ИСТИНА

Frequency of a word tends to determine its processing time in a lexical decision task. Apart from surface and lemma frequencies, more subtle measures such as entropies of inflectional and derivational paradigms elaborated within the informational approach in psycholinguistics are assumed to be good predictors for response latencies (see, e.g., Baayen et al., 2006; Milin et al., 2009). Yet, as far as noun case processing is concerned, evidence supporting effects of entropy measures comes most exclusively from Serbian. That is why for our study we chose Russian as the target language, also being Slavic with a declension system similar to Serbian’s. We selected 54 female and 54 male base nouns belonging to the 1a inflectional class according to Zalizniak (1977) in order to avoid possible influence of additional factors such as stress, regularity and derivation. Lemma and surface frequency counts were obtained manually from National Russian Corpus (www.ruscorpora.ru), frequency of exponents was taken from the database by Slioussar & Samojlova (2014). In our lexical decision experiment words are presented in all case forms in singular number. Nouns with pseudoendings and inflected pseudostems serve as nonwords. Latin square design is employed with the number of lists corresponding to the number of caseforms. The experiment currently being in progress, we plan to present the results at the workshop. We will discuss the impact of inflectional entropy on reaction times, its possible interaction with gender and present the implications for existing theories of morphological processing.