Time Course of Inhibitory Control During Analogical Reasoning: An Event-Related Potential Approach

Time Course of Inhibitory Control During Analogical Reasoning: An Event-Related Potential Approach Brian M. Sweis (bsweis@luc.edu) Departments of Biology and Psychology Loyola University Chicago 1032 W Sheridan Rd Chicago, IL 60626 USA Krishna L. Bharani (kbharani@luc.edu) Department of Psychology Loyola University Chicago 1032 W Sheridan Rd Chicago, IL 60626 USA Robert G. Morrison (rmorrison@luc.edu) Department of Psychology, Neuroscience Institute Loyola University Chicago 1032 W Sheridan Rd Chicago, IL 60626 USA Abstract Inhibitory control is an important aspect of analogical reasoning critically dependent on prefrontal cortex. We used a novel visual analogy paradigm with scalp electroencephalography (EEG) to explore several ways the brain uses inhibitory control to perform analogy. Previous studies have suggested that inhibitory control helps to manage working memory, so we used a separate task to measure individual differences in working-memory span to help us interpret differences in inhibitory control during reasoning. We found evidence that low working-memory span individuals likely lacked the necessary inhibitory control to keep unattended relations from entering visuospatial working memory early in processing. We also found that a late frontal event-related potential sensitive to relational distraction was differentially modulated in high and low working memory span individuals. These findings provide additional evidence for the importance of inhibitory control during analogical processing. Keywords: analogy, working memory, inhibitory control, EEG, ERP Introduction Studies involving children (Richland, Chan, Morrison, & Au, 2010; Richland, Morrison, & Holyoak, 2006; Thibaut, French, & Vezneva, 2010a, 2010b), younger adults (Cho, Holyoak, & Cannon, 2007; Cho et al., 2010), older adults (Viskontas et al., 2004), and patients with damage to prefrontal cortex (Krawczyk et al., 2008; Morrison et al., 2004) have all provided evidence that inhibitory control in working memory (WM) is an important aspect of both visual and verbal analogical reasoning. Neuroimaging studies of analogical reasoning have implicated areas in prefrontal cortex (PFC) as critical for semantic retrieval during analogy (Bunge, Wendelken, Badre, & Wagner, 2005), avoiding distraction from non-goal related relational information (Cho et al., 2010), and performing analogical mapping and similar types of relational integration (Bunge, Helskog, & Wendelken, 2009; Cho et al., 2010; Green et al., 2010; Morrison, Nikitin, Bharani, & Doumas 2012). Computational accounts of these data (Doumas, Morrison, & Richland, under review; Knowlton, Morrison, Hummel, & Holyoak, 2012; Morrison et al., 2004; Morrison, Doumas, & Richland, 2011; Viskontas et al., 2004) suggest that inhibitory control is central to the processes of semantic retrieval and analogical mapping; however, there is little direct experimental evidence for mechanisms by which inhibitory control is recruited during analogical reasoning. WM has been thought to play a critical role during analogical reasoning (Halford, 1992; Morrison, 2005). Domain-specific as well as central-executive WM dual tasks interfere with analogical processing (Morrison, Truong, & Holyoak, 2001; Waltz, Lau, Grewal, & Holyoak, 2000). Likewise, individual differences in working-memory span (see Conway et al., 2005) are frequently related to matrix reasoning performance (e.g., Kane & Engle, 2002). In an effort to understand how inhibitory control may be involved in WM processing, Vogel, McCollough, and Machizawa (2005) asked participants with high and low WM span to perform a simple delayed match-to-sample WM task while their brain activity was observed using scalp encephalography (EEG). Vogel et al. identified a Continuous Negative Variation (CNV) event-related