Acoustic Features of Emotional Speech in the Older and Younger Female Adults: Pitch, Intensity, and Utterance Duration in Positive Response Speech Acts

Speechreading and Aging

ABSTRACTMeaningful intergenerational interactions between older and younger adults are rare outside of family relationships. Interventions to increase positive intergenerational interactions are growing, but finding appropriate measures of attitudes toward both younger and older age groups is difficult. Many measures assessing attitudes toward older adults can remind participants of negative stereotypes of aging and are rarely used to assess attitudes toward younger adults. We adapted Pittinsky, Rosenthal, and Montoya’s allophilia measure to assess attitudes toward younger (18–25 years old) and older (over age 65) adults. In the first study, 94 traditional college age and 52 older adults rated older and younger adults. The allophilia measure distinguished between younger and older adults’ attitudes toward each age group. In the second study, we compared the age-related allophilia measures with seven traditional measures of attitudes toward older adults. Forty-seven traditional college age students completed measures. As predicted, correlations between allophilia toward older adults and the traditional semantic differential measures were weak (i.e., r = |0.15|or less), whereas correlations with general attitudes toward older adults were more moderate (r = 0.59 or less). Correlations between allophilia toward younger adults and the traditional measures were primarily non-significant as predicted. The allophilia measure differentiated between the five domains of positive attitudes toward younger and older adults and was not highly correlated with measures of more negative attitudes toward older adults. Results suggest that the allophilia measure can fill a need for a measure of positive attitudes toward older and younger adults.

Functional Assessment in Younger and Older Adults with Sickle Cell Disease

High Diagnostic Uncertainty and Inaccuracy in Adult Emergency Department Patients With Dyspnea: A National Database Analysis.

Effective processing of multisensory stimuli relies on both the peripheral sensory organs and central processing in subcortical and cortical structures. As we age, there are significant changes in all sensory systems and a variety of cognitive functions. Visual acuity tends to decrease and hearing thresholds generally increase (Kalina 1997; Liu and Yan 2007), whereas performance levels on tasks of motor speed, executive function, and memory typically decline (Rapp and Heindel 1994; Birren and Fisher 1995; Rhodes 2004). There are also widespread changes in the aging brain, including reductions in gray and white matter volume (Good et al. 2001; Salat et al. 2009), alterations in neurotransmitter systems (Muir 1997; Backman et al. 2006), regional hypoperfusion (Martin et al. 1991; Bertsch et al. 2009), and altered patterns of functional activity during cognitive tasks (Cabeza et al. 2004; Grady 2008). Given the extent of age-related alterations in sensation, perception, and cognition, as well as in the anatomy and physiology of the brain, it is not surprising that multisensory integration also changes with age.Several early studies provided mixed results on the differences between multisensory processing in older and younger adults (Stine et al. 1990; Helfer 1998; Strupp et al. 1999; Cienkowski and Carney 2002; Sommers et al. 2005). For example, Stine and colleagues (1990) reported that although younger adults’ memory for news events was better after audiovisual presentation than after auditory information alone, older adults did not show improvement during the multisensory conditions. In contrast, Cienkowski and Carney (2002) demonstrated that audiovisual integration on the McGurk illusion was similar for older and younger adults, and that in some conditions, older adults were even more likely to report the fusion of visual and auditory information than their young counterparts. Similarly, in a study examining the contribution of somatosensory input to participants’ perception of visuospatial orientation, Strupp et al. (1999) reported an age-related increase in the integration of somatosensory information into the multisensory representation of body orientation.Despite providing a good indication that multisensory processing is somehow altered in aging, the results of these studies are somewhat difficult to interpret due to their use of complex cognitive tasks and illusions, and to the variability in analysis methods. Several newer studies that have attempted to address these factors more clearly demonstrate that multisensory integration is enhanced in older adults (Laurienti et al. 2006; Peiffer et al. 2007; Diederich et al. 2008).On a two-choice audiovisual discrimination task, Laurienti and colleagues (2006) showed that response time (RT) benefits for multisensory versus unisensory targets were larger for older adults than for younger adults (Figure 20.1). That is, older adults’ responses during audiovisual conditions were speeded more than younger adults’, when compared with their respective responses during unisensory conditions. Multisensory gains in older adults remained significantly larger than those observed in younger adults, even after controlling for the presence of two targets in the multisensory condition (redundant target effect; Miller 1982, 1986; Laurienti et al. 2006).Using similar analysis methods, Peiffer et al. (2007) also reported increased multisensory gains in older adults. On a simple RT task, where average unisensory RTs were equivalent in younger and older adults, older adults actually responded faster than younger adults on multisensory trials because of their enhanced multisensory integration (Peiffer et al. 2007). Diederich and colleagues (2008) have also shown that older adults exhibit greater speeding of responses to multisensory targets than younger adults on a saccadic RT task. The analysis methods used in this experiment indicate a slowing of peripheral sensory processing, as well as a wider time window over which integration of auditory and visual stimuli can occur (Diederich et al. 2008).These experiments highlight several possible explanations that could help answer a critical question about multisensory processing in aging: Why do older adults exhibit greater integration of multisensory stimuli than younger adults? Potential sources of enhanced integration in older adults include age-related cognitive slowing not specific to multisensory processing, inverse effectiveness associated with sensory deficits, alterations in the temporal parameters of integration, and inefficient top–down modulation of sensory processing. In the following sections we will investigate each of these possible explanations in greater detail and offer some alternative hypotheses for the basis of enhanced multisensory integration in older adults.

