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Greta Todorova, Joseph Burling, Hongjing Lu, Frank Pollick; The importance of gaze coherence of CCTV operators in facilitating the ability to recognise harmful intentions. Journal of Vision 2017;17(10):546. doi: https://doi.org/10.1167/17.10.546.
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© ARVO (1962-2015); The Authors (2016-present)
Experienced CCTV operators are better at predicting violent behaviour than novices. It has been suggested that experienced, trained operators acquire gaze strategies to process complex visual scenes more efficiently. We examined whether the coherence of the gaze path of an operator aids in perceiving harmful intent and how this compares to the situation when coherence is altered but spatial location information is retained. To achieve this, we obtained 18 real-life surveillance videos, 16-seconds each, grouped in three categories ('fight', 'confrontation', 'play'). 'Fight' and 'confrontation' videos included aggressive behaviour, but only 'fight' videos resulted in a violent outcome (after the video ended). 'Play' videos portrayed playful behaviour without the involvement of violence. For each video, we used eye-movement data from experienced CCTV operators who successfully predicated harmful intent above chance. Naïve participants then viewed a filtered version of each video by overlaying a high resolution foveal window with a blurred periphery. Videos were filtered according to an intact gaze path from one operator or shuffled gaze locations from two operators. The shuffled gaze path was computed by alternating the two operator's eye-coordinates every 0.33 seconds. Participants viewed processed videos in both intact and shuffled conditions in two blocks. For each video, they rated the likelihood of a violent incident occurring after the video ended based on a 6-point scale. Preliminary results indicate that ratings of violent outcome are significantly greater when viewing the videos processed with the intact gaze patterns than with the shuffled gaze patterns, particularly in 'fight' and 'play' videos. This suggests that the gaze path coherence aids in perception of intent and that the spatial locations of fixations are less informative in guiding performance. Therefore, allowing novices to follow the learned gaze strategies of operators may provide effective training in improving their ability to recognise harmful intentions.
Meeting abstract presented at VSS 2017
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