Calibration of double stripe 3D laser scanner systems using planarity and orthogonality constraints

In this study, 3D scanning systems that utilize a pair of laser stripes are studied. Three types of scanning systems are implemented to scan environments, rough surfaces of near planar objects and small 3D objects. These scanners make use of double laser stripes to minimize the undesired effect of occlusions. Calibration of these scanning systems is crucially important for the alignment of 3D points which are reconstructed from different stripes. In this paper, the main focus is on the calibration problem, following a treatment on the pre-processing of stripe projections using dynamic programming and localization of 2D image points with sub-pixel accuracy. The 3D points corresponding to laser stripes are used in an optimization procedure that imposes geometrical constraints such as coplanarities and orthogonalities. It is shown that, calibration procedure proposed here, significantly improves the alignment of 3D points scanned using two laser stripes

Jigsaw Puzzling Taps Multiple Cognitive Abilities and Is a Potential Protective Factor for Cognitive Aging

Prevention of neurocognitive disorders is currently one of the greatest unmet medical challenges. The cognitive effects of solving jigsaw puzzles (JPs) have not been studied so far, despite its frequent use as a leisure activity in all age cohorts worldwide. This study aimed at closing this gap between a lack of science and a frequent real-world use by investigating the cognitive abilities recruited by JP as well as the cognitive benefits of lifetime and 30-day JP experience. A total of 100 cognitively healthy adults (≥50 years of age) were randomized to either a 30-day home-based JP intervention (≥1 h/day) plus four sessions of cognitive health counseling (JP group) or four sessions of cognitive health counseling only (counseling group). We measured global visuospatial cognition by averaging the scores of eight z-standardized visuospatial cognitive abilities (perception, constructional praxis, mental rotation, speed, flexibility, working memory, reasoning, and episodic memory). JP skill was assessed with an untrained 40 piece JP and lifetime JP experience with retrospective self-report. JP skill was associated with all assessed cognitive abilities (rs ≥ 0.45, ps < 0.001), and global visuospatial cognition (r = 0.80 [95% CI: 0.72–0.86], p < 0.001). Lifetime JP experience was associated with global visuospatial cognition, even after accounting for other risk and protective factors (β = 0.34 [95% CI: 0.18–0.50], p < 0.001). The JP group connected on average 3589 pieces in 49 h. Compared to the counseling group, they improved in JP skill (Cohen’s d = 0.38 [95% CI: 0.21–0.54], p < 0.001), but not in global visuospatial cognition (Cohen’s d = -0.08, [CI: -0.27 to 0.10], p = 0.39). The amount of jigsaw puzzling was related to changes in global visuospatial cognition within the JP group, only after accounting for baseline performance (β = 0.33 [95% CI: 0.02–0.63], p = 0.03). In sum, our results indicate that jigsaw puzzling strongly engages multiple cognitive abilities and long-term, but not short-term JP experiences could relevantly benefit cognition.Trial Registration:ClinicalTrials.govIdentifier: NCT0266731

Cognitive change is more positively associated with an active lifestyle than with training interventions in older adults at risk of dementia: a controlled interventional clinical trial

Background: While observational studies show that an active lifestyle including cognitive, physical, and social activities is associated with a reduced risk of cognitive decline and dementia, experimental evidence from corresponding training interventions is more inconsistent with less pronounced effects. The aim of this study was to evaluate and compare training- and lifestyle-related changes in cognition. This is the first study investigating these associations within the same time period and sample. Methods: Fifty-four older adults at risk of dementia were assigned to 10 weeks of physical training, cognitive training, or a matched wait-list control condition. Lifestyle was operationalized as the variety of self-reported cognitive, physical, and social activities before study participation. Cognitive performance was assessed with an extensive test battery prior to and after the intervention period as well as at a 3-month follow-up. Composite cognition measures were obtained by means of a principal component analysis. Training- and lifestyle-related changes in cognition were analyzed using linear mixed effects models. The strength of their association was compared with paired t-tests. Results: Neither training intervention improved global cognition in comparison to the control group (p = .08). In contrast, self-reported lifestyle was positively associated with benefits in global cognition (p < .001) and specifically in memory (p < .001). Moreover, the association of an active lifestyle with cognitive change was significantly stronger than the benefits of the training interventions with respect to global cognition (ps < .001) and memory (ps < .001). Conclusions: The associations of an active lifestyle with cognitive change over time in a dementia risk group were stronger than the effects of short-term, specific training interventions. An active lifestyle may differ from training interventions in dosage and variety of activities as well as intrinsic motivation and enjoyment. These factors might be crucial for designing novel interventions, which are more efficient than currently available training interventions

