Anticipatory Eye Movements While Watching Continuous Action Across Shots in Video Sequences: A Developmental Study

Dissociable genetic influences on eye movements during abstract versus naturalistic social scene viewing in infancy

Eye-movement metrics like fixation location and duration are increasingly being used in infancy research. We tested whether fixation durations during meaningful social stimulus viewing involve common or different familial influences than fixation durations during viewing of abstract stimulus. We analysed the duration of fixations, and the allocation of fixations to face and motion, from 536 dizygotic and monozygotic 5-month-old twins in: naturalistic scenes including low- and high-level social features, and abstract scenes only having low-level features. We observed significant genetic influences in both conditions (h2naturalistic = 0.30, 95% confidence interval (CI) 0.14 to 0.44; h2abstract = 0.25, 95% CI 0.09 to 0.39), while shared environmental influences were negligible. Although some genetic influences were shared between the two conditions, unique genetic factors were linked to naturalistic scene viewing, indicating that fixation durations index different phenomena dependent on the context. Heritability for face looking was moderate (h2 = 0.19, 95% CI 0.03 to 0.34), and no familial influences were found for motion looking. Exploratory polygenic score analyses revealed no significant associations with fixation measures. This study underscores the dissociable genetic influences on infants' visual exploration of abstract versus naturalistic stimuli and the importance of considering context when interpreting eye-tracking data.

Gaze Behavior Reveals Expectations of Potential Scene Changes

Even if the scene before our eyes remains static for some time, we might explore it differently compared with how we examine static images, which are commonly used in studies on visual attention. Here we show experimentally that the top-down expectation of changes in natural scenes causes clearly distinguishable gaze behavior for visually identical scenes. We present free-viewing eye-tracking data of 20 healthy adults on a new video dataset of natural scenes, each mapped for its potential for change (PfC) in independent ratings. Observers looking at frozen videos looked significantly more often at the parts of the scene with a high PfC compared with static images, with substantially higher interobserver coherence. This viewing difference peaked right before a potential movement onset. Established concepts like object animacy or salience alone could not explain this finding. Images thus conceal experience-based expectations that affect gaze behavior in the potentially dynamic real world.

The effect of narrative coherence and visual salience on children's and adults' gaze while watching video

Low-level visual features (e.g., motion, contrast) predict eye gaze during video viewing. The current study investigated the effect of narrative coherence on the extent to which low-level visual salience predicts eye gaze. Eye movements were recorded as 4-year-olds (n = 20) and adults (n = 20) watched a cohesive versus random sequence of video shots from a 4.5-min full vignette from Sesame Street. Overall, visual salience was a stronger predictor of gaze in adults than in children, especially when viewing a random shot sequence. The impact of narrative coherence on children's gaze was limited to the short period of time surrounding cuts to new video shots. The discussion considers potential direct effects of visual salience as well as incidental effects due to overlap between salient features and semantic content. The findings are also discussed in the context of developing video comprehension.

Age differences in orienting to faces in dynamic scenes depend on face centering, not visual saliency

The current study investigated how infants (6-24 months), children (2-12 years), and adults differ in how visual cues-visual saliency and centering-guide their attention to faces in videos. We report a secondary analysis of Kadooka and Franchak (2020), in which observers' eye movements were recorded during viewing of television clips containing a variety of faces. For every face on every video frame, we calculated its visual saliency (based on both static and dynamic image features) and calculated how close the face was to the center of the image. Results revealed that participants of every age looked more often at each face when it was more salient compared to less salient. In contrast, centering did not increase the likelihood that infants looked at a given face, but in later childhood and adulthood, centering became a stronger cue for face looking. A control analysis determined that the age-related change in centering was specific to face looking; participants of all ages were more likely to look at the center of the image, and this center bias did not change with age. The implications for using videos in educational and diagnostic contexts are discussed.

Effect of sequential video shot comprehensibility on attentional synchrony: A comparison of children and adults

To comprehend edited video, viewers must infer the meaning conveyed by successive video shots (i.e., continuous video segments separated by edit points, such as camera cuts). The central question here was whether comprehension-related top-down cognitive processes drive eye movements during sequential processing of video montage. Eye movements were recorded as 4 year olds and adults (n = 62) watched a video with the same constituent shots in either normal or random sequence. The key analyses compared eye movements to constituent shots when presented in normal order with those to the same shots presented in random order. The dependent variable was attentional synchrony or the extent to which viewers looked at the same location at the same time, indicating commonality of processing the video. This was calculated as the bivariate contour ellipse area within which points of gaze fell during each video frame. Results indicated that children were more scattered in their gaze locations than adults. Viewers became more similar to each other as normal vignettes unfolded over time; this was especially true in adults and possibly reflects a growing and shared understanding of the content. Conversely, adult attentional synchrony was reduced when watching random shot sequences. Thus, attentional synchrony during normal video viewing is driven not only by salient visual features, such as movement and areas of high contrast, but also, by the unfolding sequential comprehension of video montage, especially in adults. Differences between children and adults indicate that this top-down control of eye movements while watching video changes systematically over development.

Visual Attention Saccadic Models Learn to Emulate Gaze Patterns From Childhood to Adulthood

How people look at visual information reveals fundamental information about themselves, their interests and their state of mind. While previous visual attention models output static 2D saliency maps, saccadic models aim to predict not only where observers look at but also how they move their eyes to explore the scene. In this paper, we demonstrate that saccadic models are a flexible framework that can be tailored to emulate observer's viewing tendencies. More specifically, we use fixation data from 101 observers split into five age groups (adults, 8-10 y.o., 6-8 y.o., 4-6 y.o., and 2 y.o.) to train our saccadic model for different stages of the development of human visual system. We show that the joint distribution of saccade amplitude and orientation is a visual signature specific to each age group, and can be used to generate age-dependent scan paths. Our age-dependent saccadic model does not only output human-like, age-specific visual scan paths, but also significantly outperforms other state-of-the-art saliency models. We demonstrate that the computational modeling of visual attention, through the use of saccadic model, can be efficiently adapted to emulate the gaze behavior of a specific group of observers.