Abstract
Visual processing has often been broken into two main pathways: one for identification of visual objects, and one for interaction with visual objects (Mishkin and Ungerleider, 1982; Goodale and Milner, 1992). Two experiments compared the effects of retrocues on different response modes which may recruit processing from different visual pathways. Each stimulus consisted of 6 colored dots placed randomly in the center of a computer screen for 1.5 seconds. An auditory retrocue for the color of one dot was presented either simultaneously with the visual stimulus, immediately after the stimulus vanished, or 2 seconds later. In some trials, the auditory cue was non-informative and served as a control condition. Approximately 4 seconds after the visual stimulus was presented, participants were shown five of the original dots and asked to indicate where the missing dot was. In experiment 1, to identify the location, participants were instructed to enter the x and y axes’ labels that indicated the location of the missing dot on a grid. In experiment 2, an interaction experiment, participants were asked to move the mouse to place the cursor at the location of the missing dot. Compared to the control condition, retrocues only improved accuracy in the identification response mode experiment, but not in the interaction experiment. The results cannot be due solely to movement interfering with the spatial memory representation since the accuracy in experiment 2 was higher than that in experiment 1. These results corroborate previous experiments, in which color retrocues improved accuracy on a shape change detection task when the retrocues indicated which part of the shape would change (Patterson & Neo, 2008). Thus, these results suggest humans may be limited in their ability to flexibly alter attention within memory depending on the type of response and which visual pathways are recruited.
Meeting abstract presented at VSS 2012