Using multivariate partial least squares on fNIRS data to examine load-dependent brain-behaviour relationships in aging.

The present study investigated the ability of older adults in contrast to younger adults to automatize new choice tasks as a result of simultaneous dual-task practice. Importantly, the study was carried out in conditions optimal for dual-task performance and task automatization. Despite this, the results of detailed analyses were not consistent with the assumption that either older or younger adults are able to automatize new choice tasks; neither group showed evidence of automatization. Even in analyses focusing on high dual-task performers (i.e., individuals who performed equally well in single and dual tasks) the results were not consistent with this assumption. Instead, it seems to be the case that both older and younger adults continue to use capacity-limited processes to process choice tasks after dual-task practice. These conclusions are consistent with findings from studies using single-task practice and tests of task automatization in dual tasks (Maquestiaux, Laguë-Beauvais, Ruthruff, Hartley, & Bherer, 2010; Maquestiaux, Didierjean, Ruthruff, Chauvel, & Hartley, 2013). (PsycINFO Database Record

Texting while walking (TeWW) has become common among people of all ages, and mobile phone use during gait is increasingly associated with pedestrian injury. Although dual-task walking performance is known to decline with age, data regarding the effect of age on dual-task performance in ecological settings are limited. The objective of this study was to evaluate the effect of age, environment (indoors/outdoors), and mixed reality (merging of real and virtual environments) on TeWW performance. A cross-sectional design was used. Young (n=30; 27.8±4.4 years) and older (n=20; 68.9±3.9 years) adults performed single- and dual-task texting and walking indoors and outdoors, with and without a mixed reality display. Participants also completed evaluations of visual scanning and cognitive flexibility (Trail Making Test) and functional mobility (Timed "Up & Go" Test). Indoors, similar interference to walking and texting occurred for both groups, but only older adults' gait variability increased under dual task conditions. Outdoors, TeWW was associated with larger age-related differences in gait variability, texting accuracy, and gait dual-task costs. Young adults with better visual scanning and cognitive flexibility performed TeWW with lower gait costs (r=0.52-0.65). The mixed reality display was unhelpful and did not modify walking or texting. Older adults tested in this study were relatively high functioning. Gaze of participants was not directly monitored. Although young and older adults possess the resources necessary for TeWW, older adults pay an additional "price" when dual-tasking, especially outdoors. TeWW may have potential as an ecologically valid assessment and/or an intervention paradigm for dual-task performance among older adults as well as for clinical populations.

Event Abstract Back to Event Individual Differences in Right Dorsolateral Prefrontal Cortex Volumes, Whole Brain Activity and Memory Performance in Healthy Young and Older Adults Y. Czechowska1, C L Grady1, 2, R. Languay1, J C Pruessner1, M N Rajah1* and L. Valiquette1 1 McGill University, Douglas Mental Health University Institute, Canada 2 University of Toronto, Rotman Research Institute at Baycrest, Canada We conducted an fMRI study on 25 young and 26 older healthy adults and reported deficits in right dorsolateral PFC (DLPFC) activity that were linked to context memory reductions deficits in older adults (Rajah et al 2010). To extend this result we conducted semi-automatic volume segmentation of left and right DLFPC in this cohort and found a near significant (p = .055) group-by-hemispheric difference in DLPFC volume, due to older adults exhibiting smaller right versus left DLPFC volumes compared to young adults. To determine if this age-difference in right DLPFC volume was linked with changes in right DLPFC structure-function associations, we conducted a multivariate partial least squares (ST-PLS) seed analysis, using right DLPFC volumes and accuracy scores. One significant effect (p<.001) was indentified, which reflected group differences in the network of brain regions activated in association with correct context retrieval and larger right DLPFC volumes. In young adults improved retrieval accuracy and larger right DLPFC volumes was associated with increased bilateral DLPFC activity and right hippocampal activity. In contrast, in older adults retrieval accuracy and larger right DLPFC volumes was associated with increased activity in left, but not right, DLPFC, bilateral ventrolateral PFC and caudate. This supports the argument that age-related deficits in context memory retrieval may be due to changes in right DLPFC structure, function and its structure-function associations with the retrieval network, including right hippocampus. Conference: The 20th Annual Rotman Research Institute Conference, The frontal lobes, Toronto, Canada, 22 Mar - 26 Mar, 2010. Presentation Type: Poster Presentation Topic: Cognitive Neuroscience Citation: Czechowska Y, Grady C, Languay R, Pruessner J, Rajah M and Valiquette L (2010). Individual Differences in Right Dorsolateral Prefrontal Cortex Volumes, Whole Brain Activity and Memory Performance in Healthy Young and Older Adults. Conference Abstract: The 20th Annual Rotman Research Institute Conference, The frontal lobes. doi: 10.3389/conf.fnins.2010.14.00116 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Jun 2010; Published Online: 30 Jun 2010. * Correspondence: M N Rajah, McGill University, Douglas Mental Health University Institute, Montreal, QC, Canada, maria.rajah@mcgill.ca Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Y. Czechowska C L Grady R. Languay J C Pruessner M N Rajah L. Valiquette Google Y. Czechowska C L Grady R. Languay J C Pruessner M N Rajah L. Valiquette Google Scholar Y. Czechowska C L Grady R. Languay J C Pruessner M N Rajah L. Valiquette PubMed Y. Czechowska C L Grady R. Languay J C Pruessner M N Rajah L. Valiquette Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

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.

