Investigating the grounding of abstract concepts in experiential, magnitude related brain networks

• Applicant: Dr. Marta Virginia Ghio, Ph.D.
• Subject Area: Biological Psychology and Cognitive Neuroscience
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 518509586

Semantic memory refers to the capacity of the brain to store general knowledge about the world in the form of concepts and flexibly recollect it. Such knowledge concerns physical entities, which we experience through our sensorimotor systems and are referred to by concrete words (e.g., nutcracker, giraffe) as well as nonphysical entities, which we refer to by abstract words (e.g., peace, infinity). In the last forty years, cognitive and neuroscience research focused on concrete concepts and provided evidence that these are represented along multiple semantic dimensions (e.g., visual, motor), which are derived from our multimodal experience with the concepts’ referents and grounded in sensorimotor systems. A challenge for current research on semantic memory is the neural representation and processing of abstract concepts. The hypothesis that, like concrete concepts, abstract concepts are (at least partially) grounded in brain systems according to their associated experiential information has been so far tested considering emotional and social experience as the dominant sources of information. There is initial evidence, however, that magnitude information, which can be experienced through dedicated perceptual mechanisms involving a fronto-parietal magnitude brain system, also contributes to the representation of certain abstract concepts (e.g., quantity, percentage). In this project, we use psycholinguistic and functional magnetic resonance imaging (fMRI) techniques to examine the processing of abstract concepts, targeting two goals. The first goal is to collect first-time multidimensional norms for a large set of abstract German nouns (Experiment 1), which will reflect to what extent abstract concepts are shaped by multiple experiential information, including not only emotional and social but also magnitude information. These norms will be fundamental for selecting the stimuli for the planned fMRI studies and will be made available for the scientific community. The second goal is to unravel the neural correlates of abstract concepts by carrying out two fMRI studies that systematically consider the multidimensionality of the semantic space, with a focus on the so far neglected magnitude dimension. In Experiment 2, we will apply a data-driven approach based on Experiment 1 to select concepts for which the magnitude and social dimension is dominant, respectively. Univariate analyses on fMRI data will reveal where these concepts are represented in the brain, while multivariate representational similarity analysis will provide novel data about how these concepts are neurally represented. In Experiment 3, we will apply univariate and multivariate analyses to fMRI data to examine whether processing abstract words referring to size, numerosity and math concepts relies on common as well as distinct portions of the magnitude system, and whether the recruitment of such neural resources is affected by participants’ experience with magnitude-related knowledge.

• DFG Programme: Research Grants