要旨
Introduction
It is not common to find a single region responsible for just a single class of stimuli but the fusiform face area (FFA) located on the right lateral fusiform gyrus comes close. While it is clear that the FFA is heavily involved in the recognition of faces, it is not clear whether it is exclusively devoted to just a single calls of stimuli. The most prominent alternative explanations states that the FFA is involved in all within class discrimination. This ‘expertise’ hypothesis has been tested with bird, car, and butterfly experts with mixed results. Due to the nature of the expertise domains employed, in most cases a recognition paradigm was used. Chess, however, offers an ideal test not only for recognition but also for other complex tasks that characterize expertise. Chess has often been used in cognitive science because of its simple and controlled nature, on the one side, and complexity and ecologically validity, on the other. Here we show that chess can also inform the contraversy in neuroscience too.
Methods
Two groups of chess players, experts and novices, were presented with two experiments while fMRI images were acquired with a 3T Siemens Trio scanner. In the first recognition experiment the players had to indicate whether the current stimulus was the same as the previously seen stimulus. There were two stimuli classes (chess and faces) which were presented in two positions (normal and inverted). The second experiment there were three different tasks a) check task where one had to indicate whether Black gives check, b) knight task where one had to indicate if two knights of different colours were present, and c) dot task where players had to indicate if two dot of different colours were present. Two kinds of stimuli were used a) chess position with meaning and b) chess position with no-meaning where the pieces were randomly scattered. Before the actual experiments, players had seen a localizer task (faces and objects) which was used to localize the right FFA in individual players. These individual FFAs are then used in the analysis of the two experiments.
Results
FFA was more activated when players dealt with faces in the first recognition experiment than with chess while experts showed more activation than novices only with chess stimuli (Figure 1). There were no differences in the activation of FFA in players across three differently complex tasks in the second experiment. Experts did, however, display more activation than novices in all three tasks (Figure 2).
Conclusions
FFA was more activated in experts than in novices across all domain specific chess tasks which imply that the FFA is involved in chess expertise. FFA did not play a role, however, when experts could use their knowledge (meaning vs no-meaning) in the second experiment. FFA may be generally more activated in experts than novices even in the face specific tasks, but it does not help in the utilization of chess knowledge, the most important aspect of chess expertise.
