Novitskiy, N. 1 , Myachikov, A. 1, 2 & Shtyrov, Y. 1, 3
1 Center for Cognition and Decision Making, Higher School of Economics, Russia
2 Department of Psychology, Northumbria University, Newcastle upon Tyne, UK
3 Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark
We investigated crosslinguistic phonological and semantic similarity effects on the activation of bilingual lexicon in the human brain. Russian-English late unbalanced bilinguals were tested in a masked priming paradigm with L1 (Russian) words as masked primes and L2 (English) words as targets. The experimental task was to maintain the targets in memory until the next trial and match them against occasionally presented catch stimuli. In different randomly presented pairs, the primes and the targets either overlapped (1) phonetically, (2) semantically, (3) both phonetically and semantically, or (4) did not overlap. In parallel, we continuously recorded 128-channel electroencephalogram (EEG) and measured the event-related potentials amplitude at N170 and N400 latencies. Phonological similarity between primes and targets reduced the task performance for both semantically related and unrelated pairs and reduced the amplitude of N400 in the semantically unrelated condition. This interaction between semantics and phonology was underpinned by activity in the left inferior temporal gyrus in the EEG source reconstruction. In conclusion, phonological decoding of prime-target pairs interacted with their semantic decoding. Phonetically similar words in the two languages shared short-term memory representations that caused ambiguity during the recall of the written form as well as reduced performance that accompanied this ambiguity.