USING VR FOR NAVIGATION ASSESSMENT IN OLDER ADULTS

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.

To investigate the association between pain and functional independence in older adults during and after admission to rehabilitation after an acute illness or injury. Prospective, observational cohort study. One community and one Veterans Affairs rehabilitation center. Individuals aged 65 and older admitted for rehabilitation after an acute illness or injury (postacute rehabilitation) (N = 245; mean age 80.6, 72% male)). Pain was assessed using the Geriatric Pain Measure (GPM, score 0-100). Functional independence was measured using the motor component of the Functional Independence Measure (mFIM, score 13-91). Both scores were obtained at admission; discharge; and 3-, 6-, and 9-month follow-up. In bivariate analyses, discharge GPM and persistent pain (lasting >3 months) were evaluated as predictors of mFIM score at 9 months. Applying a multilevel modeling (MLM) approach, individual deviations in GPM scores were used to predict variations in mFIM. At admission, 210 participants (87.9%) reported pain (16.3% mild (GPM<30); 49.3% moderate (GPM: 30-69); 22.1% severe (GPM>70)); 21.3% reported persistent pain after discharge. The bivariate analyses did not find statistically significant associations between discharge GPM or persistent pain and mFIM score at 9 months, but in the MLM analysis, deviations in GPM were significant predictors of deviations in mFIM score, suggesting that, when individuals experienced above-average levels of pain (GPM > their personal mean GPM), they also experienced worse functional independence (mFIM < their personal mean mFIM). Twenty-one percent of older adults undergoing postacute rehabilitation reported persistent pain after discharge from rehabilitation. The bivariate analysis did not find association between pain and functional independence, but MLM analysis showed that, when participants experienced more pain than their average, they had less functional independence.

The goal of this study was to examine the degree to which age-related differences in early or automatic levels of auditory processing and attention-related processes explain age-related differences in auditory temporal processing. We hypothesized that age-related differences in attention and cognition compound age-related differences at automatic levels of processing, contributing to the robust age effects observed during challenging listening tasks. We examined age-related and individual differences in cortical event-related potential (ERP) amplitudes and latencies, processing speed, and gap detection from 25 younger and 25 older adults with normal hearing. ERPs were elicited by brief silent periods (gaps) in an otherwise continuous broadband noise and were measured under two listening conditions, passive and active. During passive listening, participants ignored the stimulus and read quietly. During active listening, participants button pressed each time they detected a gap. Gap detection (percent detected) was calculated for each gap duration during active listening (3, 6, 9, 12, and 15 msec). Processing speed was assessed using the Purdue Pegboard Test and the Connections Test. Repeated measures analyses of variance assessed effects of age on gap detection, processing speed, and ERP amplitudes and latencies. An "attention modulation" construct was created using linear regression to examine the effects of attention while controlling for age-related differences in auditory processing. Pearson correlation analyses assessed the extent to which attention modulation, ERPs, and processing speed predicted behavioral gap detection. Older adults had significantly poorer gap detection and slower processing speed than younger adults. Even after adjusting for poorer gap detection, the neurophysiological response to gap onset was atypical in older adults with reduced P2 amplitudes and virtually absent N2 responses. Moreover, individual differences in attention modulation of P2 response latencies and N2 amplitudes predicted gap detection and processing speed in older adults. That is, older adults with P2 latencies that decreased and N2 amplitudes that increased with active listening had faster processing speed and better gap detection than those older adults whose P2 latencies increased and N2 amplitudes decreased with attention. The results from the present study are broadly consistent with previous findings that older adults exhibit significantly poorer gap detection than younger adults in challenging tasks. Even after adjusting for poorer gap detection, older and younger adults showed robust differences in their electrophysiological responses to sound offset. Furthermore, the degree to which attention modulated the ERP was associated with individual variation in measures of processing speed and gap detection. Taken together, these results suggest an age-related deficit in early or automatic levels of auditory temporal processing and that some older adults may be less able to compensate for declines in processing by attending to the stimulus. These results extend our previous findings and support the hypothesis that age-related differences in cognitive or attention-related processing, including processing speed, contribute to an age-related decrease in gap detection.

