Lexical effects in phonemic processing: facilitatory or inhibitory

Area of Science:

• Psycholinguistics
• Cognitive Science
• Speech Perception

Background:

• Understanding how listeners identify spoken words is crucial in psycholinguistics.
• Models of speech perception differ on the role and timing of lexical information.
• Autonomous models suggest lexical access occurs after phoneme processing, while interactive models propose parallel processing.

Purpose of the Study:

• To investigate the temporal dynamics of lexical effects on phoneme identification.
• To differentiate between predictions of autonomous and interactive models of speech perception.
• To determine the conditions under which lexical information influences phoneme monitoring.

Main Methods:

• Phoneme-monitoring experiments were conducted.
• Participants detected phoneme targets in words and matched nonwords.
• Latency differences were analyzed to assess lexical facilitation and inhibition.

Main Results:

• Significant lexical facilitation was observed only when phoneme targets appeared after the word's uniqueness point.
• No evidence for lexically mediated inhibition of phoneme identification was found.
• Results contradicted predictions of the interactive activation model TRACE.

Conclusions:

• Lexical information exerts a limited influence on phoneme identification, primarily occurring late in word processing.
• The findings support constraints on the interaction between lexical knowledge and early speech perception.
• Speech perception is not fully driven by lexical information, especially for unambiguous speech signals.