Pre-Conscious Automaticity of Sound-­‐Shape Mapping

Abstract

The bouba–kiki effect depicts a non-arbitrary mapping between specific shapes and non-words: an angular shape is more often named with a sharp sound like ‘kiki’, while a curved shape is more often matched to a blunter sound like ‘bouba’. This effect shows a natural tendency of sound-shape pairing and has been shown to take place among adults who have different mother tongues (Ramachandran & Hubbard, 2001), pre-schoolers (Maurer, Pathman, & Mondloch, 2006), and even four-month-olds (Ozturk, Krehm, & Vouloumanos, 2013). These studies therefore establish that similar sound-to-shape mappings could happen among different cultures and early in development, suggesting the mappings may be innate and possibly universal. However, it remains unclear what level of mental processing gives rise to these perceptions: the mappings could rely on introspective processes about ‘goodness-of-fit,’ or they could rely on automatic sensory processes which are active prior to conscious awareness. Here we designed several experiments to directly examine the automaticity of the bouba-kiki effect. Specifically, we examined whether the congruency of a sound-shape pair can be processed before access to awareness?