title: Emotional and cognitive stimuli differentially engage the default network during inductive reasoning.
abstract: The brain's default network (DN) is comprised of several cortical regions demonstrating robust intrinsic connectivity at rest. The authors sought to examine the differential effects of emotional reasoning and reasoning under certainty upon the DN through the employment of an event-related fMRI design in healthy participants. Participants were presented with syllogistic arguments which were organized into a 2 × 2 factorial design in which the first factor was emotional salience and the second factor was certainty/uncertainty. We demonstrate that regions of the DN were activated both during reasoning that is emotionally salient and during reasoning which is more certain, suggesting that these processes are neurally instantiated on a network level. In addition, we present evidence that emotional reasoning preferentially activates the dorsomedial (dMPFC) subsystem of the DN, whereas reasoning in the context of certainty activates areas specific to the DN's medial temporal (MTL) subsystem. We postulate that emotional reasoning mobilizes the dMPFC subsystem of the DN because this type of reasoning relies upon the recruitment of introspective and self-relevant data such as personal bias and temperament. In contrast, activation of the MTL subsystem during certainty argues that this form of reasoning involves the recruitment of mnemonic and semantic associations to derive conclusions.
authors.affiliation: Department of Neurology, Division of Cognitive Neurology, Beth Israel Deaconess Medical Center 330 Brookline Avenue, KS 230, Boston, MA 02215, USA. meldaief@bidmc.harvard.edu
authors.forename: Mark C
authors.initials: MC
authors.lastname: Eldaief
authors.forename: Thilo
authors.initials: T
authors.lastname: Deckersbach
authors.forename: Lindsay E
authors.initials: LE
authors.lastname: Carlson
authors.forename: Jan C
authors.initials: JC
authors.lastname: Beucke
authors.forename: Darin D
authors.initials: DD
authors.lastname: Dougherty
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D003071:Cognition / Q000502:physiology*; D003210:Concept Formation / Q000502:physiology*; D004644:Emotions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D012660:Semantics; D014705:Verbal Behavior / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen