Fig. 1.

Design of the study. (A) illustrates the pre- and post-test scenario, in which all pseudowords (n = 36) were presented twice in a randomized order (stimulus onset asynchrony of 8 s (mean) with a jitter of 6–10 s). The video on the screen was shown to keep infants attention. (B) During training, performed between pre- and post-test on each day, half of the legal (n = 9) and half of the illegal (n = 9) pseudowords were presented with the pseudoobjects (tight temporal co-occurrence; attention grabber to alert the infant). (C) To establish an associative link during training a given pseudoword was presented 6 times with a specific pseudoobject and 6 times with variable other objects. (D) The analysis was performed for EEG and fNIRS data only during pre- and post-tests. Four factors were analyzed: short term effect of training immediately prior to and after training (PREPOST) and the long term effect over the three consecutive days (DAY); the factor TRAIN differentiates between trained/untrained pseudowords (train/untr) while the factor LEGALITY (not illustrated) differentiates phonotactically legal from illegal pseudowords.