The Role of Phoneme in Mandarin Chinese Production: Evidence from ERPs

<div><p>Established linguistic theoretical frameworks propose that alphabetic language speakers use phonemes as phonological encoding units during speech production whereas Mandarin Chinese speakers use syllables. This framework was challenged by recent neural evidence of facilitation induced by overlapping initial phonemes, raising the possibility that phonemes also contribute to the phonological encoding process in Chinese. However, there is no evidence of non-initial phoneme involvement in Chinese phonological encoding among representative Chinese speakers, rendering the functional role of phonemes in spoken Chinese controversial. Here, we addressed this issue by systematically investigating the word-initial and non-initial phoneme repetition effect on the electrophysiological signal using a picture-naming priming task in which native Chinese speakers produced disyllabic word pairs. We found that overlapping phonemes in both the initial and non-initial position evoked more positive ERPs in the 180- to 300-ms interval, indicating position-invariant repetition facilitation effect during phonological encoding. Our findings thus revealed the fundamental role of phonemes as independent phonological encoding units in Mandarin Chinese.</p></div

Examples of experimental stimuli (A) and Experimental paradigm (B)

<p>. (A) For the phonologically related condition, the first (Experiment1) or the second (Experiment2) consonant in the Mandarin Chinese disyllabic names of prime picture and target picture were identical. For the phonologically unrelated condition, the corresponding manipulated phoneme was different. Numbers represent tone. (B) Each experimental trial was comprised of a naming procedure for the prime picture and then a naming procedure for the target picture.</p

Grand average ERPs at six ROIs in Experiment 1 (A) and Experiment 2 (B).

<p>The origin of the time-axis (0 ms) is placed at the onset of the target pictures. ERPs elicited in the phonologically related condition (solid line) were significantly more positive than the unrelated condition (dotted line) in the 180- to 300-ms interval after picture onset across six ROIs (light grey shading), indicating that overlap of either initial (Experiment 1) or non-initial phonemes (Experiment 2) facilitates early speech planning in Mandarin Chinese production. An inversion of the phonological repetition effect was found in the 350- to 450-ms time window in the mid-anterior region (dark grey shading), suggesting later self-monitoring inhibition.</p

Presentation of stimuli and dependent measures in Experiment 1.

Encoding time is measured as the gaze duration on the middle word. Decision time is the time from the onset of the last word until the indication of a response by a speeded key-press. A gaze-contingent display technique was used in which the words were masked except when the participant looked at them during the first reading pass from left to right. This eliminated preview and rereading of the first and middle word.</p

Grand average ERPs at six ROIs in Experiment 2 (400–700ms).

The origin of the time-axis (0ms) is placed at the onset of the target word, ERPs elicited in the large overall distance condition (dotted line) were significantly more positive than the small overall distance condition (solid line) in the 400- to 700-ms interval after third word onset across six ROIs (light grey shading).</p

Shape Representation of Word Was Automatically Activated in the Encoding Phase

<div><p>Theories of embodied language comprehension have proposed that language processing includes perception simulation and activation of sensorimotor representation. Previous studies have used a numerical priming paradigm to test the priming effect of semantic size, and the negative result showed that the sensorimotor representation has not been activated during the encoding phase. Considering that the size property is unstable, here we changed the target property to examine the priming effect of semantic shape using the same paradigm. The participants would see three different object names successively, and then they were asked to decide whether the shape of the second referent was more similar to the first one or the third one. In the eye-movement experiment, the encoding time showed a distance-priming effect, as the similarity of shapes between the first referent and the second referent increased, the encoding time of the second word gradually decreased. In the event-related potentials experiment, when the difference of shapes between the first referent and the second referent increased, the N400 amplitude became larger. These findiings suggested that the shape information of a word was activated during the encoding phase, providing supportive evidence for the embodied theory of language comprehension.</p></div

Dominance duration in Experiment 2 and 3.

A: Experiment 2 results. B: Experiment 3 results. Mm = male participants presented with male faces. Mf = male participants presented with female faces. Fm = female participants presented with male faces. Ff = female participants presented with female faces.</p

Topography of ERPs for the large overall distance and small overall distance condition (400–700ms).

<p>Topography of ERPs for the large overall distance and small overall distance condition (400–700ms).</p

Presentation of stimuli in Experiment 2.

<p>Stimuli were presented subsequently in the same position and sequence like Experiment 1, with time interval of 1000ms. The first word and second word would appear on the screen for 1000ms, the last word would kept seen until the participant has made a reaction. Between each trial, there was a blank screen of 500ms to 1000ms randomly.</p

Topography of ERPs for the low similarity and high similarity condition (400–500ms).

<p>Topography of ERPs for the low similarity and high similarity condition (400–500ms).</p