Chapters 5, 6, & 7: Eye Gaze and Visual Working Memory Encoding 1 Summary

In Chapters 6 and 7, I examined the possibility that observation of others‘ eye gaze affects participants‘ visual working memory encoding. In Chapter 6, I tested whether agents‘ object-oriented gaze might lead to binding of agents and objects in

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visual working memory encoding. The current findings, however, revealed pair-wise encoding of agents and objects that was not sensitive to agents‘ gaze directions. In Chapter 7, I further examined the role of agents‘ object-oriented gaze with a further change detection paradigm that comprised a shorter temporal sequence and no spatial pairing cue. However, once again findings revealed that mere observation of agents‘ object-oriented gaze does not affect participants‘ encoding of agents and objects. The other hypothesis in Chapter 7 was that participants‘ encoding might be disrupted when agents directly look out at them, even when agents‘ gaze directions were not relevant to participants‘ encoding task. It was found that, as hypothesised, when the agents gazed directly towards participants, participants‘ encoding performance was considerably worse than when the agents gazed in other directions. Moreover, although participants appeared unable to employ a top-down strategy to avoid the hindering effect of participant-oriented gaze, bottom-up visual input did facilitate participants‘ recovery to normal encoding. The current investigations implicated participant-oriented gaze in visual working memory encoding but indicated a minimum role for others‘ object-oriented gaze in such processes. In the following section I shall explore some factors that may have shaped the present findings of a minimal effect of agents‘ object-oriented gaze.

8.3.2 Visual Working Memory as a Measure of Social Perception: Factors to Consider for Further Experiments

As described in Chapter 5, much evidence demonstrates automatic attention shifting in response to the observation of others‘ eye gaze (e.g., Driver et al., 1999). The current investigation extended the examination of automatic attention shifting to examine whether the automatic processing of others‘ gaze affects individuals‘ performance on visual working memory tasks. Results across two different change

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detection paradigms suggest that the lack of effect of agents‘ object-oriented gaze on participants‘ encoding performance is not due to the specific temporal sequence or spatial pairing cue used. There are, however, a number of other factors that may account for the minimal effect of agents‘ object-oriented gaze, and which could be considered when carrying out further examinations. Firstly, throughout Chapters 6 and 7, the distances between the agents and the objects gazed upon by the agents were designed to have minimal contribution towards any binding that might be observed (i.e., all agents and objects are equally distant from one another). One possibility is that in order to achieve integration of agent and object information, it is necessary that the agent object pairings are spatially close to one another. Roberts and Humphreys (in prep) found that the binding of congruently paired actions and objects required the stimuli to be in close proximity to one another. Xu (2006) also found that object-parts presented in close proximity to one another are bound together more easily than object-parts that are further apart from one another. Hence, further manipulations of the proximity between agents and objects may provide more optimised parameters for the observation of binding.

Secondly, in the current design, the differences in agents‘ gaze directions (either gaze towards objects or gaze away from objects) have never been presented in a single display. Participants only observe agents‘ varied gaze directions either between trials (Experiments 6, 7, and 9b) or across different displays within the same trial (Experiment 8). This is dissimilar to studies that employed flicker change

detection paradigm (Freeth, Ropar, Chapman, & Mitchell, 2010; Langton et al., 2006). In these studies, participants observe an agent looking towards one particular object amongst an array of objects. This allows presentation of the agent‘s gaze towards and gaze away from objects within a single display, providing a stronger

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contrast of different types of agent and object relationships than the current design. It is possible that the contrast of agents‘ varied gaze directions within a single display may facilitate the observation of a binding effect sensitive to agents‘ gaze directions.

Thirdly, the experiments reported in Chapters 6 and 7 presented agents

positioned in the lateral regions of the visual field. We know that when healthy adults make speeded judgements about the gaze directions displayed by a central face stimulus, their responses are unaffected by the gaze directions of a secondary distracting face stimulus presented in peripheral position (Burton, Bindemann, Langton, Schweinberger, & Jenkins, 2009). This suggests that automatic processing of eye gaze is likely to require the stimuli to be in the focus of attention, and that positioning the face stimuli centrally helps achieve this. Studies that have

demonstrated automatic gaze processing (e.g., Frischen et al., 2007; Langton et al., 2006) also position the avatars in the centre of the displays. Further examination of agents‘ object-oriented gaze could benefit from positioning the avatars centrally in the field of vision.

Further investigations notwithstanding, Chapters 6 and 7 provide a systematic examination of the possible effect of agents‘ object-oriented gaze on visual working memory encoding. The finding that participant-oriented gaze impairs visual working memory, suggests that automatic processing of agents‘ gaze may affect performances beyond those that concern one‘s allocation of attention. Furthermore, as previously mentioned, there are common features amongst individuals‘ automatic processing of various social perceptual cues in the environment (e.g., eye gaze and stereotypic attributes). I will discuss these findings along with the relevant findings from Chapters 3 and 4 in the following sections.