The hyperemic response to passive leg movement (PLM) is largely (~80%) nitric oxide (NO) mediated in young adults, whereas both the overall response and NO contribution (~20%) are diminished in older adults. A transient hyperemic response remains in both groups after NO blockade, however, the mechanisms contributing to this remaining response are unknown. Vasodilatory substances including prostaglandins (PG) and endothelial derived hyperpolarizing factors (EDHF) are primary candidates contributing to PLM response. Moreover, these underlying mechanisms of the PLM response are likely influenced by exercise training in both young and older adults but this remains to be determined. Thus, we sought to determine if 1) PG and EDHF contribute to the hyperemic response in older adults, and 2) exercise training alters the mechanisms contributing to changes in PLM (i.e., NO, PG, or EDHF). The leg blood flow (LBF) response to PLM was measured by Doppler ultrasound in 9 young (25±4 yr) and 9 older (69±5 yr) adult males. PLM was performed with intra-arterial infusions of saline (control), NG-monomethyl-L-arginine (L-NMMA) to inhibit NOS and NO production, and a combination of L-NMMA, ketorolac tromethamine (KET) to inhibit cyclooxygenase and PG production, and fluconazole (FLUC) to inhibit cytochrome P-450 and EDHF (L-NMMA+KET+FLUC). This PLM and drug infusion protocol were repeated following 8 weeks of single leg knee-extension (KE) exercise training to determine if the vasodilatory mechanisms regulating PLM-induced hyperemia are altered by exercise training. The hyperemic response to PLM (total LBF area under the curve) was significantly attenuated from control with infusion of L-NMMA in young adults (-287±280 mL, p<0.05) but remained unchanged in the older (-55±86 mL, P=0.70). Combined infusion of L-NMMA+KET+FLUC yielded similar results such that PLM decreased to the same degree as L-NMMA in young (-276±108 mL, p<0.05) with no significant change in older adults (-116±81 mL, P=0.36). Following 8 weeks of single leg KE training, maximal power (KEmax) improved in both young (+33±13 W, p<0.05) and older adults (+16±8 W, p<0.05). Despite improvements in KEmax, the hyperemic response to PLM only increased in young adults by ~30% (454±194 v. 604±351 mL, p<0.05), while no improvement was observed in older adults (225±142 v. 236±89 mL, P=0.86). The contribution of NO to PLM did not change following exercise training in either young (-238±217 mL, P=0.14) or older (-62±82 mL, P=0.72) adults. Likewise, the contribution of PG and EDHF also did not change in both young (-306±222 mL, P=0.68) and older (-108±116 mL, P=0.77) adults. These findings indicate that PG and EDHF do not have an additive effect to NO on the hyperemic response to PLM in both young and older adults. Therefore, the remaining hyperemic response following combined NO, PG, and EDHF inhibition is likely driven by non-endothelial dependent mechanisms. Moreover, these data indicate that 8 weeks of KE specific exercise training significantly improves the hyperemic response to PLM in young but not older adults. Interestingly, the observed improvements to PLM were not directly mediated through the NO, PG, or EDHF pathways but by some other, currently unidentified, mechanism. National Institutes of Health R01HL142603 (to J.D. Trinity) This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