Background: Hearing impairments are associated with reduced walking performance under Dual-task (DT) conditions. Little is known about the neural representation of DT performance while walking in this target group compared to healthy controls or younger adults. Therefore, utilizing the Mobile Brain/Body Imaging approach (MoBI), we aim at gaining deeper insights into the brain dynamics underlying the interaction of cognitive and motor processes during different DT conditions (visual and auditory) controlling for age and the potential performance decrements of older adults with hearing impairments.Methods: The cross-sectional study integrates a multifactorial mixed-measure design. Between-subject factors grouping the sample will be age (younger vs. older adults) and hearing impairment (mild vs. not hearing impaired). The within-subject factors will be the task complexity (single- vs. DT) and cognitive task modality (visual vs. auditory). Stimuli of the cognitive task will vary according to the stimulus modality (visual vs. auditory), presentation side (left vs. right), and presentation-response compatibility (ipsilateral vs. contralateral). Analyses of DT costs and underlying neuronal correlates focus either on gait or cognitive performance. Based on an a priori sample size calculation 96 (48 healthy and 48 mildly hearing impaired) community-dwelling older adults (50–70 years) and 48 younger adults (20–30 years) will be recruited. Gait parameters of speed and rhythm will be captured. EEG activity will be recorded using 64 active electrodes.Discussion: The study evaluates cognitive-motor interference (CMI) in groups of young and older adults as well as older adults with hearing impairment. The underlying processes of the interaction between motor and cognitive tasks will be identified at a behavioral and neurophysiological level comparing an auditory or a visual secondary task. We assume that performance differences are linked to different cognitive-motor processes, i.e., stimulus input, resource allocation, and movement execution. Moreover, for the different DT conditions (auditory vs. visual) we assume performance decrements within the auditory condition, especially for older, hearing-impaired adults. Findings will provide evidence of general mechanisms of CMI (ST vs. DT walking) as well as task-specific effects in dual-task performance while over ground walking.

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.

Dual Task Demands and Gist-Based False Recognition of Pictures in Younger and Older Adults

Background/Study Context: Older adults’ peak performance on memory and cognitive inhibition tasks tends to be in the morning, whereas younger adults’ peak performance tends to be in the afternoon. Although these tasks require efficient attentional processes for optimal performance, previous research examining age differences in the effects of time of day has not measured the distinct aspects of attention quantified by the Attention Network Test (ANT; Fan, McCandliss, Sommer, Raz, & Posner, 2002, Journal of Cognitive Neuroscience, 14, 340–347). Methods: The authors examined the relationship between time of testing and the efficiency of alerting, orienting, and executive attention networks by randomly assigning younger (18–28 years; n = 27, M = 21.37 years, SD = 2.39) and older (65–85 years; n = 32, M = 73.34 years, SD = 5.18) adults to morning (AM) or afternoon (PM) testing of alerting, orienting, and executive attention. Mean reaction times for each network were analyzed with a univariate analysis of variance (ANOVA) with age (younger, older) and time of day (AM, PM) as between-subjects factors. Results: Consistent with the authors’ hypotheses, although time of day had little effect on orienting or executive attention, it affected alerting in opposite ways for younger and older adults, with alerting cues benefiting performance most at participants’ off-peak times of day. A larger benefit from alerting cues was observed when participants were tested at their off-peak (M = 30.11 ± 15.66) relative to their peak (M = 2.18 ± 15.97) time. Conclusion: These findings show that age-related circadian patterns influence the alerting component of attention, with both age groups showing the largest benefit from alerting cues when testing occurs at nonoptimal times of day. Overall, these findings underscore the importance of controlling for time of day in investigations of attention and add to our understanding of how age differences in circadian patterns impact attention.