Quantitative analysis of regional distribution of tau pathology with 11C-PBB3-PET in a clinical setting.

PURPOSE The recent developments of tau-positron emission tomography (tau-PET) enable in vivo assessment of neuropathological tau aggregates. Among the tau-specific tracers, the application of 11C-pyridinyl-butadienyl-benzothiazole 3 (11C-PBB3) in PET shows high sensitivity to Alzheimer disease (AD)-related tau deposition. The current study investigates the regional tau load in patients within the AD continuum, biomarker-negative individuals (BN) and patients with suspected non-AD pathophysiology (SNAP) using 11C-PBB3-PET. MATERIALS AND METHODS A total of 23 memory clinic outpatients with recent decline of episodic memory were examined using 11C-PBB3-PET. Pittsburg compound B (11C-PIB) PET was available for 17, 18F-flurodeoxyglucose (18F-FDG) PET for 16, and cerebrospinal fluid (CSF) protein levels for 11 patients. CSF biomarkers were considered abnormal based on Aβ42 ( 450 ng/L). The PET biomarkers were classified as positive or negative using statistical parametric mapping (SPM) analysis and visual assessment. Using the amyloid/tau/neurodegeneration (A/T/N) scheme, patients were grouped as within the AD continuum, SNAP, and BN based on amyloid and neurodegeneration status. The 11C-PBB3 load detected by PET was compared among the groups using both atlas-based and voxel-wise analyses. RESULTS Seven patients were identified as within the AD continuum, 10 SNAP and 6 BN. In voxel-wise analysis, significantly higher 11C-PBB3 binding was observed in the AD continuum group compared to the BN patients in the cingulate gyrus, tempo-parieto-occipital junction and frontal lobe. Compared to the SNAP group, patients within the AD continuum had a considerably increased 11C-PBB3 uptake in the posterior cingulate cortex. There was no significant difference between SNAP and BN groups. The atlas-based analysis supported the outcome of the voxel-wise quantification analysis. CONCLUSION Our results suggest that 11C-PBB3-PET can effectively analyze regional tau load and has the potential to differentiate patients in the AD continuum group from the BN and SNAP group

Healthy cognitive aging through cognitive training, physical exercise, and leisure activities : from theory to new interventions

