Our object recognition abilities, a direct product of our experience with objects, are fine-tuned to perfection. Left temporal and lateral areas along the dorsal, action related stream, as well as left infero-temporal areas along the ventral, object related stream are engaged in object recognition. Here we show that expertise modulates the activity of dorsal areas in the recognition of man-made objects with clearly specified functions. Expert chess players were faster than chess novices in identifying chess objects and their functional relations. Experts' advantage was domain-specific as there were no differences between groups in a control task featuring geometrical shapes. The pattern of eye movements supported the notion that experts' extensive knowledge about domain objects and their functions enabled superior recognition even when experts were not directly fixating the objects of interest. Functional magnetic resonance imaging (fMRI) related exclusively the areas along the dorsal stream to chess specific object recognition. Besides the commonly involved left temporal and parietal lateral brain areas, we found that only in experts homologous areas on the right hemisphere were also engaged in chess specific object recognition. Based on these results, we discuss whether skilled object recognition does not only involve a more efficient version of the processes found in non-skilled recognition, but also qualitatively different cognitive processes which engage additional brain areas.
Friday, February 04, 2011
Skilled object recognition uses both our left and right hemispheres
Bilalić et al. make the interesting observation that skilled chess players, while no faster or better than amateurs at geometric object recognition (which mainly engages left hemisphere), are more rapid than amateurs at identifying chess positions, while at the same time engaging additional areas of their right hemisphere. This expanded use of brain areas requires extensive training. (When the subjects were shown the chess diagrams, the novices looked directly at the pieces to recognize them, while the experts looked on the middle of the boards and took everything in with their peripheral vision.) (Wan et al. report a similar study in Japan examining experts in shogi, a game similar to chess. It highlights further brain areas involved in expertise.) Here is the Bilalić et al. abstract (dorsal means along the upper part of the brain, ventral is lower):