Expertise modulates the neural basis of context dependent recognition of objects and their relations

Abstract

Recognition of objects and their relations is necessary for orienting in real life. We examined cognitive processes related to recognition of objects, their relations, and the patterns they form by using the game of chess. Chess enables us to compare experts with novices and thus gain insight in the nature of development of recognition skills. Eye movement recordings showed that experts were generally faster than novices on a task that required enumeration of relations between chess objects because their extensive knowledge enabled them to immediately focus on the objects of interest. The advantage was less pronounced on random positions where the location of chess objects, and thus typical relations between them, was randomized. Neuroimaging data related experts' superior performance to the areas along the dorsal stream-bilateral posterior temporal areas and left inferior parietal lobe were related to recognition of object and their functions. The bilateral collateral sulci, together with bilateral retrosplenial cortex, were also more sensitive to normal than random positions among experts indicating their involvement in pattern recognition. The pattern of activations suggests experts engage the same regions as novices, but also that they employ novel additional regions. Expert processing, as the final stage of development, is qualitatively different than novice processing, which can be viewed as the starting stage. Since we are all experts in real life and dealing with meaningful stimuli in typical contexts, our results underline the importance of expert-like cognitive processing on generalization of laboratory results to everyday life.

Figure 1

Design and reaction time data. A: The stimuli used in the task. Participants had to indicate whether the number of Black threats (how many times Black can take White) was four. Left side presents normal positions taken from masters games unknown to participants; right side depicts random positions obtained by distributing pieces randomly on the board. The relations are highlighted by lines between the encircled objects—not seen by participants. B: Trial structure. Baseline stimulus was an initial chess board configuration with a fixation cross; its duration was jittered. A gap in stimulus presentation was used as a warning about the upcoming stimulus. The actual chess stimulus (normal and random positions) was then presented. After the players indicated their answers by pressing one of the response buttons, the baseline stimulus of the next trial was presented. C: Time (in seconds) experts and novices took to complete the task depending on the type of position. D: Errors (in percentage) experts and novices make while completing the chess and control tasks depending on the type of position. Blue color represents experts; red color novices. Error bars indicate the standard error of the mean (SEM). *P < 0.01 in a t‐test for dependent samples.

Figure 2

Eye movement data. A: The average percentage of fixations on the objects of interest for experts and novices on normal and random positions across the whole trial. B: The average percentage of fixations on any objects irrespective of interest for experts and novices on normal and random positions across the whole trial. Blue color represents experts; red color novices. Error bars indicate SEM. *P < 0.01 in a t‐test for dependent samples.

Figure 3

Neuroimaging data (expertise effect). Brain regions more activated in experts than in novices (main effect of expertise; P < 0.05; FWE‐corrected; k = 5), presented on an inflated brain. SMG, supramarginal gyrus; POTJ, parieto‐occipito‐temporal junction; RSC, retrosplenial cortex; CoS, collateral sulcus. The MNI coordinates are presented below the ROI labels. Percent signal change (relative to starting position/baseline) from the most activated voxel in each of the regions was extracted and plotted for descriptive purposes. Blue color represents experts; red color novices. Error bars indicate SEM. *P < 0.01 in a t‐test for dependent samples.