Size Sound Symbolism Modulates Linguistic Processing: An ERP Study

The size of physical objects is systematically associated with specific speech sounds used to refer to these objects. This phenomenon, termed size sound symbolism, has been demonstrated with a number of different behavioral measures such as word rating or word selection tasks. Yet, there is little data on where and how such sound-symbolic associations come into play within the brain's cognitive processing hierarchy. In the present EEG study, we investigated whether the neural activation of associations based on size sound symbolism can be automatic by nature. Participants were presented with small or large novel visual objects (greebles), followed by small-sounding or large-sounding (containing the letter <i> or <a>) fictional greeble names. We found, in accordance with our hypotheses, that the processing of sound-symbolically congruent names, compared to incongruent names, elicited a reduced N400 ERP component, in particular with regard to the small greebles. An additional exploratory analysis revealed an effect of size sound symbolism also in a subsequent time window, capturing a late positive component. These findings were evident in the absence of any task demands or conscious awareness related to sound symbolism. We argue that the greebles' presentation entailed an automatic activation of sound-symbolically associated linguistic information, which in turn facilitated the subsequent linguistic processing of sound-symbolically matching input, followed by stronger engagement of memory functions. The present study thus demonstrates that size sound symbolism is an inherent component of the brain's information processing system rather than a product of deliberate decision or response mechanisms and that it thereby exerts a significant influence on how we experience the world around us.