Impact of speech rate on perception of vowel and consonant duration by bilinguals and monolinguals.

The perceptual boundary between short and long categories depends on speech rate. We investigated the influence of speech rate on perceptual boundaries for short and long vowel and consonant contrasts by Spanish-English bilingual listeners and English monolinguals. Listeners tended to adapt their perceptual boundaries to speech rates, but the strategy differed between groups, especially for consonants. Understanding the factors that influence auditory processing in this population is essential for developing appropriate assessments of auditory comprehension. These findings have implications for the clinical care of older populations whose ability to rely on spectral and/or temporal information in the auditory signal may decline.

Pedagogical Approaches to Cultural and Linguistic Diversity in Communication Sciences and Disorders Programs: A Nationwide Survey.

PURPOSE: This study investigates how instructors in communication sciences and disorders (CSD) programs teach about cultural and linguistic diversity (CLD) in general-content courses as well as those dedicated to CLD content with the goal of identifying ways of improving training of preservice clinicians to provide culturally responsive service delivery. METHOD: A survey was sent to 4,192 instructors in CSD programs at 295 institutions in the United States and Puerto Rico, of which 565 responded. The survey contained choice response questions and open-ended questions. RESULTS: Curricular infusion as the sole strategy of CLD training has decreased since a similar survey was published by Stockman et al. (2008), while the number of programs that offer courses dedicated to CLD or use both strategies has increased. Dedicated CLD courses offer broader training in CLD issues and are considered more effective at preparing students to work with CLD populations. A number of challenges were identified, such as a lack of available resources or time to cover CLD issues. CONCLUSIONS: A combination of curricular infusion and dedicated CLD coursework is recommended to ensure sufficient training in CLD issues. The development of additional resources is needed to better support instructors in both general-content and CLD-dedicated courses. Finally, CLD training should engage students in challenging unjust systems and harmful ideologies and not just celebrate multiculturalism in order to provide culturally responsive service to all clients. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25587651.

Sensory processing of native and non-native phonotactic patterns in the alpha and beta frequency bands.

The phonotactic patterns of one's native language are established within cortical network processing during development. Sensory processing of native language phonotactic patterns established in memory may be modulated by top-down signals within the alpha and beta frequency bands. To explore sensory processing of phonotactic patterns in the alpha and beta frequency bands, electroencephalograms (EEGs) were recorded from native Polish and native English-speaking adults as they listened to spoken nonwords within same and different nonword pairs. The nonwords contained three phonological sequence onsets that occur in the Polish and English languages (/pət/, /st/, /sət/) and one onset sequence /pt/, which occurs in Polish but not in English onsets. Source localization modeling was used to transform 64-channel EEGs into brain source-level channels. Spectral power values in the low frequencies (2-29 Hz) were analyzed in response to the first nonword in nonword pairs within the context of counterbalanced listening-task conditions, which were presented on separate testing days. For the with-task listening condition, participants performed a behavioral task to the second nonword in the pairs. For the without-task condition participants were only instructed to listen to the stimuli. Thus, in the with-task condition, the first nonword served as a cue for the second nonword, the target stimulus. The results revealed decreased spectral power in the beta frequency band for the with-task condition compared to the without-task condition in response to native language phonotactic patterns. In contrast, the task-related suppression effects in response to the non-native phonotactic pattern /pt/ for the English listeners extended into the alpha frequency band. These effects were localized to source channels in left auditory cortex, the left anterior temporal cortex and the occipital pole. This exploratory study revealed a pattern of results that, if replicated, suggests that native language speech perception is supported by modulations in the alpha and beta frequency bands.

Perception of temporally contrasted Japanese words by Spanish-English bilinguals and American English monolinguals.

Japanese and English use temporal cues within vowels, suggesting an audio-processing advantage for temporally-cued contrasts, while Spanish does not. Using a categorial AXB discrimination task, this study investigated how American English-speaking monolinguals and early and late Spanish-English bilinguals perceive three types of temporally-contrasting Japanese pairs: vowel length (kado/kaado), consonant length (iken/ikken), and syllable number (hjaku/hijaku). All groups performed worse than Japanese controls for the vowel length and syllable number contrasts, but only early bilinguals differed from controls for consonant length. This research contributes to a better understanding of how the first-learned language influences speech perception in a second language.

Evidence for cognitive and brain reserve supporting executive control of memory in lifelong bilinguals.

Recent bilingualism research attempts to understand whether continually controlling multiple languages provides domain-general benefits to other aspects of cognition. Yet little attention has been given to whether this extends to resistance to proactive interference (PI), which involves the filtering of irrelevant memory traces in order to focus attention on relevant to-be-remembered information. The present study sought to determine whether bilingualism provides benefits to resistance to PI performance and brain structure in regions supporting executive control of memory. Eighty-two younger and older adult participants, half English monolinguals and half highly proficient Spanish-English bilinguals, completed directed forgetting and release from PI tasks and underwent an MRI scan that measured cortical volume, thickness, and white matter integrity. While behavioral performance between bilinguals and monolinguals did not differ, bilinguals displayed thinner cortex in brain regions related to resistance to PI, providing evidence for cognitive reserve, and showed positive relationships between white matter integrity and resistance to PI performance, indicative of brain reserve. This study is the first to demonstrate cognitive reserve and brain reserve in different brain structure indices within the same healthy participants and suggests that bilingualism supports important structural relationships between regions necessary for executive control of memory.

Production of Inflected Novel Words in Older Adults With and Without Dementia.

