Comprehending action in depicted paths: Evidence from the cognition of motion lines in visual narratives

Comprehending action in depicted paths: Evidence from the cognition of motion lines in visual narratives Neil Cohn (neilcohn@visuallanguagelab.com) Center for Research in Language, University of California, 9500 Gilman Dr. Dept. 0526, San Diego, La Jolla, CA 92093-0526 Stephen Maher (smaher@mclean.harvard.edu) Mclean Hospital, Harvard Medical School, Belmont, MA 02478 Abstract 1990). Second, people of cultures unfamiliar with this style of drawing have trouble understanding that these lines depict motion, though they do understand accompanying iconic representations (Kennedy & Ross, 1975; Winter, 1963). Third, interpretation of motion lines appears to change as people age (Carello, Rosenblum, & Grosofsky, 1986; Friedman & Stevenson, 1975; Gross et al., 1991). Younger children interpret motion lines as invisible yet iconic physical forces, such as wind, but recognize them as symbolic conventions as they grow older (Gross et al., 1991). Fourth, the representations of motion lines vary cross-culturally in comics and other drawing systems (Cohn, 2013; McCloud, 1993). Fifth, motion lines appearing in comics use a wide range of shapes, not only trailing laterally moving objects, including bouncing or spinning (Cohn, 2013; McCloud, 1993). Altogether, these findings suggest that motion lines do not originate in vision, but rather come from being a conventionalized graphic representation. Nevertheless, research has mostly explored how motion lines graphically depict events and motion. In general, images with motion lines are thought to depict more motion than those with only postural cues (Brooks, 1977; Friedman & Stevenson, 1975; Gross et al., 1991; Ito, Seno, & Yamanaka, 2010; Kawabe & Miura, 2006). Also, more lines and longer lines lead to participants interpreting faster movement (Hayashi, Matsuda, Tamamiya, & Hiraki, 2012). Furthermore, motion lines that trail an object have been rated as more effective at depicting motion than a lack of lines, background lines, or lines moving in the wrong direction (Ito et al., 2010). One reason that motion lines facilitate comprehension and memory of depicted events more than when those same images lack motion lines is because they help clarify the interaction between entities that otherwise may remain underspecified (Brooks, 1977). Despite the wealth of research investigating motion lines, especially with seriousness for their supposed implications on motion understanding, most of these studies remain limited. Even though motion lines appear ubiquitously in comics—and most studies emphasize this fact—few studies make use of this context and therefore do not reflect the full range of complexity and richness that goes into their comprehension. For example, stimuli typically use abstract circles or squares with a trailing motion line, focus specifically on the action of running, and/or only use straight lateral motions. However, in comics, motion lines Motion lines depict the path of a moving object, most popularly in comics. Some have argued that motion lines depict the “streaks” in the visual system when a viewer tracks an object (Burr, 2000). However, previous research has not used motion lines’ natural context of comics, has only depicted a limited number of actions (usually just running), and used only offline measurements like recall or ratings. Here, we compared panels in comic strips with normal motion lines and those depicting either no lines or reversed, anomalous lines. In Experiment 1, images with normal lines were faster than no lines, which were viewed faster than anomalous lines. In Experiment 2, ERPs showed that the absence of normal lines elicited a posterior positivity distinct from the frontal positivity evoked by the presence of anomalous lines. These results suggest that motion lines aid in the comprehension of depicted events as conventionalized visual signs. Keywords: Motion lines; comics; visual language; events; motion; event-related potential; P600; P300. Introduction The depiction of motion poses a challenge for static images. Motion lines (also called action or speed lines) offer a solution to this issue by depicting the path of an action by attaching a line or series of lines to a moving object. These representations are especially pervasive in the visual vocabulary used in comics across the world (Cohn, 2013; McCloud, 1993). Despite their origins in comics and drawings, researchers have claimed that the comprehension of motion lines originates in the biological foundations of vision. Since moving objects leave behind “streaks” in the visual system when a viewer tracks an object (Geisler, 1999), similar to a slow shutter speed of a camera, they argue that this residual could form the basis of our understanding about motion lines (Burr, 2000). Subsequent research has stressed that participants better understand or remember the direction of moving objects when they have motion lines than when they do not (Kawabe & Miura, 2006; Kim & Francis, 1998). Thus, under this interpretation, motion lines are a depiction of a basic aspect of human perception rooted directly in the visual system. Nevertheless, this view has several limitations. First, motion lines are understood by blind people comparably to sighted people when presented using pictures with raised- lines similar to braille (Kennedy, Gabias, & Piertantoni,