title: Neural activity associated with metaphor comprehension: spatial analysis.
abstract: Though neuropsychological data indicate that the right hemisphere (RH) plays a major role in metaphor processing, other studies suggest that, at least during some phases of this processing, a RH advantage may not exist. The present study explores, through a temporally agile neural signal--the event-related potentials (ERPs)--, and through source-localization algorithms applied to ERP recordings, whether the crucial phase of metaphor comprehension presents or not a RH advantage. Participants (n=24) were submitted to a S1-S2 experimental paradigm. S1 consisted of visually presented metaphoric sentences (e.g., "Green lung of the city"), followed by S2, which consisted of words that could (i.e., "Park") or could not (i.e., "Semaphore") be defined by S1. ERPs elicited by S2 were analyzed using temporal principal component analysis (tPCA) and source-localization algorithms. These analyses revealed that metaphorically related S2 words showed significantly higher N400 amplitudes than non-related S2 words. Source-localization algorithms showed differential activity between the two S2 conditions in the right middle/superior temporal areas. These results support the existence of an important RH contribution to (at least) one phase of metaphor processing and, furthermore, implicate the temporal cortex with respect to that contribution.
authors.affiliation: Departamento de Psicología Básica, Facultad de Psicología, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Sotillo
authors.forename: Luis
authors.initials: L
authors.lastname: Carretié
authors.forename: José A
authors.initials: JA
authors.lastname: Hinojosa
authors.forename: Manuel
authors.initials: M
authors.lastname: Tapia
authors.forename: Francisco
authors.initials: F
authors.lastname: Mercado
authors.forename: Sara
authors.initials: S
authors.lastname: López-Martín
authors.forename: Jacobo
authors.initials: J
authors.lastname: Albert
mesh_terms: D000328:Adult; D000465:Algorithms; D001931:Brain Mapping; D032882:Comprehension / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D019365:Metaphor; D009474:Neurons / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology*