Experiment 4 Dot probe design实验4点探针的设计.docVIP

Introduction to Chapter 3 The experiments in Chapter 2 were designed to investigate whether the presence of an upright face might capture and hence bias the early allocation of visual attention to its spatial proximity. In order to determine this, we tested participants on a task that relied heavily on visual spatial attention, in the peripheral presence/absence of an upright face. A significant performance decrement on the primary task, in the presence of an upright face would have supported the claim that faces captured visual-spatial attention (cf. de Gelder Rouw, 2001). However, the consistent finding across all the four experiments showed that the orientation of a face-distractor had no impact on how well participants performed on the visual search task. In this chapter, a different visual attention paradigm is used to confirm whether an upright face’s inability to capture attention is isolated only to that used in visual search processes, or if it is a general rule. Furthermore, the experiment reported here addresses certain limitations of the general experimental design that the experiments in Chapter 2 were based upon. In the concluding section of Chapter 2, it was suggested that upright faces might be able to exert exogenous control in the absence of any endogenous control of attention. The attentional literature contains a dichotomy of exogenous and endogenous attention (e.g. {Corbetta, 2002 #85}. The former is said to be stimulus-driven and the latter, goal-directed. Having an goal-directed course of action such as a well-defined search-region or target object-category, could have had an over-riding effect over any exogenous control that upright faces might have exerted on attention (e.g. {Yantis, 1990 #115}.This could explain why upright faces failed to capture spatial attention and hence, disrupt the visual search process in the experiments reported in Chapter 2. If upright faces capture visual-spatial attention, it might only do so if doing so is no