Continuous dynamics in behavior reveal interactions between perceptual warping in categorization and speech-in-noise...

Area of Science:

• Psycholinguistics
• Auditory Perception
• Speech Processing

Background:

• Spoken language comprehension involves mapping continuous speech signals to discrete categories.
• Perceptual categories are dynamic, shifting based on context and stimulus order (perceptual warping).
• The influence of perceptual warping on speech processing in noisy environments is not well understood.

Purpose of the Study:

• To investigate if perceptual warping affects speech processing in noise-degraded listening scenarios.
• To examine how stimulus order influences phonetic category judgments in clean and noisy conditions.

Main Methods:

• Mouse tracking was used to measure continuous perception and category judgments of an acoustic-phonetic vowel gradient.
• Listeners categorized vowel continua presented in either serial (inducing more warping) or random orders.
• Experiments were conducted in both clean and noise-degraded listening conditions.

Main Results:

• Listeners showed faster responses and more direct mouse trajectories towards category exemplars in serial compared to random orders, indicating increased perceptual attraction.
• These order effects were more pronounced and persisted longer in the trial time course during noise-degraded conditions.
• Perceptual warping strengthened behavioral attraction to speech categories, leading to more decisive judgments.

Conclusions:

• Perceptual warping enhances categorical perception and strengthens behavioral attraction to relevant speech categories.
• This phenomenon impacts speech-in-noise perception, making listeners more decisive in their categorizations.
• While warping increases decisiveness, it does not necessarily improve accuracy in speech perception tasks.