Gradient effects of within-category phonetic variation on lexical access

Area of Science:

• Psycholinguistics
• Speech Perception
• Phonetics

Background:

• Lexical access involves mapping spoken words to stored representations.
• The role of fine-grained acoustic-phonetic information in real-time word recognition is debated.
• Understanding how subtle speech sound variations influence perception is crucial for speech technology and language acquisition.

Purpose of the Study:

• To investigate whether small, within-category differences in voice onset time (VOT) influence lexical access.
• To determine if phonetic variations below the perceptual boundary affect word recognition processes.
• To examine the preservation of fine-grained acoustic differences in lexical activation patterns.

Main Methods:

• Eye movements of participants were monitored while they identified spoken words.
• Stimuli varied along a 0-40 ms voice onset time (VOT) continuum, including within-category variations.
• Participants viewed four pictures and selected the one named by the auditory stimulus.

Main Results:

• Within-category VOT differences led to gradient increases in fixations to cross-boundary lexical competitors.
• This effect intensified as the VOT approached the phonetic category boundary.
• Eye movement patterns indicated that subtle acoustic-phonetic distinctions are maintained during lexical processing.

Conclusions:

• Fine-grained acoustic-phonetic differences, specifically in VOT, are preserved in lexical activation.
• These subtle differences influence the activation of competing lexical candidates.
• Such phonetic detail can enhance the efficiency of on-line word recognition.