1 Decision Neuroscience Laboratory, University of Illinois, Urbana, IL, USA2 Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, IL, USA3 Department of Internal Medicine, University of Illinois, Champaign, IL, USA4 Department of Psychology, University of Illinois, Champaign, IL, USA5 Department of Speech and Hearing Science, University of Illinois, Champaign, IL, USA6 Neuroscience Program, University of Illinois, Urbana, IL, USA
7 Universidad Autónoma de Madrid, Fundación CIEN/Fundación Reina Sofía, Madrid, Spain
8 Traumatic Brain Injury Research Laboratory, Rehabilitation Institute of Chicago, IL, USA
Discourse comprehension is a hallmark of human social behaviour and refers to the act of interpreting a written or spoken message by constructing mental representations that integrate incoming language with prior knowledge and experience. Here, we report a human lesion study (n = 145) that investigates the neural mechanisms underlying discourse comprehension (measured by the Discourse Comprehension Test) and systematically examine its relation to a broad range of psychological factors, including psychometric intelligence (measured by the Wechsler Adult Intelligence Scale), emotional intelligence (measured by the Mayer, Salovey, Caruso Emotional Intelligence Test), and personality traits (measured by the Neuroticism-Extraversion-Openness Personality Inventory). Scores obtained from these factors were submitted to voxel-based lesion-symptom mapping to elucidate their neural substrates. Stepwise regression analyses revealed that working memory and extraversion reliably predict individual differences in discourse comprehension: higher working memory scores and lower extraversion levels predict better discourse comprehension performance. Lesion mapping results indicated that these convergent variables depend on a shared network of frontal and parietal regions, including white matter association tracts that bind these areas into a coordinated system. The observed findings motivate an integrative framework for understanding the neural foundations of discourse comprehension, suggesting that core elements of discourse processing emerge from a distributed network of brain regions that support specific competencies for executive and social function.