abraham
AU - Levkovitz, Yechiel
AU - Faust, Miriam
N1 - Funding Information: This paper is based on a thesis written by the first author and supervised by two of the authors (Abraham Goldstein and Miriam Faust), submitted to Bar-Ilan University in partial fulfilment of the requirements toward a Ph.D. degree. The work was supported by the I-CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation (grant No. 51/11 ).
PY - 2014/1/1
Y1 - 2014/1/1
N2 - Left lateralization for language processing is a feature of neurotypical brains. In individuals with schizophrenia, lack of left lateralization is associated with the language impairments manifested in this population. Beeman[U+05F3]s fine-coarse semantic coding model asserts left hemisphere specialization in fine (i.e., conventionalized) semantic coding and right hemisphere specialization in coarse (i.e., non-conventionalized) semantic coding. Applying this model to schizophrenia would suggest that language impairments in this population are a result of greater reliance on coarse semantic coding. We investigated this hypothesis and examined whether a reversed pattern of hemispheric involvement in fine-coarse semantic coding along the time course of activation could be detected in individuals with schizophrenia.Seventeen individuals with schizophrenia and 30 neurotypical participants were presented with two word expressions of four types: literal, conventional metaphoric, unrelated (exemplars of fine semantic coding) and novel metaphoric (an exemplar of coarse semantic coding). Expressions were separated by either a short (250. ms) or long (750. ms) delay.Findings indicate that whereas during novel metaphor processing, controls displayed a left hemisphere advantage at 250. ms delay and right hemisphere advantage at 750. ms, individuals with schizophrenia displayed the opposite. For conventional metaphoric and unrelated expressions, controls showed left hemisphere advantage across times, while individuals with schizophrenia showed a right hemisphere advantage. Furthermore, whereas individuals with schizophrenia were less accurate than control at judging literal, conventional metaphoric and unrelated expressions they were more accurate when judging novel metaphors.Results suggest that individuals with schizophrenia display a reversed pattern of lateralization for semantic coding which causes them to rely more heavily on coarse semantic coding. Thus, for individuals with schizophrenia, speech situation are always non-conventional, compelling them to constantly seek for meanings and prejudicing them toward novel or atypical speech acts. This, in turn, may disadvantage them in conventionalized communication and result in language impairment.
AB - Left lateralization for language processing is a feature of neurotypical brains. In individuals with schizophrenia, lack of left lateralization is associated with the language impairments manifested in this population. Beeman[U+05F3]s fine-coarse semantic coding model asserts left hemisphere specialization in fine (i.e., conventionalized) semantic coding and right hemisphere specialization in coarse (i.e., non-conventionalized) semantic coding. Applying this model to schizophrenia would suggest that language impairments in this population are a result of greater reliance on coarse semantic coding. We investigated this hypothesis and examined whether a reversed pattern of hemispheric involvement in fine-coarse semantic coding along the time course of activation could be detected in individuals with schizophrenia.Seventeen individuals with schizophrenia and 30 neurotypical participants were presented with two word expressions of four types: literal, conventional metaphoric, unrelated (exemplars of fine semantic coding) and novel metaphoric (an exemplar of coarse semantic coding). Expressions were separated by either a short (250. ms) or long (750. ms) delay.Findings indicate that whereas during novel metaphor processing, controls displayed a left hemisphere advantage at 250. ms delay and right hemisphere advantage at 750. ms, individuals with schizophrenia displayed the opposite. For conventional metaphoric and unrelated expressions, controls showed left hemisphere advantage across times, while individuals with schizophrenia showed a right hemisphere advantage. Furthermore, whereas individuals with schizophrenia were less accurate than control at judging literal, conventional metaphoric and unrelated expressions they were more accurate when judging novel metaphors.Results suggest that individuals with schizophrenia display a reversed pattern of lateralization for semantic coding which causes them to rely more heavily on coarse semantic coding. Thus, for individuals with schizophrenia, speech situation are always non-conventional, compelling them to constantly seek for meanings and prejudicing them toward novel or atypical speech acts. This, in turn, may disadvantage them in conventionalized communication and result in language impairment.
KW - Hemispheres
KW - Metaphor comprehension
KW - Schizophrenia
KW - Semantic processing
KW - Split-visual field
UR - http://www.scopus.com/inward/record.url?scp=84893481141&partnerID=8YFLogxK
U2 - 10.1016/j.neuropsychologia.2014.01.008
DO - 10.1016/j.neuropsychologia.2014.01.008
M3 - Article
C2 - 24462952
SN - 0028-3932
VL - 56
SP - 119
EP - 128
JO - Neuropsychologia
JF - Neuropsychologia
IS - 1
ER -