Poster D46, Monday, March 27, 8:00 – 10:00 am, Pacific Concourse
Decoding rule modality in the human left inferior frontal gyrus
Michele Furlan1, Laura Babcock2, Antonino Vallesi1; 1Department of Neuroscience, University of Padua, Padua, Italy, 2Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
Many daily activities require us to integrate information and extrapolate unknown rules, a process known as inductive reasoning. Until recently the left prefrontal cortex (PFC) was thought to integrate information across verbal patterns, but recent evidence showed that the left inferior frontal gyrus (IFG) is able to apply inductive reasoning to both verbal and spatial information. Here we used multivariate pattern classification of fMRI data to decode the representation of rule modality during different types of rule search. Thirteen participants were asked to extract the rule underlying streams of letters presented in different spatial locations. The rule was either verbal (letters forming words pertaining to a single semantic category) or spatial (letters forming geometric figures). The rule search was carried out either serially (i.e. the modality to attend was known by participants) or in parallel (i.e. the modality to attend was unknown). Our results show that information about rule modality is reliably represented in the left IFG but not in the right one, and that this representation was stronger when the modality to attend to was known in advance. These results were replicated in a second confirmation analysis run on the same participants who completed the same experiment two years after the acquisition of the first one. These findings extend our knowledge of the neural mechanisms of inductive reasoning and how relevant information is mapped on the prefrontal cortex [This project was funded by the FP7 European Research Council Starting Grant LEX-MEA (GA #313692) awarded to AV].
Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching