Motion impressions enhanced by converging motion lines

Are We Moving Too Fast?: Representation of Speed in Static Images

Despite pictures being static representations, they use various cues to suggest dynamic motion. To investigate the effectiveness of different motion cues in conveying speed in static images, we conducted 3 experiments. In Experiment 1, we compared subjective speed ratings given for motion lines trailing behind movers, suppletion lines replacing parts of the movers and backfixing lines set in the background against the baseline of having no extra cue. Experiment 2 was a replication of the first experiment with an addition of several motion lines considering the effect of quantity on conveyed speed. Experiment 3 then examined the actual time assessments of each cue and bare objects indicated for movers to complete their paths. Our results showed that motion cues vary in their effectiveness in depicting speed, with some influence from proficiency in reading manga. Motion lines, which index the path being traversed, remained less effective than suppletion and backfixing lines, which we argue encode the speed component of motion rather than directionality. However, adding more motion lines intensified the perceived speed of the movers. These static cues also influenced the actual time durations individuals indicated for fictitious motion events, in line with the subjective speed ratings. Altogether, our results suggest that different aspects of motion can be captured by different cues, and that the effectiveness of cues might be modulated by exposure to such patterns, in line with the premises of a visual lexicon view.

The role of texture summary statistics in material recognition from drawings and photographs

Material depictions in artwork are useful tools for revealing image features that support material categorization. For example, artistic recipes for drawing specific materials make explicit the critical information leading to recognizable material properties (Di Cicco, Wjintjes, & Pont, 2020) and investigating the recognizability of material renderings as a function of their visual features supports conclusions about the vocabulary of material perception. Here, we examined how the recognition of materials from photographs and drawings was affected by the application of the Portilla-Simoncelli texture synthesis model. This manipulation allowed us to examine how categorization may be affected differently across materials and image formats when only summary statistic information about appearance was retained. Further, we compared human performance to the categorization accuracy obtained from a pretrained deep convolutional neural network to determine if observers' performance was reflected in the network. Although we found some similarities between human and network performance for photographic images, the results obtained from drawings differed substantially. Our results demonstrate that texture statistics play a variable role in material categorization across rendering formats and material categories and that the human perception of material drawings is not effectively captured by deep convolutional neural networks trained for object recognition.

The Meaning of Motion Lines?: A Review of Theoretical and Empirical Research on Static Depiction of Motion

Static depiction of motion, particularly lines trailing behind a mover, has long been of interest in the psychology literature. Empirical research has demonstrated that these "motion lines" benefited motion comprehension in static images by disambiguating the direction of movement. Yet, there is no consensus on how those lines derive their meaning. In this article, we review three accounts suggesting different interpretations of what motion lines represent. While a perceptual account considers motion lines originating from motion streaks in the primary visual cortex, metaphorical and lexical accounts propose them as graphical conventions that should be learned-either through resemblance to sensory experiences (e.g., natural path marks) or directly being mapped to a conceptual category of paths. To contrast these three accounts, we integrate empirical research on motion lines and their understanding. Overall, developmental, proficiency, and cross-cultural variances indicate that the understanding of motion lines is neither innate nor universal, thus providing less support for lines having a purely perceptual origin. Rather, we argue the empirical findings suggest that motion lines are not iconic depictions of visual percepts but are graphical conventions indexing conceptual path information, which need to be learned and encoded in a visual lexicon.

The framing of subjectivity: Point-of-view in a cross-cultural analysis of comics

In visual narratives like comics, the most overt form of perspective-taking comes in panels that directly depict the viewpoints of characters in the scene. We therefore examined these subjective viewpoint panels (also known as point-of-view panels) in a corpus of over 300 annotated comics from Asia, Europe, and the United States. In line with predictions that Japanese manga use a more 'subjective' storytelling style than other comics, we found that more manga use subjective panels than other comics, with high proportions of subjective panels also found in Chinese, French, and American comics. In addition, panels with more 'focal' framing, i.e. micro panels showing close ups and/or amorphic panels showing views of the environment, had higher proportions of subjective panels than panels showing wider views of scenes. These findings further show that empirical corpus analyses provide evidence of cross-cultural variation and reveal relationships across structures in the visual languages of comics.

Linguistic typology of motion events in visual narratives

Languages use different strategies to encode motion. Some use particles or "satellites" to describe a path of motion (Satellite-framed or S-languages like English), while others typically use the main verb to convey the path information (Verb-framed or V-languages like French). We here ask: might this linguistic variation lead to differences in the way paths are depicted in visual narratives like comics? We analyzed a corpus of 85 comics originally created by speakers of S-languages (comics from the United States, China, Germany) and V-languages (France, Japan, Korea) for both their depictions of path segments (source, route, and goal) and the visual cues signaling these paths and manner information (e.g., motion lines and postures). Panels from S-languages depicted more path segments overall, especially routes, than those from V-languages, but panels from V-languages more often isolated path segments into their own panels. Additionally, comics from S-languages depicted more motion cues than those from V-languages, and this linguistic typology also interacted with panel framing. Despite these differences across typological groups, analysis of individual countries' comics showed more nuanced variation than a simple S-V dichotomy. These findings suggest a possible influence of spoken language structure on depicting motion events in visual narratives and their sequencing.

The notion of the motion: the neurocognition of motion lines in visual narratives

Motion lines appear ubiquitously in graphic representation to depict the path of a moving object, most popularly in comics. Some researchers have argued that these graphic signs directly tie to the "streaks" appearing in the visual system when a viewer tracks an object (Burr, 2000), despite the fact that previous studies have been limited to offline measurements. Here, we directly examine the cognition of motion lines by comparing images in comic strips that depicted normal motion lines with those that either had no lines or anomalous, reversed lines. In Experiment 1, shorter viewing times appeared to images with normal lines than those with no lines, which were shorter than those with anomalous lines. In Experiment 2, measurements of event-related potentials (ERPs) showed that, compared to normal lines, panels with no lines elicited a posterior positivity that was distinct from the frontal positivity evoked by anomalous lines. These results suggested that motion lines aid in the comprehension of depicted events. LORETA source localization implicated greater activation of visual and language areas when understanding was made more difficult by anomalous lines. Furthermore, in both experiments, participants' experience reading comics modulated these effects, suggesting motion lines are not tied to aspects of the visual system, but rather are conventionalized parts of the "vocabulary" of the visual language of comics.

The Effect of Motion Lines on Apparent-Motion Correspondence under Dichoptic Presentation

Motion lines enhance the impression of motion when viewing static/dynamic images. I investigated the binocularity of the motion-enhancing effect in an ambiguous apparent-motion display. Even in the dichoptic presentation condition, the effect of motion lines on apparent-motion correspondence was as strong as that in the monoptic condition. Additionally, there were no effects of stereo-depth separation. These results suggest that the effect of motion lines arises from a higher-level motion-processing mechanism that occurs after integrating information from both eyes.

Ventral and dorsal streams processing visual motion perception (FDG-PET study)

BACKGROUND

Earlier functional imaging studies on visually induced self-motion perception (vection) disclosed a bilateral network of activations within primary and secondary visual cortex areas which was combined with signal decreases, i.e., deactivations, in multisensory vestibular cortex areas. This finding led to the concept of a reciprocal inhibitory interaction between the visual and vestibular systems. In order to define areas involved in special aspects of self-motion perception such as intensity and duration of the perceived circular vection (CV) or the amount of head tilt, correlation analyses of the regional cerebral glucose metabolism, rCGM (measured by fluorodeoxyglucose positron-emission tomography, FDG-PET) and these perceptual covariates were performed in 14 healthy volunteers. For analyses of the visual-vestibular interaction, the CV data were compared to a random dot motion stimulation condition (not inducing vection) and a control group at rest (no stimulation at all).

RESULTS

Group subtraction analyses showed that the visual-vestibular interaction was modified during CV, i.e., the activations within the cerebellar vermis and parieto-occipital areas were enhanced. The correlation analysis between the rCGM and the intensity of visually induced vection, experienced as body tilt, showed a relationship for areas of the multisensory vestibular cortical network (inferior parietal lobule bilaterally, anterior cingulate gyrus), the medial parieto-occipital cortex, the frontal eye fields and the cerebellar vermis. The "earlier" multisensory vestibular areas like the parieto-insular vestibular cortex and the superior temporal gyrus did not appear in the latter analysis. The duration of perceived vection after stimulus stop was positively correlated with rCGM in medial temporal lobe areas bilaterally, which included the (para-)hippocampus, known to be involved in various aspects of memory processing. The amount of head tilt was found to be positively correlated with the rCGM of bilateral basal ganglia regions responsible for the control of motor function of the head.

CONCLUSIONS

Our data gave further insights into subfunctions within the complex cortical network involved in the processing of visual-vestibular interaction during CV. Specific areas of this cortical network could be attributed to the ventral stream ("what" pathway) responsible for the duration after stimulus stop and to the dorsal stream ("where/how" pathway) responsible for intensity aspects.

Vection can be induced in the absence of explicit motion stimuli

The present study utilized two separate experiments to demonstrate that illusory self-motion (vection) can be induced/modulated by cognition. In the first experiment, two curved lines, which simulated road edges seen while driving at night, were employed. Although the lines induced adequate strength of forward vection, when one of the lines was horizontally reversed, vection was significantly reduced. In the second experiment, two static converging lines with moving characters, which simulated side edges of a straight road with a traffic sign, were utilized. The road sign moved only during the first 5 s. After the sign disappeared, only static lines or a blank screen were able to induce vection. These results suggested that vection was largely affected by cognitive factors and that vection could be induced by implicit motion stimuli.