Dissociation of visual and spatial processing in working memory.

Although models of working memory originally included visuo-spatial memory as an undifferentiated component, recent work indicates that spatial location is separable from other visual characteristics. The evidence which is derived from interference, however, typically requires the division of conscious attention between primary and interference tasks. In the present experiments the differential effects of an unattended flickering surround upon serial recall of a central stimulus presentation were investigated. Colour changes in the surround created more interference than achromatic flicker when the task was to report either the colours or the patterns presented in the target. When the locations of the targets were required, however, the situation was reversed and the achromatic flicker created more interference than did the colour flicker. It is suggested that this double dissociation of identification and location is best understood in terms of differential involvement of the magnocellular and parvocellular pathways.