Longer fixation duration while viewing face images

The spatio-temporal properties of saccadic eye movements can be influenced by the cognitive demand and the characteristics of the observed scene. Probably due to its crucial role in social communication, it is argued that face perception may involve different cognitive processes compared with non-face object or scene perception. In this study, we investigated whether and how face and natural scene images can influence the patterns of visuomotor activity. We recorded monkeys’ saccadic eye movements as they freely viewed monkey face and natural scene images. The face and natural scene images attracted similar number of fixations, but viewing of faces was accompanied by longer fixations compared with natural scenes. These longer fixations were dependent on the context of facial features. The duration of fixations directed at facial contours decreased when the face images were scrambled, and increased at the later stage of normal face viewing. The results suggest that face and natural scene images can generate different patterns of visuomotor activity. The extra fixation duration on faces may be correlated with the detailed analysis of facial features

The effect of the first glimpse at a scene on eye movements during search

Previewing scenes briefly makes finding target objects more efficient when viewing is through a gaze-contingent window (windowed viewing). In contrast, showing a preview of a randomly arranged search display does not benefit search efficiency when viewing during search is of the full display. Here, we tested whether a scene preview is beneficial when the scene is fully visible during search. Scene previews, when presented, were 250 ms in duration. During search, the scene was either fully visible or windowed. A preview always provided an advantage, in terms of decreasing the time to initially fixate and respond to targets and in terms of the total number of fixations. In windowed visibility, a preview reduced the distance of fixations from the target position until at least the fourth fixation. In full visibility, previewing reduced the distance of the second fixation but not of later fixations. The gist information derived from the initial glimpse of a scene allowed for placement of the first one or two fixations at information-rich locations, but when nonfoveal information was available, subsequent eye movements were only guided by online informatio

Saccade control in natural images is shaped by the information visible at fixation: evidence from asymmetric gaze-contingent windows

When people view images, their saccades are predominantly horizontal and show a positively skewed distribution of amplitudes. How are these patterns affected by the information close to fixation and the features in the periphery? We recorded saccades while observers encoded a set of scenes with a gaze-contingent window at fixation: Features inside a rectangular (Experiment 1) or elliptical (Experiment 2) window were intact; peripheral background was masked completely or blurred. When the window was asymmetric, with more information preserved either horizontally or vertically, saccades tended to follow the information within the window, rather than exploring unseen regions, which runs counter to the idea that saccades function to maximize information gain on each fixation. Window shape also affected fixation and amplitude distributions, but horizontal windows had less of an impact. The findings suggest that saccades follow the features currently being processed and that normal vision samples these features from a horizontally elongated region

Scrambled eyes? Disrupting scene structure impedes focal processing and increases bottom-up guidance

Previous research has demonstrated that search and memory for items within natural scenes can be disrupted by ?scrambling? the images. In the present study, we asked how disrupting the structure of a scene through scrambling might affect the control of eye fixations in either a search task (Experiment 1) or a memory task (Experiment 2). We found that the search decrement in scrambled scenes was associated with poorer guidance of the eyes to the target. Across both tasks, scrambling led to shorter fixations and longer saccades, and more distributed, less selective overt attention, perhaps corresponding to an ambient mode of processing. These results confirm that scene structure has widespread effects on the guidance of eye movements in scenes. Furthermore, the results demonstrate the trade-off between scene structure and visual saliency, with saliency having more of an effect on eye guidance in scrambled scenes