Visual Effect of “Speed Lines” in Manga

An Experimental Study on Spatial Attention

Abstract

Manga is a visual art consisting of still images, words, and various symbolic rep-
resentations. “Speed lines” are type of the symbolic representation in manga. They
are typically depicted as several lines placed on the opposite side of the direction of
motion. Although readers of manga can empirically estimate the motion direction of
objects with speed lines, few studies have experimentally examined the perception of
speed lines. We hence investigated spatial attention arising from speed lines by using a
pre-cuing technique (Posner, 1980). For example, if speed lines placed on the left side of
a depicted object induced a rightward motion perception, then spatial attention to the
right should be enhanced. A total of thirty university students who have read manga
before participated in two experiments. In Experiment 1, we employed schematic balls
with or without speed lines as cues and measured reaction times for three different
conditions. Target stimuli were presented on the opposite or the same side of the speed
lines across the balls in the congruent and incongruent conditions, respectively. In the
neutral condition, the schematic balls without speed lines were used as cues. Reaction times were found to be shorter for the congruent condition than the incongruent
and neutral conditions. In Experiment 2, schematic balls with four figures instead of speed
lines were used as cues in order to elucidate the particularity of the speed lines. Reac-
tion times were shorter for the congruent and incongruent conditions than the neutral con-
dition, and did not differ significantly between the congruent and incongruent conditions. These results indicated that spatial attention toward the direction of motion
corresponding to manga artists’ intention was aroused by speed lines. Therefore, we
conclude that adults who read manga can perceive the motion direction of objects with
speed lines.