Tonal Symmetry Induces Fluency and Sense of Well-Formedness

Abstract

Fluency influences grammaticality judgments of visually presented strings in artificial grammar learning (AGL). Of many potential sources that engender fluency, symmetry is considered to be an important factor. However, symmetry may function differently for visual and auditory stimuli, which present computationally different problems. Thus, the current study aimed to examine whether objectively manipulating fluency by speeding up perception (i.e., manipulating the inter-stimulus interval, ISI, between each syllable of a string) influenced judgments of tonal strings; and thus how symmetry-based fluency might influence judgments. In Experiment 1, with only a test phase, participants were required to give their preference ratings of tonal strings as a measurement of fluency. In experiment 2, participants were instructed to make grammaticality judgments after being incidentally trained on tonal symmetry. Results of Experiment 1 showed that tonal strings with shorter ISI were liked more than those with longer ISI while such difference was not found between symmetric and asymmetric strings without training. Additionally, Experiment 2 found both main effects of symmetry and ISI as well as an interaction. In particular, only asymmetric strings were more likely to be judged as grammatical when they were presented at a shorter ISI. Taken together, participants were sensitive to the fluency induced by the manipulation of ISI and sensitive to symmetry only after training. In sum, we conclude that objective speed influenced grammaticality judgments, implicit learning of tonal symmetry resulted in enhanced fluency, and that fluency may serve as a basis for grammaticality judgments.

Keywords: AGL; fluency; grammaticality judgments; implicit learning; tonal symmetry.

FIGURE 1

An example of tonal symmetry. The symmetry relation employed by Jiang et al. (2012) and Ling et al. (2016; and in the present study) is based on the use of Chinese tones in Tang dynasty poetry, in which the tones of ping (i.e., tone 1 and tone 2) regularly correspond to the tones of ze (i.e., tone 3 and tone 4). The symmetry relation was constructed according to a mirror inversion of ping and ze tones with the first five tones predicting the last five ones. e.g., if the tone type of the first syllable was ping, then the tone type of the sixth syllable was ze, and so on.

FIGURE 2

The preference ratings of symmetric and asymmetric strings under different ISI conditions. The response of each individual as well as the average response was illustrated with standard error bars.

FIGURE 3

The endorsement rate of symmetric and asymmetric strings under different ISI conditions. The response of each individual as well as the average response was illustrated with standard error bars.