title: Conditional and syllogistic deductive tasks dissociate functionally during premise integration.
abstract: Deduction allows us to draw consequences from previous knowledge. Deductive reasoning can be applied to several types of problem, for example, conditional, syllogistic, and relational. It has been assumed that the same cognitive operations underlie solutions to them all; however, this hypothesis remains to be tested empirically. We used event-related fMRI, in the same group of subjects, to compare reasoning-related activity associated with conditional and syllogistic deductive problems. Furthermore, we assessed reasoning-related activity for the two main stages of deduction, namely encoding of premises and their integration. Encoding syllogistic premises for reasoning was associated with activation of BA 44/45 more than encoding them for literal recall. During integration, left fronto-lateral cortex (BA 44/45, 6) and basal ganglia activated with both conditional and syllogistic reasoning. Besides that, integration of syllogistic problems additionally was associated with activation of left parietal (BA 7) and left ventro-lateral frontal cortex (BA 47). This difference suggests a dissociation between conditional and syllogistic reasoning at the integration stage. Our finding indicates that the integration of conditional and syllogistic reasoning is carried out by means of different, but partly overlapping, sets of anatomical regions and by inference, cognitive processes. The involvement of BA 44/45 during both encoding (syllogisms) and premise integration (syllogisms and conditionals) suggests a central role in deductive reasoning for syntactic manipulations and formal/linguistic representations.
authors.affiliation: Department of Psychology, Università Milano - Bicocca, Milano, Italy. carlo.reverberi@unimib.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Reverberi
authors.forename: Paolo
authors.initials: P
authors.lastname: Cherubini
authors.forename: Richard S J
authors.initials: RS
authors.lastname: Frackowiak
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
authors.forename: Eraldo
authors.initials: E
authors.lastname: Paulesu
authors.forename: Emiliano
authors.initials: E
authors.lastname: Macaluso
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D013850:Thinking / Q000502:physiology*