BackgroundCardiovascular diseases (CVDs) are a major cause of morbidity and mortality worldwide, with data showing an increasing trend. Previously uncommon, CVDs of lifestyle are now increasing in many Sub-Sahara African (SSA) countries including Tanzania. The study aimed at determining the spectrum and distribution of CVDs among young (< 45 years) and older (≥ 45 years) adults referred for echocardiography at Jakaya Kikwete Cardiac Institute (JKCI).MethodsHospital-based cross sectional study was conducted among adult patients referred for echocardiography at JKCI between July and December 2021. Patient’s socio-demographic and clinical characteristics were recorded. CVD diagnoses were made using established diagnostic criterias. Comparisons were done using chi-square test and student’s t-test. Multivariable logistic regression analysis was used to determine factors associated with abnormal echocardiography. A significance level was set at p-value < 0.05.ResultsIn total 1,050 patients (750 old and 300 young adults) were enrolled. The mean ± SD age was 62.2 ± 10.4 years and 33.5 ± 7.4 years for older and young adults respectively. Hypertension was the commonest indication for echocardiography both in the young (31%) and older (80%) adults. Majority of older adults were found to have abnormal echocardiography (90.7%), while only 44.7% of the young adults had abnormal echocardiography (p < 0.001). For the older adults, the commonest diagnoses were HHD (70.3%), IHD (9.7%), and non-ischemic cardiomyopathy (6.1%) while for young adults, HHD (16.7%), non-ischemic cardiomyopathy (8%), RHD (8%) and MVP (4.3%) were the commonest. The differences in the echocardiographic diagnoses between young and older adults were statistically significant, p < 0.001. Being an older adult, hypertensive, overweight/obese were independently associated with abnormal echocardiography (p < 0.01).ConclusionHypertensive heart disease is the most common diagnosis among adult patients referred for echocardiography at JKCI, both in young and older adults. Primary prevention, early detection and treatment of systemic hypertension should be reinforced in order to delay or prevent its complications.

Objective:Epilepsy is the third most common neurological disorder among older adults, and as adults are living longer, the incidence of epilepsy is increasing (Kun Lee, 2019). The purpose of this study is to examine 1. differences in quality of life (QOL) between older and younger adults with medically intractable epilepsy and 2. the impact of seizure frequency, seizure duration, depression, sex, and marital status on QOL. Given differences in the prevalence rates of depression between men and women and importance of depression in QOL, we predicted that sex and marital status would moderate the effect of depression on total QOL (TQOL).Hypothesis I: Compared to younger adults, older adults with epilepsy will report lower TQOL scores and lower scores on subscales measuring energy/fatigue, cognition, and medication effects. Hypothesis II: Seizure variables and depression will significantly account for TQOL scores in both groups (younger and older) above demographic variables (sex, marital status, and education). Hypothesis III: Sex will moderate the effect of depression in both groups and marital status will moderate the effect of depression only in the older adults.Participants and Methods:Participants were 607 adults (&gt; 18 years old) who were prospective candidates for epilepsy surgery and underwent a comprehensive neuropsychological evaluation including QOL assessment using the Quality of Life in Epilepsy Scale-31 (QOLIE-31). Individuals were grouped by older (&gt; 50 years old; N = 122) and younger adults (&lt; 50 years old; N = 485). Hierarchical regression was used to examine the proposed associations.Results:Hypothesis I: In contrast to our hypothesis, a one-way ANOVA did not reveal significant differences between the older and younger groups on the QOL subscales, TQOL, or depression.Hypothesis II: For older adults, longer seizure duration was associated with better TQOL; bivariate correlations showed no evidence of statistical suppression. Higher depression scores were associated with worse TQOL. Overall, the model accounted for 39.6% of variance among older adults. For younger adults, only depression was a significant predictor of TQOL wherein higher depression scores were associated with worse TQOL. Overall, the model accounted for 36.1% of the variance among younger adults. Hypothesis III: There was no moderation between depression and marital status in older or younger adults (b = -.009, p &gt; .05). There was multicollinearity evidenced by VIF (variance inflation factor) greater than 10, so the associations between depression and sex could not be examined.Conclusions:Overall, there were no significant differences between QOL in younger versus older adults. Greater depression symptoms were associated with lower TQOL in both groups. Longer seizure duration was a significant predictor of better TQOL in older adults only, perhaps indicating better adjustment to having a seizure disorder with longer duration of epilepsy. Lastly, marital status did not moderate the effects of depression on TQOL and the moderating effects of sex on TQOL could not be assessed due to multicollinearity. Study limitations include dichotomizing the sample into these particular age groups and the heterogeneity of seizure types.