BackgroundThe ability to perform sit-to-stand (STS) transitions is a fundamental marker of functional independence in older adults, and age-related declines in STS performance are strongly linked to increased fall risk and compromised quality of life. While mind–body exercises like Tai Chi have shown promise in enhancing physical function in this population, the specific neuromuscular mechanisms through which Tai Chi improves STS performance—particularly how it modulates biomechanical patterns and muscle control during this critical movement—remain poorly understood.ObjectiveThis study aimed to investigate the effects of a 16-week, Yang-style Tai Chi programme on STS performance and lower limb neuromuscular control strategies underpinning any improvements in older adults. Methods: Sixty community-dwelling older adults (60–75 years) stratified by sex and baseline STS time. The 32 older adults were recruited as the experimental group (Tai Chi practitioners), and 28 as the control group (maintaining habitual lifestyle). The experimental group underwent 16 weeks of Tai Chi practice (5 sessions/week, 40 min/session), while the control group maintained their original daily routines. Before and after the intervention, the following parameters were measured during STS transitions: center of pressure (COP), temporal parameters, and surface electromyography (sEMG) signals of relevant lower limb muscles.ResultsData indicated that with increasing age, older adults exhibited decreased physical activity levels and impaired STS ability. After 16 weeks of Tai Chi practice, the experimental group showed significant improvements in STS ability, with marked reductions in reaction time, standing phase duration, and total time for Five Times Sit-to-Stand Test (FTSST). During STS tasks, the sample entropy of COP in the experimental group significantly decreased, accompanied by reduced sEMG amplitudes of the biceps femoris, rectus femoris, and tibialis anterior.ConclusionThis study demonstrated that aging is associated with declines in physical activity, reaction capacity, and STS ability in older adults. Tai Chi improves STS performance through greater neuromuscular efficiency and reduced postural sway, providing a mechanistic rationale for its integration into fall-prevention programs for older adults.

Age-related changes in slow wave activity rise time and NREM sleep EEG with and without zolpidem in healthy young and older adults

ABSTRACTAccording to current textbook knowledge, the primary somatosensory cortex (SI) supports unilateral tactile representations, whereas structures beyond SI, in particular the secondary somatosensory cortex (SII), support bilateral tactile representations. However, dexterous and well-coordinated bimanual motor tasks require early integration of bilateral tactile information. Sequential processing, first of unilateral and subsequently of bilateral sensory information, might not be sufficient to accomplish these tasks. This view of sequential processing in the somatosensory system might therefore be questioned, at least for demanding bimanual tasks. Evidence from the last 15 years is forcing a revision of this textbook notion. Studies in animals and humans indicate that SI is more than a simple relay for unilateral sensory information and, together with SII, contributes to the integration of somatosensory inputs from both sides of the body. Here, we review a series of recent works from our own and other laboratories in favour of interactions between tactile stimuli on the two sides of the body at early stages of processing. We focus on tactile processing, although a similar logic may also apply to other aspects of somatosensation. We begin by describing the basic anatomy and physiology of interhemispheric transfer, drawing on neurophysiological studies in animals and behavioural studies in humans that showed tactile interactions between body sides, both in healthy and in brain-damaged individuals. Then we describe the neural substrates of bilateral interactions in somatosensation as revealed by neurophysiological work in animals and neuroimaging studies in humans (i.e., functional magnetic resonance imaging, magnetoencephalography, and transcranial magnetic stimulation). Finally, we conclude with considerations on the dilemma of how efficiently integrating bilateral sensory information at early processing stages can coexist with more lateralized representations of somatosensory input, in the context of motor control.

Similarities exist in how people process and represent spatial information and in the factors that contribute to disorientation, whether one is moving through airspace, on the ground, or surgically within the body. As such, design principles for presenting spatial information should bear similarities across these domains but also be somewhat specific to each. In this chapter, we review research in spatial cognition and its application to navigation system design for within-vehicle, aviation, and endoscopic navigation systems. Taken together, the research suggests three general principles for navigation system design consideration. First, multimedia displays should present spatial information visually and action and description information verbally. Second, display organizations should meet users' dynamic navigational goals. Third, navigation systems should be adaptable to users' spatial information preferences. Designers of adaptive navigation display technologies can maximize the effectiveness of those technologies by appealing to the basic spatial cognition processes employed by all users while conforming to user's domain-specific requirements.

