DISPLAY DENSITY INFLUENCES VISUAL-SEARCH FOR CONJUNCTIONS OF MOVEMENTAND ORIENTATION

J. Driver and P. McLeod (1992) reported that the ease of visual search for targets defined by a conjunction of movement and orientation was affected by an interaction between target movement and target-nontarge t discriminability. When the orientation discrimination to distinguish target from nontarget was difficult, stationary targets were easier t o find than moving targets. But when the orientation discrimination to distinguish target from nontarget was easy, moving targets were easie r to find than stationary targets. H. J. Muller and J. Maxwell (1993) repeated the experiment but failed to find the interaction. The author s show that the difference between these results was due to the densit y of the visual displays used. With a high-density display, the author s replicate Driver and McLeod's result; with a low-density display, th ey replicate Muller and Maxwell's result.