The subconscious impact of line orientations in background images on memory of Chinese written characters.

Oriented lines impact human cognition subconsciously. This study aimed to determine whether line orientations in the background of Chinese written characters influenced individual's memory and emotion. Five pictures with Chinese characters as experimental material, in which four had equidistant parallel lines (0°, -45°, 90°, and +45°) as background and the other one had a blank background, were presented on a personal computer screen, for 15 seconds each, to 94 participants. The participants were then given 45 seconds to write down what they had just memorized. Participants' emotion was identified by their Heart Rate Variability (HRV) simultaneously during the viewing process. The results showed that vertical (90°) and 45° leftward leaning lines (-45°) did not weaken users' memory, and no significant difference in memory was found between these two states and the blank background, while horizontal (0°) and 45° rightward leaning lines (+45°) weakened the memory effect significantly. Overall, memory decreased in the condition of horizontally lined background while no influence in vertically lined background condition; and it showed asymmetry under leftward and rightward leaning line conditions: memory decreased in rightward leaning lined background while no influence in leftward lined background. Moreover, the results of emotion and memory showed negative similar trend. These findings provide practical suggestions for visual information design.