Everyday life unfolds in both space and time, with our spatial experiences playing a central role in our interactions with the world. To grasp human cognition, it s essential to understand how we perceive spatial relationships and tackle spatio-temporal challenges. Over the past few decades, research in spatial cognition has made significant strides, particularly in developing computational methods for knowledge representation and reasoning. This special issue explores various approaches to formalizing, implementing, and automating solutions for spatial problems. In this introduction, we provide a current literature review to contextualize the three contributions featured in this issue.

Navigation is essential to life, and it is cognitively complex, drawing on abilities such as prospective and situated planning, spatial memory, location recognition, and real-time decision-making. In many cases, day-to-day navigation is embedded in a social context where cognition and behavior are shaped by others, but the great majority of existing research in spatial cognition has focused on individuals. The two studies we report here contribute to our understanding of social wayfinding, assessing the performance of paired and individual navigators on a real-world wayfinding task in which they were instructed to minimize time and distance traveled. In the first study, we recruited 30 pairs of friends (familiar dyads); in the second, we recruited 30 solo participants (individuals). We compare the two studies to the results of an earlier study of 30 pairs of strangers (unfamiliar dyads). We draw out differences in performance with respect to spatial, social, and cognitive considerations. Of the three conditions, solo participants were least successful in reaching the destination accurately on their initial attempt. Friends traveled more efficiently than either strangers or individuals. Working with a partner also appeared to lend confidence to wayfinders: dyads of either familiarity type were more persistent than individuals in the navigation task, even after encountering challenges or making incorrect attempts. Route selection was additionally impacted by route complexity and unfamiliarity with the study area. Navigators explicitly used ease of remembering as a planning criterion, and the resulting differences in route complexity likely influenced success during enacted navigation.

This chapter discusses cognitive issues about the use of maps and spatial orientation in the environment and possible implications of research in the literature of spatial cognition for map and navigation learning in STEAM. It first clarifies the tradition of research in spatial cognition, behavior, and thinking and discusses the concept of spatial representation in relation to symbolic and geometric understanding of maps and the acquisition of spatial knowledge in the environment. Then the chapter looks at the difficulties that students have with maps in terms of projection, scaling, and symbolization and discusses the possibility of instructional intervention, taking the degree of iconicity of spatial representations and the alignment of maps with the surrounding environments into account. Concerning spatial orientation, cognitive demands that configurational learning in large-scale environments poses and the distortions typically observed in people’s spatial knowledge and judgments are discussed, in particular the theoretical and practical implications of the existence of large individual differences. Finally, the chapter explains the manners in which people identify and communicate their locations in the environment and considers problems and prospects of spatial awareness in the age of advanced geospatial information and technology.

The classical psychophysical approach to human perception has been to study isolated aspects of perception using well-controlled and strongly simplified laboratory stimuli. This so-called cue reduction technique has successfully led to the identification of numerous perceptual mechanisms, and has in many cases guided the uncoverage of neural correlates (see chapters elsewhere in this volume). Its limitations, however, lie in the almost complete ignorance of the intimate relationship among action, perception, and the environment in which we live. Real world situations are so different from the stimuli used in classical psychophysics and the context in which they are presented that applying laboratory results to daily life situations often becomes impractical, if not impossible. At the Max-PlanckInstitute for Biological Cybernetics in Tübingen, we pursue a behavioral approach to human action and perception that proves especially well-suited for studying more complex cognitive functions, such as object recognition and spatial cognition. The recent availability of high-fidelity “virtual reality” environments enables us to provide subjects a level of sensory realism and dynamic sensory feedback that approaches their experiences in the real world. At the same time, we can keep the ultimate control over all stimulus aspects that are required by the rules of psychophysics. In this chapter, we take a closer look at these developments in spatial cognition research and present results from several different experimental studies that we have conducted using this approach.

