Sensorimotor Adaptation to a Nonuniform Formant Perturbation Is Preserved in Healthy Aging.

Speakers adapted to the centralization perturbation by producing trained corner vowels farther from the vowel center with increased acoustic contrast.

• Forty-three neurobiologically healthy speakers participated, with an age range of 18–73 years.
• Speakers read monosyllabic words with corner vowels while auditory feedback was shifted toward the center of the vowel space.
• Adaptation was measured as the increase in vowel contrast induced by this perturbation.
• The result replicates prior findings that nonuniform centralization perturbations induce speakers to increase vowel-to-vowel acoustic contrast.

Sensorimotor adaptation generalized robustly to untrained noncorner vowels.

• Generalization was tested using monosyllabic words with noncorner vowels produced under masking noise.
• The generalization of learning to untrained vowels was described as 'robust.'
• This indicates that the adaptation was not limited to the specific trained corner vowels but extended across the vowel space.

Age did not affect the magnitude of adaptation to the centralization perturbation.

• The sample spanned a wide age range of 18–73 years, allowing examination of continuous age effects.
• Age did not significantly predict the degree of sensorimotor adaptation to the perturbation.
• This finding held despite established age-related deficits in speech motor performance noted in the literature.

Age did not affect the magnitude of generalization of sensorimotor adaptation to untrained vowels.

• Generalization to noncorner vowels was measured under masking noise to prevent online auditory feedback correction.
• Older and younger speakers showed equivalent generalization of learning across the vowel space.
• Age was examined as a continuous variable across the full age range of participants (18–73 years).

Age-related deficits in speech motor performance were an established concern motivating the study, but healthy aging per se was hypothesized to potentially impair speech motor learning.

• Prior research on sensorimotor adaptation in speech has largely focused on younger adults.
• Established age-related deficits in speech motor performance raised the possibility that healthy aging could negatively impact speech motor learning.
• The potential effects of age on sensorimotor adaptation magnitude and generalization were described as 'currently unknown' prior to this study.

The findings support the use of sensorimotor adaptation as a therapeutic mechanism for older adults with acquired motor speech disorders.

• The authors conclude that sensorimotor adaptation can be leveraged to drive 'behaviorally relevant changes in speech in older adults with acquired motor speech disorders.'
• The centralization paradigm produces changes in vowel contrast relevant to speech intelligibility.
• The preservation of adaptation and generalization in healthy aging is described as 'further establishing' the clinical potential of this approach.