Updating prior information with new information in accordance with Bayesian principles is a difficult task. Younger adult decision makers deviate from Bayes’ theorem by either overweighting prior information (i.e., using a conservatism heuristic) or overweighting new information (i.e., using a representativeness heuristic) on decision tasks without feedback. Similar to younger adults, older adults make decisions that require belief updating. Given agerelated decrements in cognitive control, older adults may be at a disadvantage compared with younger adults when updating beliefs. Prior research shows no age differences when making decisions under risk, however older adults perform worse than younger adults when making decisions under ambiguity. Currently it is unknown how older adults use heuristics when updating beliefs about risk and ambiguous information compared with younger adults. The primary aim of this dissertation was to examine age-related differences in the use of heuristics during belief updating, as well as the cognitive processes and neural correlates that underpin behaviour. In three experiments, younger and older adults completed a belief updating task with and without feedback using an urn-ball paradigm. The main results showed that both younger and older adults committed the representativeness error more than the conservatism error, with no age differences observed when updating beliefs without feedback but with younger adults updating beliefs more accurately than older adults with feedback. Further, age differences in the neural correlates that underlie belief updating showed evidence that older adults recruit additional resources in frontal regions of the brain to facilitate performance compared with younger adults. Event-related potentials showed evidence of cognitive control in response to conflicting information in both age groups, but a diminished neural response to feedback in older compared with younger adults. Additionally, while younger adults were not influenced by ambiguous information, older adults avoided committing the representativeness error only when new information was ambiguous. Last, individual differences in numeracy and cognitive reflection, but not thinking disposition, modulated belief updating performance. Together, the results show that younger and older adults can learn to update beliefs with feedback but with younger adults learning to a greater degree than older adults, especially when information is ambiguous.

Biomechanics of sit-to-stand with dual tasks in older adults with and without mild cognitive impairment

Age differences in the neural correlates underlying control of emotional memory: An event-related potential study

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.

Objective To investigate older and younger adults’ perceptions of older and younger adults who wear hearing aids. Design Participants completed two Implicit Association Tests: One with images of older adults (OA-IAT) and one with images of younger adults (YA-IAT), either wearing or not wearing hearing aids. Participants also rated age, attractiveness, and intelligence of younger and older adults pictured with or without a hearing aid. Study sample Thirty older adults (M age = 70 years, SD = 4.38) and 30 younger adults (M age = 23 years, SD = 3.01) who reported not having hearing aids or a diagnosed hearing impairment. Results For both IATs, older and younger participants responded faster and more accurately when images of individuals wearing hearing aids were paired with negative words in comparison to positive words. Photo ratings did not vary in relation to the presence or absence of hearing aids for either age group. Conclusion Although the photo rating tasks indicate neutral explicit attitudes towards individuals who wear hearing aids, our interpretation of the IAT results indicates that younger and older adults may hold negative implicit attitudes towards both older and younger hearing aid users.

Prior research suggests that older adults are less likely than young adults to use effective learning strategies during intentional encoding. This functional magnetic resonance imaging (fMRI) study investigated whether training older adults to use semantic encoding strategies can increase their self-initiated use of these strategies and improve their recognition memory. The effects of training on older adults' brain activity during intentional encoding were also examined. Training increased older adults' self-initiated semantic encoding strategy use and eliminated pretraining age differences in recognition memory following intentional encoding. Training also increased older adults' brain activity in the medial superior frontal gyrus, right precentral gyrus, and left caudate during intentional encoding. In addition, older adults' training-related changes in recognition memory were strongly correlated with training-related changes in brain activity in prefrontal and left lateral temporal regions associated with semantic processing and self-initiated verbal encoding strategy use in young adults. These neuroimaging results demonstrate that semantic encoding strategy training can alter older adults' brain activity patterns during intentional encoding and suggest that young and older adults may use the same network of brain regions to support self-initiated use of verbal encoding strategies.

BackgroundCognitive decline is prevalent among older adults and may be associated with their daily activity behaviours. However, no studies have examined how cognitive decline affects older adults’ activity behaviours within a 24-h framework. This study investigates the relationship between cognitive function and 24-h activity behaviours in older adults, further exploring whether these associations differ by sex.MethodThis study analyses data from the eighth wave of the Survey of Health, Ageing and Retirement in Europe, conducting a cross-sectional analysis of 814 older adults. Cognitive function was assessed using the SHARE-Cog tool, encompassing 10-word immediate recall, 10-word delayed recall, verbal fluency, and self-reported memory. 24-h activity behaviours (moderate-to-vigorous physical activity [MVPA], light physical activity [LPA], sedentary behaviour [SB], and sleep) were objectively measured with thigh-worn accelerometers. Compositional multivariate linear regression models were constructed using compositional data as the response variable, with cognitive function measures as predictors.ResultsHigher MVPA was linked to better cognitive outcomes (verbal fluency, 10-word immediate recall, and 10-word delayed recall) while SB and longer sleep related to poorer performance, with these associations being stronger in women (model p ≤ 0.001). Among women, cognitive outcomes were significantly associated with all activity behaviours (p range = 0.010–0.045). Women who self-reported poor memory and scored 0 on the verbal fluency spent approximately 45% of their day in SB, whereas those reporting excellent memory and scoring 60 spent 40.06% (37.18%, 42.86%) and 36.41% (31.53%, 41.10%) of their day sedentary, respectively. In contrast, men’s 24-h activity composition did not vary significantly with cognitive function (p range = 0.051–0.845).ConclusionOlder adults with better cognitive function tend to engage in more PA and reduce sedentary and sleep time. This relationship differed by sex, with females’ activity behaviours being more sensitive to cognitive function changes.ImplicationsThese findings suggest that interventions promoting healthy lifestyles in older adults should account for cognitive function, particularly in females.