Typically, understanding speech seems effortless and automatic. However, a variety of factors may, independently or interactively, make listening more effortful. Physiological measures may help to distinguish between the application of different cognitive mechanisms whose operation is perceived as effortful. In the present study, physiological and behavioral measures associated with task demand were collected along with behavioral measures of performance while participants listened to and repeated sentences. The goal was to measure psychophysiological reactivity associated with three degraded listening conditions, each of which differed in terms of the source of the difficulty (distortion, energetic masking, and informational masking), and therefore were expected to engage different cognitive mechanisms. These conditions were chosen to be matched for overall performance (keywords correct), and were compared to listening to unmasked speech produced by a natural voice. The three degraded conditions were: (1) Unmasked speech produced by a computer speech synthesizer, (2) Speech produced by a natural voice and masked byspeech-shaped noise and (3) Speech produced by a natural voice and masked by two-talker babble. Masked conditions were both presented at a -8 dB signal to noise ratio (SNR), a level shown in previous research to result in comparable levels of performance for these stimuli and maskers. Performance was measured in terms of proportion of key words identified correctly, and task demand or effort was quantified subjectively by self-report. Measures of psychophysiological reactivity included electrodermal (skin conductance) response frequency and amplitude, blood pulse amplitude and pulse rate. Results suggest that the two masked conditions evoked stronger psychophysiological reactivity than did the two unmasked conditions even when behavioral measures of listening performance and listeners’ subjective perception of task demand were comparable across the three degraded conditions.

Purpose In Parkinson's disease (PD), there are significant changes in the basal ganglia, a structure known to be important for controlling automatic responses to cues. Changes to the basal ganglia in PD impair an individual's ability to trigger a behavior in response to cues, but more so in response to internal cue s more than external ones. Filled pauses are considered a subconscious or automatic speech response to an internal cue that there are difficulties with ongoing communication. Typical speakers use filled pauses (such as uh or um ) to mark silent pauses. The purpose of this study was to examine how automatic speech responses are impacted in PD by looking at filled and silent pausing behaviors, extending our understanding of the role of the basal ganglia in automatic behaviors. We hypothesized that individuals with PD would use fewer filled pauses and longer silent pauses. We also hypothesized that longer pauses would be more likely to be marked with filled pauses and that this relationship would be weaker in speakers with PD. Method Speech samples were collected via a story-retelling task from 15 individuals with PD and 18 age-matched controls. Duration and frequency of filled and silent pauses were measured using spectrographic analysis. Number and duration of marked silent pauses (those consecutive with 1 or more filled pauses) were measured. The t tests and analyses of variance were used to test our hypotheses. Results There was no significant difference in the number of silent pauses between groups, but the duration of silent pauses was significantly greater for individuals with PD. Despite this, individuals with PD produced significantly fewer filled pauses and fewer marked silent pauses. For both groups, longer silent pauses were more likely to be marked by filled pauses, but individuals with PD marked a smaller percentage of silent pauses at longer durations than controls. Conclusions Producing fewer marked silent pauses, coupled with longer silent pauses, reduces natural cues to discourse and puts people with PD at greater risk of sounding unnatural and losing their communicative turn. These results suggest that automatic responses regarding speech production difficulties are impaired by PD. This interpretation fits with nonspeech literature where automatic responses have been demonstrated to be impaired in PD.

Background: Swallowing disorders (dysphagia) can negatively impact quality of life and health. For clinicians and researchers seeking to improve outcomes for patients with dysphagia, understanding the neural control of swallowing is critical. The role of gray matter in swallowing control has been extensively documented, but knowledge is limited regarding the contributions of white matter. Our aim was to identify, evaluate, and summarize the populations, methods, and results of published articles describing the role of white matter in neural control of swallowing.Methods: We completed a systematic review with a multi-engine search following PRISMA-P 2015 standards. Two authors screened articles and completed blind full-text review and quality assessments using an adapted U.S. National Institute of Health's Quality Assessment. The senior author resolved any disagreements. Qualitative synthesis of evidence was completed.Results: The search yielded 105 non-duplicate articles, twenty-two of which met inclusion criteria. Twenty were rated as Good (5/22; 23%) or Fair (15/22; 68%) quality. Stroke was the most represented diagnosis (n = 20; 91%). All studies were observational, and half were retrospective cohort design. The majority of studies (13/22; 59%) quantified white matter damage with lesion-based methods, whereas 7/22 (32%) described intrinsic characteristics of white matter using methods like fractional anisotropy. Fifteen studies (68%) used instrumental methods for swallowing evaluations. White matter areas commonly implicated in swallowing control included the pyramidal tract, internal capsule, corona radiata, superior longitudinal fasciculus, external capsule, and corpus callosum. Additional noteworthy themes included: severity of white matter damage is related to dysphagia severity; bilateral white matter lesions appear particularly disruptive to swallowing; and white matter adaptation can facilitate dysphagia recovery. Gaps in the literature included limited sample size and populations, lack of in-depth evaluations, and issues with research design.Conclusion: Although traditionally understudied, there is sufficient evidence to conclude that white matter is critical in the neural control of swallowing. The reviewed studies indicated that white matter damage can be directly tied to swallowing deficits, and several white matter structures were implicated across studies. Further well-designed interdisciplinary research is needed to understand white matter's role in neural control of normal swallowing and in dysphagia recovery and rehabilitation.

Older adults often have difficulty understanding speech in background noise, and this difficulty may be associated with cognitive processing demand. According to the effortfulness hypothesis, even sub-clinical age-related changes in hearing may increase cognitive demand for speech understanding, making listening in noise more effortful for older adults even when recognition performance is comparable to that of younger listeners. Separating speech from background noise requires both segregating target from masking signals and selectively attending to the target while ignoring maskers. While both segregation and selection may demand cognitive resources, it is not known whether both mechanisms interact with age to the same degree. To address this question, younger and older adults listened to and repeated sentences presented in quiet and under conditions that put relatively more emphasis on segregation (energetic masking using speech-shaped broad-band noise) or selection (informational masking using two-talker babble) or are cognitively demanding without masking (synthetic speech). Masked stimuli were equally intelligible based on prior research, so differences in listening effort may be attributed to age and/or masker type. Listening effort was measured behaviorally via traditional rating scales (NASA TLX), and psychophysiologically in terms of autonomic nervous system responses (heart rate, pulse period, and amplitude, and skin conductance).

Differences in attentional orienting and regulation of arousal are frequently comorbid traits in many clinical populations including those with autism. The Arousal Biased Competition theory has shown that arousal strengthens pre-existing biases for the perception and memory of objects and may also influence the effectiveness of attentional orienting systems more generally. In order to investigate this possibility, 38 typically developing participants completed both pro- and antisaccade gap-overlap paradigms at multiple levels of autonomic arousal induced by varying levels of background noise and recorded using skin conduction level (SCL). Participants also completed the Autism Spectrum Quotient (AQ) and were assigned to either a high or low AQ group. Linear mixed effects modeling analysis showed several significant interactions between SCL and AQ with Task (prosaccade vs. antisaccade) and Trial Type (gap vs. overlap). We interpret these results as suggesting that arousal improves the effectiveness of top-down (endogenous) attentional mechanisms but notably this impact was weaker for individuals in the high AQ group. Thus, while arousal appears to play an important role in upregulating top-down control, this influence may be altered in autism.