Stroop-like interference in chess players' imagery: An unexplored possibility to be revealed by the adapted moving-spot task

Summary A group of highly skilled chess players and two control groups of subjects (nonskilled players and nonplayers) participated in a moving-spot task (cf. Attneave & Curlee, 1983). They had to move either a spot or one of several chess pieces within an imaginary grid according to instructions given by the experimenter (the imaginary motion of the imaginary object consisted of a quasirandom sequence of steps in the direction — up, right, left, or down). The general findings were as follows: (1) chess players' error rates were lower than those in the nonplayer group; (2) in a moving-spot condition there were no significant differences in the efficiency of skilled vs. nonskilled player groups; (3) in a moving chess-piece condition, ranges of spatial errors differed for chess-player and nonplayer groups, depending on the symbolic meaning of the chess pieces in the former group; (4) in a moving chess-piece condition we also found tendencies for Stroop-like interference in the group of skilled players (e. g., bishop moving illegally up, right, etc.); (5) all groups benefitted from the use of a checkerboard instead of an 8 × 8 grid as the imaginary spatial framework within which to move a piece; (6) thepost hoc analysis showed that the two small selected subgroups of subjects comprising those who used either pure visual strategy or pure chess-annotation strategy were susceptible to some Stroop-like interference and that the set of pieces with the highest incongruity of moves (bishop, knight) yielded higher error rates than the set of pieces that had congruity of moves (king, rook). Taken together, these results seem to indicate that visuospatial tasks like Attneave and Curlee's (1983) moving-spot task are performed neither on the basis of a static picture-in-the-head type of visual image, for which it is just the same whether one or another type of piece is imaginarily moved, nor on the basis of purely symbolic or propositional operations that bear no relation to the visual-configurational and spatial-localizational representations. Imagery seems to constitute a dynamicprocess of interplay between visuospatial and verbal-propositional codes.