Connections are not enough for membership: Letter/non-letter distinction persists through phonological association learning.

In compound, hierarchical stimuli (also known as Navon figures), a Global Precedence Effect (GPE) can reliably be observed for both letters and non-letters. However, when presentation conditions sufficiently resemble those of reading, the GPE for letters has occasionally been found to disappear. We corroborate this effect in a study with a large group of participants. In addition, in-between two sessions, participants were trained in associating the non-letters with either phonological or non-phonological sounds. We reasoned that learning distinctive phonological associations might be akin to the acquisition of letter knowledge. This might eliminate the GPE also for the non-letters. However, the GPE persisted for the trained non-letters in both conditions. The large number of participants in this study revealed additional effects in the letter condition, which enabled further insights in the processing dissociation between letters and non-letter shapes.