Targeting the neural bases of novel word acquisition using theta-band transcranial alternating current stimulation

Novel word acquisition is crucial for both first language acquisition and foreign language learning. Most previous studies of its neural bases were conducted via neuroimaging methods, which can reveal correlational but not causal links between neural and cognitive processes. This paper is one of the first to study the effect of transcranial alternating current stimulation on novel word acquisition. We developed a new explicit word learning paradigm with 80 pseudowords paired with 80 Russian nouns. Online validation revealed no floor or ceiling effects, so the paradigm provides optimal difficulty for potentially modulating performance with tACS. We applied theta-band (5.5 Hz) anti-phase tACS over the left frontal-temporal regions in 30 healthy young participants using the paradigm. TACS did not significantly modulate any performance measures and further research is required to test its spatial, frequency, and phase-specific effects.