Lexical access allows the immediate understanding and production of words online. Despite being a basic linguistic computation, there is a lot of heated theoretical dispute in this area. This study will present an empirical research whose results shed light on the way we access transparent and semantically opaque words (as whole words vs. by affix stripping) and on the method of storing them in the mind (morphologic vs. semantic routes).
The Distributed Morphology theory suggests there are different lexical approaches, originated from psychologically different processes. However, we are interested in the access of words that bear a morphological relationship between them and that once also shared a semantic relation, but that under the synchronous perspective have lost it. For instance, liquidação (Brazilian Portuguese for the word sale) derives diachronically from líquido (liquid), but nowadays Brazilian speakers seem to ignore this semantic relationship. This very specific type of morphologic and semantic relationship between words has never been tested before in this language.
In order to evaluate MD predictions, we ran a priming test with a lexical decision judgment (word/non-word). We compared pairs of synchronically semantically unrelated (but morphologically linked) words -like líquido/liquidação (liquid/sale)- with pairs that maintain a transparent compositional relationship -like líquido/liquidificar (liquid/liquefy)- and with pairs that maintain only a semantic (and not morphological) relationship -like líquido/aquoso (liquid/aqueous). For each of these three conditions, we selected stimuli with two different sizes/morphologic layers: for instance, “líquido-liquidação”(liquid-sale) pairs, presented above, stand for the long condition of the opaque relationship, while “líquido-liquidar”(liquid-liquidate) pairs stand for the short one.
The results of a first behavioral pilot test confirmed the MD hypothesis, evidencing i) a decompositional course during processing, regardless of semantic opacity; ii) new entries for words such as liquidação (sale) in the mental lexicon; and iii) different psychological processes for the morphologic and semantic routes: we propose linguistic composition for the former and joint memory for the latter.
Our next step will be to run an EEG test with the same design. We expect to find wider ERP amplitudes for the semantically opaque conditions and different latencies between two-different-size stimuli (2 and 3 morphologic layers) for both the transparent and opaque morphological conditions, but not for the semantic-only one. These findings would confirm our previous conclusions for the pilot test.