The Neural Mechanisms of Private Speech in Second Language Learners’ Oral Production: An fNIRS Study
Abstract
:1. Introduction
1.1. Understanding Private Speech: Perspectives from Piaget and Vygotsky
1.2. The Role of Private Speech in Adults’ Second Language Learning
1.3. Neural Mechanisms of Private Speech: Insights from Inner and Outer Speech
1.4. The Current Study
2. Experiment 1: The Impact of Private Speech on L2 Oral Production
2.1. Objectives of Experiment 1
2.2. Materials and Methods
2.2.1. Participants
2.2.2. Materials
2.2.3. Task and Procedure
2.2.4. Data Coding
- “em and in the……it is the tree, the tree, grow up, the tree……faster than the boy……shorter, than the record before”.
- “等到了等到了春天还是夏天到了树叶再次茂盛的时候他们要站在这个树的下面像刚开始……似的……第一……的树然后发现钉子比他现在高了一截了” (When, when spring arrives, or summer arrives, the leaves grow lush again, they will stand beneath this tree, just like when they first……as the very first……tree, and then realize that the nail has risen a little higher than him).
2.3. Results
2.3.1. Preparation Phase: Private Speech
2.3.2. Execution Phase: Oral Production
2.4. Discussion
3. Experiment 2: Investigating the Neural Mechanisms of Private Speech in L2 Oral Production
3.1. Objectives of Experiment 2
3.2. Materials and Methods
3.2.1. Participants
3.2.2. Materials
3.2.3. Task and Procedure
3.2.4. Data Acquisition
3.2.5. Data Preprocessing
3.2.6. Data Analysis
3.3. Results
3.3.1. Activation Analysis
3.3.2. Functional Connectivity Analysis
3.4. Discussion
3.4.1. Activation of Different Speech Types
3.4.2. Private as a Thought-Regulation Tool Similar to Inner Speech
3.4.3. Private Speech as a Transitional Form Bridging Outer and Inner Speech
3.4.4. Summary and Pedagogical Implications
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
Abbreviations
L2 | Second language |
STG | Superior temporal gyrus |
IFG | Inferior frontal gyrus |
MTG | Middle temporal gyrus |
SMG | Supramarginal gyrus |
DLPFC | Dorsolateral prefrontal cortex |
fNIRS | Functional near-infrared spectroscopy |
U | Number of utterances |
W_PS | Number of words (during private speech) |
U/S | Average number of utterances per second |
W/U | Average number of words per utterance |
CAF | Complexity, accuracy, and fluency |
W_OP | Number of words (during oral production) |
AS | Analysis of speech |
W/AS | Average number of words per AS unit |
CAS | Complex analysis of speech |
EW | Number of erroneous words |
HbO | Oxygenated hemoglobin |
HbR | Deoxygenated hemoglobin |
tHb | Total hemoglobin |
FDR | False discovery rate |
CH | Channel |
OFC | Orbitofrontal cortex |
AG | Angular gyrus |
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Measures | High Proficiency | Low Proficiency |
---|---|---|
U | 99.750 (42.278) 1 | 106.500 (33.269) |
W_PS | 714.250 (371.590) | 671.125 (216.766) |
U/S | 0.166 (0.070) | 0.178 (0.055) |
W/U | 6.857 (1.800) | 6.424 (1.341) |
Measures | Inhibition | Private Speech Users | Non-Users of Private Speech | |||
---|---|---|---|---|---|---|
High | Low | High | Low | |||
Fluency | W_OP | Free | 311.313 (106.71) 1 | 300.000 (99.416) | 287.813 (62.778) | 283.563 (83.814) |
Inhibited | 282.000 (127.436) | 277.125 (100.601) | 294.313 (72.621) | 289.000 (112.140) | ||
AS | Free | 22.938 (8.790) | 27.813 (9.354) | 21.938 (5.196) | 23.375 (7.898) | |
Inhibited | 23.000 (9.913) | 27.000 (8.892) | 24.688 (7.245) | 24.688 (9.700) | ||
Complexity | CAS | Free | 7.500 (2.733) | 7.250 (5.209) | 7.625 (4.455) | 6.250 (3.088) |
Inhibited | 6.813 (3.563) | 5.625 (3.810) | 8.125 (3.364) | 7.375 (4.365) | ||
W/AS | Free | 14.024 (2.982) | 10.874 (1.258) | 13.357 (2.074) | 12.426 (1.930) | |
Inhibited | 14.021 (7.584) | 10.358 (1.546) | 12.225 (2.255) | 12.108 (3.106) | ||
Accuracy | EW | Free | 30.188 (19.181) | 29.125 (19.131) | 21.313 (12.700) | 30.250 (10.208) |
Inhibited | 27.250 (18.237) | 30.000 (23.232) | 20.375 (10.059) | 26.938 (11.066) |
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Jiang, R.; Xiao, Z.; Jiang, Y.; Jiang, X. The Neural Mechanisms of Private Speech in Second Language Learners’ Oral Production: An fNIRS Study. Brain Sci. 2025, 15, 451. https://doi.org/10.3390/brainsci15050451
Jiang R, Xiao Z, Jiang Y, Jiang X. The Neural Mechanisms of Private Speech in Second Language Learners’ Oral Production: An fNIRS Study. Brain Sciences. 2025; 15(5):451. https://doi.org/10.3390/brainsci15050451
Chicago/Turabian StyleJiang, Rong, Zhe Xiao, Yihan Jiang, and Xueqing Jiang. 2025. "The Neural Mechanisms of Private Speech in Second Language Learners’ Oral Production: An fNIRS Study" Brain Sciences 15, no. 5: 451. https://doi.org/10.3390/brainsci15050451
APA StyleJiang, R., Xiao, Z., Jiang, Y., & Jiang, X. (2025). The Neural Mechanisms of Private Speech in Second Language Learners’ Oral Production: An fNIRS Study. Brain Sciences, 15(5), 451. https://doi.org/10.3390/brainsci15050451