Preferred and maximum walking speeds decline as we age, and the decline has been associated with worsening health. Slowing of gait in older individuals is correlated with biomechanical and neural factors, but historically it has been difficult to measure whole brain activity during walking. Recent advances in mobile brain imaging with high-density electroencephalography (EEG) allow for separation and localization of electrical brain activity during walking. We studied younger (N = 31) and older (N = 59) adults walking on a treadmill at different speeds (0.25-1.0 m/s) while we recorded electrocortical dynamics with EEG. We hypothesized that faster walking speeds would result in greater sensorimotor and posterior parietal theta-band (4-7 Hz) spectral power and lower beta-band (13-30 Hz) spectral power compared to slower walking speeds for older adults, consistent with previous studies on younger adults. Additionally, we used a standardized test of physical function to group older adults into high-functioning [Short Physical Performance Battery (SPPB) ≥ 10] and low-functioning (SPPB < 10) groups for comparison. In agreement with our hypotheses, sensorimotor and posterior parietal theta power increased and beta power decreased at faster walking speeds. We also found that left posterior parietal, mid cingulate, and cuneus exhibited differences in theta power at faster speeds between younger and older adults. The results suggest that older and younger adults activate cortical areas throughout the brain while walking at different speeds and older adults, particularly those with lower mobility, recruit greater cognitive resources in parietal cortex compared to younger adults. These results could inform stimulation protocols targeting parietal cortex.NEW & NOTEWORTHY Older and younger adults show widespread EEG beta power decreases at faster walking speeds compared to slower walking speeds. Older adults differentially alter EEG theta power while walking compared to younger adults. Prior studies with functional near-infrared spectroscopy (fNIRS) have documented differences in prefrontal activation in older adults walking compared to younger adults, but our results show cortical changes within speed and age outside of the prefrontal cortex.

Introduction: The use of shared automated vehicles (SAVs) should lead to several societal and individual benefits, including reduced greenhouse gas emissions, reduced traffic, and improved mobility for persons who cannot safely drive themselves. We define SAVs as on-demand, fully automated vehicles in which passengers are paired with other riders traveling along a similar route. Previous research has shown that younger adults are more likely to report using conventional ridesharing services and are more accepting of new technologies including automated vehicles (AVs). However, older adults, particularly those who may be close to retiring from driving, stand to greatly benefit from SAV services. In order for SAVs to deliver on their aforementioned benefits, they must be viewed favorably and utilized. We sought to investigate how short educational and/or experiential videos might impact younger, middle-aged, and older adult respondents’ anticipated acceptance and attitudes toward SAVs. Knowing what types of introductory experiences improve different age groups’ perceptions of SAVs will be beneficial for tailoring campaigns aiming to promote SAV usage. Methods: We deployed an online survey using the platform Prolific for middle-aged and older respondents, and our departmental participant pool for younger adults, collecting 585 total responses that resulted in 448 valid responses. Respondents answered questions regarding their demographic attributes, their ridesharing history, preconceptions of technology, as well as their anticipated acceptance attitudes towards SAVs as measured by the dimensions of the Automated Vehicle User Perception Survey (AVUPS). After this, respondents were randomly assigned to an intervention condition where they either watched 1) an educational video about how SAVs work and their potential benefits, 2) an experiential video showing a AV navigating traffic, 3) both the experiential and educational videos, or 4) a control video explaining how ridesharing works. Anticipated acceptance attitudes towards SAVs were measured again after this intervention and difference scores calculated to investigate the effect of the intervention conditions. Prolific respondents were paid at a rate of $9.50/hour and younger adults received course credit. Results: Controlling for preconceptions of technology and ridesharing experience, a MANOVA was run on the difference scores of the dimensions of the AVUPS (intention to use, trust/reliability, perceived usefulness (PU), perceived ease of use (PEOU), safety, control/driving-efficacy, cost, authority, media, and social influence). Both older and middle-aged adults expressed significantly greater increases in PEOU and PU of SAVs than younger adults. We also observed an interaction between age and condition for both PU and PEOU. For PU, older adults’ difference scores were found to be significantly greater than younger adults’ for the control video condition. With PEOU, older adults’ difference scores were significantly greater than both younger adults’ for the control video condition, and middle-aged adults had greater difference scores for the educational-only video condition than younger or older adults. Discussion: The increases in PU observed for older adults in the control condition suggests that educating them on how to use currently available ridesharing services might transfer to and/or highlight the benefits that automated ridesharing might provide. The PEOU interactions also suggest that middle-aged adults might respond more positively than younger or older adults to an educational introduction to SAVs. Conclusion: The positive findings pertaining to PU and PEOU show that exposure to information related to SAVs has a positive impact on these attitudes. PU’s and PEOU’s positive relationship to behavioral intentions (BI) in the Technology Acceptance Model, coupled with the findings from this study, bode well for higher fidelity interventions seeking to inform and/or give individuals experience with SAVs. Providing information on how currently available ridesharing services work helped our older adult respondents recognize the potential usefulness of SAVs. Knowing that different age groups may respond better to educational versus experiential interventions, for example middle-aged adults in this study responding more positively to the educational video condition than younger or older adults, may be useful for targeted promotional campaigns.