Tourette syndrome (TS) is a childhood-onset neurological disorder characterised by the occurrence of motor and vocal tics and the presence of premonitory sensory/urge phenomena. Functional neuroimaging studies in humans, and experimental investigations in animals, have shown that the genesis of tics in TS involve a complex interaction between cortical-striatal-thalamic-cortical brain circuits and additionally appears to involve the cerebellum. Furthermore, structural brain imaging studies have demonstrated alterations in grey matter (GM) volume in TS across a wide range of brain areas, including alterations in GM volume within the cerebellum. Until now, no study to our knowledge has yet investigated how GM structural covariance networks linked to the cerebellum may be altered in individuals with TS. In this study we employed voxel-based morphometry, and a ‘seed-to-voxel’ structural covariance network (SCN) mapping approach, to investigate alterations in GM cerebellar volume in people with TS, and alterations in cerebellar SCNs associated with TS. Data from 64 young participants was entered in the final analysis, of which 28 had TS while 36 were age-and sex-matched healthy volunteers. Using the spatially unbiased atlas template of the cerebellum and brainstem (SUIT) atlas, we found reduced GM volume in cerebellar lobule involved in higher-order cognitive functions and sensorimotor processing, in patients. In addition, we found that several areas located in frontal and cingulate cortices and sensorimotor network in addition to subcortical areas show altered structural covariance with our cerebellar seed compared to age-matched controls. These results add to the increasing evidence that cortico-basal ganglia–cerebellar interactions play an important role in tic symptomology.

We present a novel group-wise registration method for cortical correspondence for local cortical thickness analysis in human and non-human primate neuroimaging studies. The proposed method is based on our earlier template based registration that estimates a continuous, smooth deformation field via sulcal curve-constrained registration employing spherical harmonic decomposition of the deformation field. This pairwise registration though results in a well-known template selection bias, which we aim to overcome here via a group-wise approach. We propose the use of an unbiased ensemble entropy minimization following the use of the pairwise registration as an initialization. An individual deformation field is then iteratively updated onto the unbiased average. For the optimization, we use metrics specific for cortical correspondence though all of these are straightforwardly extendable to the generic setting: The first focused on optimizing the correspondence of automatically extracted sulcal landmarks and the second on that of sulcal depth property maps. We further propose a robust entropy metric and a hierarchical optimization by employing spherical harmonic basis orthogonality. We also provide the detailed methodological description of both our earlier work and the proposed method with a set of experiments on a population of human and non-human primate subjects. In the experiment, we have shown that our method achieves superior results on consistency through quantitative and visual comparisons as compared to the existing methods.

Although there is a large potential overlap between neuroscience and architecture, the studies bridging these fields are rare and newly emerging. Moreover, a gap is observed between the constructs, terminologies and research methods of architecture and neuroscience. In order to alleviate these problems, this study investigates main research themes and developments in spatial cognition research over the past two decades on the basis of the author keywords of published articles. Vosviewer© bibliometric analysis software was utilized to conduct keyword co-occurrence analysis, keyword clustering, and timeline analysis of keywords and current research on spatial cognition is discussed accordingly. The paper also reviews existing research at the intersection of neuroscience and architecture and comments on how this nexus could evolve in the future. It is concluded that embodied spatial cognition and affordances of architectural design provide a robust framework to guide further studies in this track.

Physical capacity (PC) is a strong determinant of health, quality of life, and functional independence in older adults. Having reference values for PC specific to a particular region allows for a contextual interpretation of an individual's level. The objectives of this study were to describe the evolution of key aspects of PC during the aging process and provide reference values for the major components of health-related PC for the older adult population in Northwest Mexico. A total of 550 independent older adults (60-84 years, 70% women) from the city of Hermosillo (Sonora, Mexico) were included between January and June 2019. PC was assessed using the Senior Fitness Test Battery (SFTB) and grip-strength test. Reference values were established for 5-year age groups, providing percentile values at 10, 25, 50, 75, and 90. The percentage decrease in functional capacity with aging was determined via a linear regression analysis of age against the percentage value of each subject relative to the average value of 60-year-old individuals of the same sex. Statistically significant differences in the results between men and women within the same age group were few and inconsistent, except for handgrip strength, which was lower in women across all age groups. The functional level, with respect to reference values for each age and sex group, was similar between men and women. The most pronounced functional decline during the aging period occurs between 70 and 80 years of age. The various tests generally show an annual percentage loss of approximately 1% from 60 years of age. This is the first study in Mexico that provides reference values for physical capacity using the Senior Fitness Test Battery. In general, older adults-both men and women-show similar functional levels with respect to their respective reference values. In general, an annual decline of 1% from the age of 60 years occurs.