title: Analogical reasoning and prefrontal cortex: evidence for separable retrieval and integration mechanisms.
abstract: The present study examined the contributions of prefrontal cortex (PFC) subregions to two component processes underlying verbal analogical reasoning: semantic retrieval and integration. Event-related functional magnetic resonance imaging data were acquired while subjects performed propositional analogy and semantic decision tasks. On each trial, subjects viewed a pair of words (pair 1), followed by an instructional cue and a second word pair (pair 2). On analogy trials, subjects evaluated whether pair 2 was semantically analogous to pair 1. On semantic trials, subjects indicated whether the pair 2 words were semantically related to each other. Thus, analogy--but not semantic--trials required integration across multiple retrieved relations. To identify regions involved in semantic retrieval, we manipulated the associative strength of pair 1 words in both tasks. Anterior left inferior PFC (aLIPC) was modulated by associative strength, consistent with a role in controlled semantic retrieval. Left frontopolar cortex was insensitive to associative strength, but was more sensitive to integration demands than was aLIPC, consistent with a role in integrating the products of semantic retrieval to evaluate whether distinct representations are analogous. Right dorsolateral PFC exhibited a profile consistent with a role in response selection rather than retrieval or integration. These findings indicate that verbal analogical reasoning depends on multiple, PFC-mediated computations.
authors.affiliation: Department of Psychology and Center for Mind and Brain, University of California at Davis, Davis, CA 95616, USA. Sabunge@ucdavis.edu
authors.forename: Silvia A
authors.initials: SA
authors.lastname: Bunge
authors.forename: Carter
authors.initials: C
authors.lastname: Wendelken
authors.forename: David
authors.initials: D
authors.lastname: Badre
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Wagner
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D003071:Cognition / Q000502:physiology*; D003210:Concept Formation / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology; D011939:Mental Recall / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D011340:Problem Solving / Q000502:physiology*; D012659:Semantic Differential; D013647:Task Performance and Analysis; D014163:Transfer, Psychology / Q000502:physiology