Despite well-documented declines in most cognitive domains, some emotional processes appear to be preserved or even enhanced in late adulthood. A good example of this is the information processing bias older adults show towards positive relative to negative emotional stimuli, often referred to as the age-related positivity effect. The present thesis presents a series of experiments that were designed to better understand the mechanisms that contribute to age-related changes in emotional processing, focusing in particular on the role of cognitive mechanisms and neural networks. In Study 1 aimed to identify the underlying cognitive mechanisms of the positivity effect. The primary focus of this study was to explore the role of distractors during the early attention allocation stage, and to also measure how selective attentional processes during encoding influence later memory outcomes for emotional items. The results showed that consistent with prior literature, a memory positivity effect was found among older relative to younger adults. However, of particular interest was the finding that, participants’ memory for negative targets was not influenced by the presence of positive distractors. This finding suggests that positive distractors did not automatically capture older adults’ attention during encoding for negative items. Importantly, we found that participants’ pupillary responses to negative items mediated the relationship between age and the memory positivity effect, indicating that older adults use their cognitive control resources when encoding negative information, perhaps to down regulate the impact of negative emotions on their memory. Collectively, these two findings provide converging support for the cognitive control account of the positivity effect. Study 2 used a similar paradigm to Study 1 to examine the underlying neural networks involved in processing emotional items during working memory encoding among older and younger adults. Results indicated that a cognitive control network that included fronto-parietal regions, was functionally connected to the left ventrolateral prefrontal cortex during the encoding of negative items among older adults. This network contributed to performance, both accuracy and response times, in older adults’ group. A less distributed network was found for encoding of positive items among older and both items among younger adults. Although older adults recruited a same network that was functionally connected to the amygdala for encoding positive and negative items, younger adults recruited this particular network specifically for encoding negative items. This network facilitated older adults’ higher accuracy and faster response times during retrieval. Taken together, the results from these functional connectivity analyses suggest that there is differential engagement of brain networks connected to these two regions, which are modulated by the emotional valence. While two separate brain networks underlying the encoding of emotionally valence targets are connected to the vlPFC region, one distinct network is functionally connected to the amygdala and subserves the processing of both positive and negative targets. In Study 3 age-related differences in neural substrates involved when processing happy and angry expressions presented with direct versus averted gaze were investigated. This research was motivated by studies that show older adults not only have difficulties processing emotional cues such as facial expression and eye gaze cues, but also have problems integrating these cues. Study 3 provides the first empirical examination of the underlying neural correlates of age-related difficulties in integrating communicative cues. The results showed that for angry facial expressions, younger adults recruited distinct networks while processing direct versus averted eye-gaze cues, however, older adults showed a lack of neural sensitivity to these cues, recruiting a single network for both types of stimuli. In contrast, for happy facial expressions, only older adults showed neural sensitivity to eye gaze cues. Participants’ performance on the scanner task was then correlated with a measure of theory of mind (TOM). Younger (but not older) adults’ performance on a measure of TOM and recognition of angry expressions was differentially correlated with activation in two sets of brain regions as a function of eye gaze. Unlike younger adults, older adults’ performance on TOM was also differentially correlated with the key node of mentalizing brain network during happy expressions as a function of eye gaze. The findings from Study 3 suggest that the age-related difficulties in integrating facial cues could be associated with the recruitment of the mentalizing network when the task imposes high demand on social-cognitive processing. Taken together, the three Studies reported in this thesis provide novel insights into our understanding of age-related differences in the processing of emotionally valenced items, particularly with respect to initial encoding of this information, and how this relates to later memory outcomes. Moreover, for the first time the neural correlates of integrating two important types of facial cue has been identified, and potentially linked to broader social cognitive difficulties. Overall, the findings of this thesis have broad implications for understanding the underlying cognitive mechanisms and neural networks that contribute to age-related differences in the processing of emotional stimuli.

