The line-in-object superiority effect in perception: It depends on where you fix your eyes and what is located at the point of fixation

Williams and Weisstein (1978) reported that briefly presented line elements could be more accurately discerned in three-dimensional, coherent contexts than when presented alone. A series of five studies investigated this effect. The first study demonstrated that the general assumption that three-dimensional and coherent contexts are necessary conditions for demonstrating a line-in-object superiority effect is in error, and a robust effect can be demonstrated with contexts lacking coherence and depth. The remaining studies focused on a potentially more important determinant of the line-in-object effect. Evidence is presented that whether a given context facilitates, impairs, or has no effect on line detection is determined by the location of the fixation point and the amount of line detail at the fixation point. Proposals outlining processes assumed to underlie this fixation-location effect are advanced.