Fusiform Face Area in Chess Expertise

Fusiform Face Area in Chess Expertise Merim Bilalic (merim.bilalic@med.uni-tuebingen.de) Department of Neuroradiology, Hoppe-Seyler Str. 2 Tubingen, 72076, Germany Abstract The ability to recognize faces is arguably one of the most important and most practiced skills. The possible functions of the fusiform face area (FFA), generally believed to be responsible for face recognition, also feature these two characteristics. On the one hand, there are claims that the FFA has evolved into a face specific module due to great importance of face processing. On the other, the FFA is seen as a general visual expertise module that distinguishes between individual examples within a single category. The previous studies used experts and novices on stimuli such as cars, birds or butterflies with ambiguous results. Here this research stream is extended to the game of chess, which does not share visible features with faces. The first study shows that chess expertise modulates the FFA activation when complex multi-object chess positions were presented. In contrast, isolated single chess objects did not produce different activation patterns among experts and novices. The second study confirmed that even a couple of isolated objects do not differently engage the FFA among experts and novices. The two studies provide support for the general expertise view of the FFA function, but also extend the scope of our understanding about the function of the FFA. The FFA does not merely distinguish between different exemplars. It also seems to engage into parsing complex multi-object stimuli that contain numerous functional and spatial relations. Keywords: face perception; expertise; pattern cognition; chess; fMRI. Introduction Faces are arguably the most important and most practiced stimuli. We start practicing face perception from our early moments and we are highly dependent on correctly distinguishing individual faces. It is fitting that the proposed functions of the fusiform face area (FFA), possibly the most important brain area in face perception, center on these two characteristics: importance and practice. On the one side, we have researchers who believe the FFA, due to, among other things, its importance in our lives, has evolved into a brain module exclusively specialized for perception of faces (Kanwisher, McDermott, & Chun, 1997; Kanwisher & Yovel, 2006). On the other side, in contrast to this face- specificity hypothesis, we have researchers that advance the claim that the FFA is a general expertise module (Gauthier, Skudlarski, Gore, & Anderson, 2000; Gauthier, Tarr, Anderson, Skudlarski, & Gore, 1999). According to the expertise hypothesis, the FFA is responsible for perceptual processes associated with differentiating among different objects within a single category stimulus (e.g., visual individuation), without regard of the type of stimuli. We investigated the expertise hypotheses using the game of chess as a model for visual expertise. The neural basis of face perception has been extensively investigated (for a review, see Kanwisher & Yovel, 2006). Different category types have been used to investigate the expertise hypothesis, ranging from birds (Gauthier et al., 2000), cars (Gauthier et al., 2000; Gilaie-Dotan, Harel, Bentin, Kanai, & Rees, 2012; Grill-Spector, Knouf, & Kanwisher, 2004; McGugin, Gatenby, Gore, & Gauthier, 2012; Xu, 2005), butterflies (Rhodes, Byatt, Michie, & Puce, 2004), to novel object types (Gauthier et al., 1999). The results are mixed and their interpretation has been the focus of an extensive debate (Bukach, Gauthier, & Tarr, 2006; Nancy Kanwisher & Yovel, 2006; Op de Beeck & Baker, 2010). Among factors complicating the interpretation is the visual similarity between faces and other categories employed – cars, birds, and even butterflies all have face- like features (Kanwisher & Yovel, 2006). The game of chess offers a way around the resemblance problem. Chess entails both individual objects and complex “chess positions” made out of individual objects. None of chess objects resemble faces and chess positions do not have much in common with face, at least not at the superficial perceptual level. Individual chess objects can be, however, differentiated just like individual faces. Expert chess players have accumulated extensive knowledge about chess objects and are quicker in recognizing them as well as their relations than novice chess players (Bilalic, Kiesel, Pohl, Erb, & Grodd, 2011; Kiesel, Kunde, Pohl, Berner, & Hoffmann, 2009; Saariluoma, 1995). The real (chess) expertise lies, however, in using knowledge to quickly size the gist of chess positions (Bilalic, Langner, Erb, & Grodd, 2010; Bilalic, Turella, Campitelli, Erb, & Grodd, 2012; Gobet & Simon, 1996). This expertise process of automatically parsing complex multi-object environment bears similarity to that found in face perception. Both processes are automatic, quick, and efficient in binding individual features into meaningful units. These characteristics make chess a suitable domain for investigation of the FFA expertise hypothesis. A recent study showed that expertise in chess is negatively correlated with the performance on face perception (Boggan, Bartlett, & Krawczyk, 2012). One possible interpretation would be that both skills engage similar processes that compete for the resources in the same brain areas. Indeed, we (Bilalic, Langner, Ulrich, & Grodd, 2011) recently showed that chess expertise mediates the activation in the FFA regardless of the task (domain specific or not) as long as the stimuli