While cognitive changes in aging and neurodegenerative disease have been widely studied, language changes in these populations are less well understood. Inflecting novel words in a language with complex inflectional paradigms provides a good opportunity to observe how language processes change in normal and abnormal aging. Studies of language acquisition suggest that children inflect novel words based on their phonological similarity to real words they already know. It is unclear whether speakers continue to use the same strategy when encountering novel words throughout the lifespan or whether adult speakers apply symbolic rules. We administered a simple speech elicitation task involving Finnish-conforming pseudo-words and real Finnish words to healthy older adults, individuals with mild cognitive impairment, and individuals with Alzheimer's disease (AD) to investigate inflectional choices in these groups and how linguistic variables and disease severity predict inflection patterns. Phonological resemblance of novel words to both a regular and an irregular inflectional type, as well as bigram frequency of the novel words, significantly influenced participants' inflectional choices for novel words among the healthy elderly group and people with AD. The results support theories of inflection by phonological analogy (single-route models) and contradict theories advocating for formal symbolic rules (dual-route models).

Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed.

OBJECTIVES: To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether (a) these domains show different associations with age and education, (b) these domains show similar patterns of age-related change over time, and (c) education moderates the rate of decline in these domains. METHOD: We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education. RESULTS: We identified 2 language domains, that is, semantic control and semantic memory efficiency, and 2 cognitive domains, that is, working memory and cognitive speed. Older age negatively affected all domains except semantic memory efficiency, and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain. DISCUSSION: Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.

Lexical Decision Task for Studying Written Word Recognition in Adults with and without Dementia or Mild Cognitive Impairment.

Older adults are slower at recognizing visual objects than younger adults. The same is true for recognizing that a letter string is a real word. People with Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI) demonstrate even longer responses in written word recognition than elderly controls. Despite the general tendency towards slower recognition in aging and neurocognitive disorders, certain characteristics of words influence word recognition speed regardless of age or neuropathology (e.g., a word's frequency of use). We present here a protocol for examining the influence of lexical characteristics on word recognition response times in a simple lexical decision experiment administered to younger and older adults and people with MCI or AD. In this experiment, participants are asked to decide as quickly and accurately as possible whether a given letter string is an actual word or not. We also describe mixed-effects models and principal components analysis that can be used to detect the influence of different types of lexical variables or individual characteristics of participants on word recognition speed.

The Role of Executive Functions in Object- and Action-Naming among Older Adults.

Background/Study Context: Lexical retrieval abilities and executive function skills decline with age. The extent to which these processes might be interdependent remains unknown. The aim of the current study was to examine whether individual differences in three executive functions (shifting, fluency, and inhibition) predicted naming performance in older adults. Methods: The sample included 264 adults aged 55-84. Six measures of executive functions were combined to make three executive function composites scores. Lexical retrieval performance was measured by accuracy and response time on two tasks: object naming and action naming. We conducted a series of multiple regressions to test whether executive function performance predicts naming abilities in older adults. Results: We found that different executive functions predicted naming speed and accuracy. Shifting predicted naming accuracy for both object and action naming while fluency predicted response times on both tests as well as object naming accuracy, after controlling for education, gender, age, working memory span, and speed of processing in all regressions. Interestingly, inhibition did not contribute to naming accuracy or response times on either task. Conclusion: The findings support the notion that preservation of some executive functions contributes to successful naming in older adults and that different executive functions are associated with naming speed and accuracy.

Effects of morphological family on word recognition in normal aging, mild cognitive impairment, and Alzheimer's disease.

Reading a word activates morphologically related words in the mental lexicon. People with Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI) often have difficulty retrieving words, though the source of this problem is not well understood. To better understand the word recognition process in aging and in neurodegenerative disorders such as MCI and AD, we investigated the nature of the activation of morphologically related family members in 22 Finnish speakers with AD, 24 with MCI, and 17 cognitively healthy elderly. We presented Finnish monomorphemic (base form) nouns in a single-word lexical decision experiment to measure the speed of word recognition and its relation to morphological and lexical variables. Morphological variables included morphological family size (separate for compounds and derived words) and pseudo-morphological family size (including the set of words that have a partially overlapping form but that do not share an actual morpheme, e.g., pet and carpet, or corn and corner). Pseudo-morphological family size was included to examine the influence of words with orthographic (or phonological) overlap that are not semantically related to the target words. Our analyses revealed that younger and elderly controls and individuals with MCI or AD were influenced by true morphological overlap (overlapping forms that also share meaning), as well as by the word's pseudo-morphological family. However, elderly controls and individuals with MCI or AD seemed to rely more on form overlap than young adults. This demonstrates that an increased reliance on form-based aspects of language processing in Alzheimer's disease is not necessarily due to a partial loss of access to semantics, but might be explained in part by a common age-related change of processes in written word recognition.

How older adults use cognition in sentence-final word recognition.

This study examined the effects of executive control and working memory on older adults' sentence-final word recognition. The question we addressed was the importance of executive functions to this process and how it is modulated by the predictability of the speech material. To this end, we tested 173 neurologically intact adult native English speakers aged 55-84 years. Participants were given a sentence-final word recognition test in which sentential context was manipulated and sentences were presented in different levels of babble, and multiple tests of executive functioning assessing inhibition, shifting, and efficient access to long-term memory, as well as working memory. Using a generalized linear mixed model, we found that better inhibition was associated with higher accuracy in word recognition, while increased age and greater hearing loss were associated with poorer performance. Findings are discussed in the framework of semantic control and are interpreted as supporting a theoretical view of executive control which emphasizes functional diversity among executive components.