Effects of Task Demands on Neural Correlates of Acoustic and Semantic Processing in Challenging Listening Conditions.

Purpose Listeners shift their listening strategies between lower level acoustic information and higher level semantic information to prioritize maximum speech intelligibility in challenging listening conditions. Although increasing task demands via acoustic degradation modulates lexical-semantic processing, the neural mechanisms underlying different listening strategies are unclear. The current study examined the extent to which encoding of lower level acoustic cues is modulated by task demand and associations with lexical-semantic processes. Method Electroencephalography was acquired while participants listened to sentences in the presence of four-talker babble that contained either higher or lower probability final words. Task difficulty was modulated by time available to process responses. Cortical tracking of speech-neural correlates of acoustic temporal envelope processing-were estimated using temporal response functions. Results Task difficulty did not affect cortical tracking of temporal envelope of speech under challenging listening conditions. Neural indices of lexical-semantic processing (N400 amplitudes) were larger with increased task difficulty. No correlations were observed between the cortical tracking of temporal envelope of speech and lexical-semantic processes, even after controlling for the effect of individualized signal-to-noise ratios. Conclusions Cortical tracking of the temporal envelope of speech and semantic processing are differentially influenced by task difficulty. While increased task demands modulated higher level semantic processing, cortical tracking of the temporal envelope of speech may be influenced by task difficulty primarily when the demand is manipulated in terms of acoustic properties of the stimulus, consistent with an emerging perspective in speech perception.

Neural Processes Underlying Nonword Rhyme Differentiate Eventual Stuttering Persistence and Recovery.

Purpose Phonological skills have been associated with developmental stuttering. The current study aimed to determine whether the neural processes underlying phonology, specifically for nonword rhyming, differentiated stuttering persistence and recovery. Method Twenty-six children who stutter (CWS) and 18 children who do not stutter, aged 5 years, completed an auditory nonword rhyming task. Event-related brain potentials were elicited by prime, rhyming, and nonrhyming targets. CWS were followed longitudinally to determine eventual persistence (n = 14) or recovery (n = 12). This is a retrospective analysis of data acquired when all CWS presented as stuttering. Results CWS who eventually recovered and children who do not stutter exhibited the expected rhyme effect, with larger event-related brain potential amplitudes elicited by nonrhyme targets compared to rhyme targets. In contrast, CWS who eventually persisted exhibited a reverse rhyme effect, with larger responses to rhyme than nonrhyme targets. Conclusions These findings suggest that CWS who eventually persisted are not receiving the same benefit of phonological priming as CWS who eventually recovered for complex nonword rhyming tasks. These results indicate divergent patterns of phonological processing in young CWS who eventually persisted, especially for difficult tasks with limited semantic context, and suggest that the age of 5 years may be an important developmental period for phonology in CWS. Supplemental Material https://doi.org/10.23641/asha.12682874.

Cultural Adaptation of a Neurobiologically Informed Intervention in Local and International Contexts.

The relationship between early adversity and numerous negative outcomes across the lifespan is evident in a wide range of societies and cultures (e.g., Pakulak, Stevens, & Neville, 2018). Among the most affected neural systems are those supporting attention, self-regulation, and stress regulation. As such, these systems represent targets for neurobiologically informed interventions addressing early adversity. In prior work with monolingual native English-speaking families, we showed that a two-generation intervention targeting these systems in families improves outcomes across multiple domains including child brain function for selective attention (for detail, see Neville et al., 2013). Here, we discuss the translation and cultural adaptation (CA) of this intervention in local and international contexts, which required systematic consideration of cultural differences that could affect program acceptability. First, we conducted a translation and CA of our program to serve Latino families in the United States using the Cultural Adaptation Process (CAP), a model that works closely with stakeholders in a systematic, iterative process. Second, to implement the adapted program in Medellín, Colombia, we conducted a subsequent adaptation for Colombian culture using the same CAP. Our experience underscores the importance of consideration of cultural differences and a systematic approach to adaptation before assessing the efficacy of neurobiologically informed interventions in different cultural contexts.