IntroductionPeripheral nervous system feedback arising from mechanically and metabolically sensitive afferents (Group III/IV, respectively) are central components of the exercise pressor reflex. Experimentally, locomotor venous distention can be simulated via subsytolic regional circulatory occlusion (SubRCO) thereby augmenting the exercise pressor reflex. Furthermore, high pedal frequency increases type II muscle fiber recruitment during exercise likely increasing non‐oxidative metabolism. To date, studies investigating the influence of aging on the exercise pressor reflex have presented conflicting data with most utilizing small muscle mass exercise (e.g. handgrip). Therefore, the purpose of this study was to determine the influence of SubRCO, pedal frequency, and the combination thereof on blood pressure (BP) during exercise in older and younger adults. We hypothesized that during exercise 1) independent of pedal frequencies and age, SubRCO will augment BP and 2) older adults will have greater increases in BP at high pedal frequencies with and without SubRCO compared younger adults.Methods10 younger (22±2 yrs; 4M/6W; 24±4 kg/m2) and 10 older (63±10yrs; 4M/6W; 24±4 kg/m2) adults participated in two study visits each consisting of two cycling exercise sessions at 20 W, with bilateral upper thigh pressure cuffs. Participants engaged in 3 minutes of exercise at 35 (LOW) or 100 (HIGH) rpm with 5 additional minutes of exercise at that rpm with no cuffing (CTL) or SubRCO in randomized order. Systolic and diastolic blood pressure (SBP and DBP, respectively) were measured via manual sphygmomanometry. Mean arterial pressure (MAP) was calculated as (SBP‐DBP)/3+DBP and the changes in MAP from rest are reported.ResultsDuring LOW, SubRCO resulted in greater MAP than CTL in younger (CTL: 4±7; SubRCO: 13±7 mmHg) and older adults (CTL: 4±6; SubRCO: 13±4 mmHg) (both p&lt;0.01). During HIGH, SubRCO resulted in greater MAP than CTL in younger (CTL: 7±4; SubRCO: 20±6 mmHg) and older adults (CTL: 20±9; SubRCO: 31±8 mmHg) (both p&lt;0.01). Younger and older adults had greater increases in MAP during HIGH CTL and SubRCO compared to LOW CTL and SubRCO, respectively (all, p&lt;0.01). Within LOW, there were no differences between younger and older adults during CTL or SubRCO (all, p&gt;0.05). Within HIGH, older adults had greater increases in MAP than younger adults during CTL and SubRCO (both p&lt;0.01).ConclusionThese data support the hypothesis that older compared to younger adults have a greater BP response at higher pedal frequencies during exercise. Our results suggest that aging contributes to a greater exercise pressor response to exercise, possibly due to greater feedback from group III/IV afferents.Support or Funding InformationNIH HL126638AHA 18POST3990251This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The sympathetic nervous system is an important regulator of coronary blood flow. The cold pressor test (CPT) is a powerful sympathoexcitatory stressor. We tested the hypotheses that: (1) CPT-induced sympathetic activation elicits coronary vasodilatation in young adults that is impaired with advancing age and (2) combined α- and β-adrenergic blockade diminishes/abolishes these age-related differences. Vascular responses of the left anterior descending artery to the CPT were determined by transthoracic Doppler echocardiography before (pre-blockade) and during (post-blockade) systemic co-administration of α- and β-adrenergic antagonists in young (n = 9; 26 ± 1 years old, mean ± SEM) and older healthy men (n = 9; 66 ± 2 years old). Coronary vascular resistance (CVR; mean arterial pressure/coronary blood velocity) was used as an index of vascular tone. CPT decreased CVR (i.e. coronary vasodilatation occurred) in young ( -33 ± 6%), but not older men ( -3 ± 4%; P < 0.05 vs. young) pre-blockade. Adrenergic blockade abolished CPT-induced coronary vasodilatation in young men ( -33 ± 6% vs. 0 ± 6%, pre-blockade vs. post-blockade, respectively; P < 0.05) such that responses post-blockade mirrored those of older men ( -3 ± 4% vs. 8 ± 9%; both P > 0.05 compared to young pre-blockade). Impaired CPT-induced coronary vasodilatation could not be explained by a reduced stimulus for vasodilatation as group and condition effects persisted when CVR responses were expressed relative to myocardial oxygen demand (rate-pressure product). These data indicate that the normal coronary vascular response to sympathetic activation in young men is pronounced vasodilatation and this effect is lost with age as the result of an adrenergic mechanism. These findings may help explain how acute sympathoexcitation may precipitate angina and coronary ischaemic events, particularly in older adults.

