Predictability affects early perceptual processing of word onsets in continuous speech.

Area of Science:

• Cognitive Neuroscience
• Psycholinguistics
• Auditory Perception

Background:

• Event-related potentials (ERPs) suggest listeners selectively attend to word onsets in continuous speech.
• The underlying reasons for this preferential processing of word onsets remain unclear.
• Understanding attentional mechanisms in speech processing is crucial for fields like audiology and artificial intelligence.

Purpose of the Study:

• To investigate the hypothesis that listeners attend to word onsets due to their unpredictability.
• To examine how predictability influences attentional allocation in continuous speech.
• To explore the neural correlates of attentional selection in artificial language perception.

Main Methods:

• Measurement of event-related potentials (ERPs) elicited by syllable onsets.
• Use of an artificial language with a continuous speech stream of nonsense words.
• Manipulation of word predictability by arranging words in predictable pairs before and after recognition training.

Main Results:

• A larger negativity, indicative of selective attention, was observed around 100 ms after the onset of the first word in a pair after training.
• This attentional effect was significantly reduced or absent for the completely predictable second word in each pair.
• The findings demonstrate a clear link between predictability and the allocation of attention to speech segments.

Conclusions:

• Listeners direct their attention to speech segments that are least predictable.
• Unpredictability, rather than simply word onset, appears to be the primary driver of selective attention in continuous speech.
• This research offers new insights into the dynamic attentional processes involved in real-time speech comprehension.