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Updated: May 23, 2026
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Interaction between Phonological and Semantic Processes in Visual Word Recognition using Electrophysiology
Published on: June 29, 2021
Neural Sensitivity to Word Frequency Modulated by Morphological Structure: Univariate and Multivariate fMRI Evidence
Joonwoo Kim1, Solbin Lee1, Kichun Nam1
1Korea University.
Journal of Cognitive Neuroscience
|May 21, 2026
Summary
Visual word recognition relies on whole-word access, not obligatory decomposition, especially for frequent inflected words. Lexical statistics, particularly whole-word frequency, shape neural responses in language processing areas.
Area of Science:
- Psycholinguistics
- Neuroscience
- Computational Linguistics
Background:
- The debate in visual word recognition centers on whether morphologically complex words are always broken down (decomposed) or if familiar whole words can be accessed directly.
- Korean nominal inflection offers a unique opportunity to study this by separating base (stem) frequency from surface (whole-word) frequency.
Purpose of the Study:
- To investigate how morphological complexity and lexical frequency interact to influence neural responses during visual word recognition.
- To test whether visual word recognition involves obligatory decomposition or allows for whole-word access based on word frequency.
Main Methods:
- A rapid event-related functional Magnetic Resonance Imaging (fMRI) lexical decision task was conducted with 25 native Korean speakers.
- Participants decided if presented stimuli were real words, with stimuli varying in morphological complexity and base/surface frequency.
- Representational Similarity Analysis (RSA) and univariate analyses were used to examine brain activity in response to word properties.
Main Results:
- Representational Similarity Analysis revealed that surface word frequency, not base word frequency, was robustly encoded in the inferior frontal gyrus pars opercularis and supramarginal gyrus.
- These correlations were stronger for inflected words than simple nouns.
- Univariate analyses showed surface frequency specifically increased activation in inferior parietal regions for inflected nouns, while base frequency had no significant effects.
Conclusions:
- Findings challenge models that assume obligatory prelexical decomposition of complex words.
- Results support models where morphological processing is influenced by postlexical, usage-based lexical statistics (e.g., whole-word frequency).
- Morphological processing appears to be a distributed process influenced by both word structure and statistical learning from language use.
