Orienting of attention can occur in response to various types of environmental
cues, for example, brief sudden onset events in the periphery or symbolic
directional cues such as arrows. It is now well established that observing another
person's direction of eye gaze also results in attention shifts in the corresponding direction. Such gaze-evoked attention shifts share many properties with those evoked by peripheral cues: they occur rapidly and even counter to the observer's intention. These properties are hallmarks of reflexive orienting of attention. However, gaze cueing effects differ from peripheral cueing in one central aspect. Whereas with peripheral cues, responses to targets at the cued location are inhibited at longer cue-target intervals (the inhibition of return phenomenon), no such costs have ever been observed in response to gaze cues. Instead, the early facilitation effect seems to decay.
The present series of experiments challenge this established view by
demonstrating that cueing effects can be obtained over longer intervals than
previously observed. Most importantly, these longer-term cueing effects are
inhibitory. An investigation into the form of memory mediating these longer-term gaze cueing effects suggests that they are not contingent on long-term
retrieval associated with a particular face identity. Instead, information regarding
the inhibited location appears to be maintained online in visual spatial working
memory.
Given that another person's gaze conveys a wealth of social information, one would expect that the emotional expression of a face should affect the
orienting response in the observer. However, previous research has failed to
observe such an impact of emotion on gaze cueing. The final experiments in this
thesis demonstrate emotion-specific modulations of gaze cueing at longer cue-target intervals than previously probed.
Taken together, the present investigation is an attempt to reconcile some
conflicting views in the literature. It shows that peripheral cues and gaze cues
trigger very similar behavioural effects, not only in terms of automaticity but also in terms of the basic components of orienting of attention: facilitation and
inhibition. The results of these experiments also emphasise the importance of
time-course as a variable in the study of attention processes. Finally, they
highlight the social significance of observed gaze direction and its impact on
orienting of attention in the observer.