Abstract
The composite paradigm is a selective attention task that measures holistic processing (HP) by assessing how well participants can selectively attend to half of an image. HP measured in this paradigm is larger for faces than other objects, and larger for aligned than misaligned test faces. Prior work has argued for a decisional component of HP because HP is affected by test but not study face configuration (aligned/misaligned) when these conditions are randomized (Richler et al., submitted). Here, using faces and novel objects (Greebles), we investigate whether study configuration exerts a contextual or strategic effect with faces and Greebles that may be uncovered by blocking study conditions. For faces, HP is modulated by test configuration, presumably because aligned faces are processed holistically as a result of expertise. However, studying misaligned items requires a wider spread of attention, so it may be difficult to subsequently narrow attention to selectively attend to half of the test item. Thus, HP of faces and Greebles may depend on the attentional context within the trial, elicited by the study configuration. Indeed, we found that blocking study configuration influenced the magnitude of HP for faces (E1). HP was also obtained in Greeble novices in a blocked design but only when study items were misaligned (E2). However, when study Greeble conditions were randomized, HP was obtained in both study conditions (E3), presumably due to the mere presence of study-misaligned trials. Furthermore, the context effect on HP for Greebles was induced by task-irrelevant faces in a dual-task paradigm (E4). Finding holistic effects under certain conditions in the randomized and dual-task designs but not blocked experiments suggests that these effects are driven by a change in strategy, not a perceptual limitation. Together, these results suggest that HP is not solely perceptual, as it can be modulated by contextually-induced strategy.
This work was funded by a grant from NSF and the James S. McDonnell Foundation.