FIGURE 1.

Stimuli structure and examples. (A) Structure of the stimuli and the rule. Four-syllable sequences were constructed according to the artificial grammar rule A₁A₂B₂B₁, where A and B represent two classes of consonant-vowel syllables and indices 1 and 2 represent the pairing rule. The consonants, sharing the same place of articulation (pairs “b” – “p,” “g – k,” “d – t”), were paired by a center-embedding rule: The first consonant was paired with the last consonant, and the second consonant was paired with the third consonant. All sequences, following this rule, were correct. In incorrect sequences, the last consonant violates the pairing rule. (B) Examples of correct and incorrect stimuli.