For L2 and mental imagery, though studies are limited, Kühne and Gianelli (2019) suggest that L1 is connected and reinforced through perception and physical action from an early age and thus has more vivid and emotional connections, whereas L2 is often taught through textbooks, memorization, and symbol manipulation in classroom settings. This relationship is similar to the theory presented by Hayakawa and Keysar (2018) that forming mental imagery is related to abilities to retrieve episodic memories. The retrieval of memory is also dependent on the language they used to encode. The authors conclude that as most episodic memories are encoded in L1, they will be less accessible in L2, resulting in difficulty producing mental imagery in L2.