Though some studies suggest that older adults are not differentially impacted by foreign-accented speech relative to younger adults, other studies indicate that older adults are poorer at perceiving foreign-accented speech than younger adults. The present study sought, first, to clarify the extent to which older and younger adults differed in their perception of foreign-accented speech. The secondary aim was to elucidate the extent to which the cognitive mechanisms supporting accented speech perception differ for older and younger adults. The data indicated that older adults were poorer at perceiving accented speech than younger adults. Older adults' speech perception accuracy was associated with a significant main effect of working memory as well as significant interactions between hearing acuity and cognitive flexibility and between hearing acuity and inhibitory control. Younger adults' speech perception accuracy, in contrast, was associated with a significant interaction between hearing acuity and processing speed. It therefore appears that the differences in performance between younger and older adults observed here may be attributable to differences in the cognitive mechanisms that support accented speech perception.

The interaction of the triceps surae muscles and the Achilles tendon is critical in producing the ankle plantarflexion torque required for human walking. Deficits in plantarflexor output are a hallmark of reduced mobility in older adults and are likely associated with changes in the triceps surae muscles that occur with age. Structural differences between young and older adults have been observed in the Achilles tendon and in the triceps surae muscles. However, less is known about how age-related differences in muscle and tendon morphology correspond with each other and, furthermore, how those morphology differences correlate with age-related deficits in function. The goal of this work was to investigate whether there is a correlation between age-related differences in triceps surae muscle size and Achilles tendon cross-sectional area (CSA) and whether either is predictive of ankle plantarflexion torque during walking. We used magnetic resonance imaging (MRI) to measure triceps surae muscle volumes and tendon CSAs in young (n = 14, age: 26 ± 4 years) and older (n = 7, age: 66 ± 5 years) adults, and we determined peak plantarflexion torques during treadmill walking. We found that individual muscle volumes as a percentage of the total triceps surae volume did not differ between young and older adults, though muscle volumes per body size (normalized by the product of height and mass) were smaller in older adults. Achilles tendon CSA was correlated with body size and muscle volumes in young adults but not in older adults. The ratio of tendon CSA to total triceps surae muscle volume was significantly greater in older adults. Peak ankle plantarflexion torque during walking correlated with body size and triceps surae volume in young and older adults but was correlated with tendon CSA only in the young adults. Structure–function relationships that seem to exist between the Achilles tendon and the triceps surae muscles in young adults are no longer evident in all older adults. Understanding mechanisms that determine altered Achilles tendon CSA in older adults may provide insight into age-related changes in function.