A round Bouba is easier to remember than a curved Kiki: Sound-symbolism can support associative memory

Past research has shown that prior knowledge can support our episodic memory for recently encountered associations. According to the model proposed by Cox and Criss (Proceedings of the 40th Annual Conference of the Cognitive Science Society, pp. 250-255, Madison, MI: Cognitive Science Society, 2018) and Cox and Shiffrin (Cognitive Psychology, 97, 31-61, 2017), any features shared by associated items should facilitate encoding and retrieval. We implemented a strict test of this prediction by taking advantage of sound-symbolism associations; here, the latter refer to relationships between phonemes and object characteristics - relationships that participants readily find natural - even if they have never encountered the items before. For instance, the non-word "maluma" is much more readily seen to refer to a random shape with rounded contours than to a shape that has sharp angles. In our study, 70 participants completed paired-associate memory tests after studying lists of three pairs, each composed of a random shape and a non-word. As predicted, there was better associative memory performance for sound-shape pairs that could rely on sound-symbolism links.