Neurocognitive health is becoming increasingly important in our aging population. Worldwide, around 47 million people are living with dementia and the number is expected to increase to 131.5 million by 2050. Engagement in a cognitively and physically demanding lifestyle over the lifespan is associated with healthy cognitive aging and a reduced risk of dementia in observational studies. However, translation of these findings into cognitive and physical interventions that effectively induce broad cognitive benefits was limited so far. Article 1 aimed to compare lifestyle- and intervention-related cognitive changes for the first time in the same sample and time period. Cognitive change was more positively associated with an active lifestyle than with traditional cognitive and physical training interventions, suggesting that the interventions did not fully implement the active ingredients (i.e., effective features) of an active lifestyle. Hence, theoretical, methodological, and empirical advances with respect to active ingredients are necessary for the development of more effective interventions. For this purpose, we proposed three theoretical frameworks that each derived one active ingredient: The overlapping variability framework suggested the combination of process-specific cognitive demands with high task variability as an effective feature (see Article 2); the guided plasticity facilitation framework proposed high temporal proximity of cognitive and physical demands as a decisive factor (see Articles 2 and 3); and the plasticity components framework assumed that the combination of process-specific cognitive demands with novel, educationally relevant information improves efficacy (see Article 4). In addition, we designed and assessed the effects of two intervention programs that implemented these frameworks: a card and board gaming intervention based on the overlapping variability framework (see Article 2) and a computerized, combined cognitive and physical training intervention based on the guided plasticity facilitation framework (see Article 3). We found evidence for broad cognitive benefits through both interventions in a pilot, randomized controlled trial (see Article 2) and in a large-scale, multi-center, controlled trial (see Article 3). In exploratory analyses of the combined cognitive and physical training intervention, we observed a trend for reduced cognitive benefits in participants with more severe neurocognitive disorders as well as a dose-response association between the number of training sessions and cognitive gains in individuals without dementia (see Article 3). To assess the plasticity components framework, Article 4 suggested that educational games are well suited for its implementation and proposed a research strategy to select and evaluate appropriate games. Next to the need for advances in intervention efficacy, the cognitive demands and benefits of frequently performed - but so far scientifically unexplored - leisure activities need to be revealed. Closing this science-practice gap is relevant as on the basis of dose-responsive effects not only efficacy but also amount of practice determines an activity's potential for cognitive benefits. Article 5 and 6 assessed the potential of jigsaw puzzling for healthy cognitive aging as an example of a frequently performed but so far unexplored leisure activity. The results indicated that jigsaw puzzling recruits multiple visuospatial cognitive abilities, e.g., working and episodic memory, reasoning, and cognitive flexibility. Additionally, the findings indicated that jigsaw puzzle experience over the lifespan is a new modifiable protective factor of cognitive aging, even though causality has not been clarified so far. The study provided no evidence that a 30-day jigsaw puzzle intervention improved cognition in a clinically relevant way. Finally, the neurobiological correlates of activity-related cognitive gains are relevant to pave the way for personalized treatments. However, knowledge in this area is still in its infancy, especially regarding the role of white matter integrity. Article 7 found no evidence that increases in white matter integrity is a neurobiological correlate of short-term activity-related cognitive changes in older adults at risk of dementia. However, a positive association between two training outcomes (cognitive training skill and functional physical fitness) and white matter integrity indicated a theoretical potential for training-related gains in white matter integrity. Taken together, the findings of Article 1 indicated a need for advances in intervention efficacy as the active ingredients of lifestyle-related cognitive changes may not be fully implemented in traditional training interventions. In Articles 2-4, theoretical, methodological, and empirical advances were provided regarding intervention efficacy by proposing three theoretical frameworks, designing two new interventions, providing evidence for their efficacy regarding gains in broad cognitive abilities, and suggesting cost-efficient research strategies for the selection of potentially beneficial activities in future trials. To clarify the unexplored potential of many frequently performed leisure activities for healthy cognitive aging, Article 5 and 6 revealed cognitive demands and effects of jigsaw puzzling as one example of these activities. Finally, Article 7 shed light on the role of white matter integrity as a potential neurobiological correlate of activity-related cognitive changes

Novelty Interventions to Enhance Broad Cognitive Abilities and Prevent Dementia : Synergistic Approaches for the Facilitation of Positive Plastic Change

Process-based cognitive trainings (PCTs) and novelty interventions are two traditional approaches aiming to prevent cognitive decline and dementia. However, both have their limitations. PCTs improve performance only in cognitive tests similar to the training tasks with inconsistent transfer effects on dissimilar tests. We argue that this learning specificity is due to a low training task variability. Novelty interventions are characterized by a high taskvariability but do not target specific processing demands affected in aging and dementia. To overcome the limitations of both approaches, we developed a process-based novelty intervention using a card and board game-based training approach. Here, we use highly variable tasks, which overlap in targeted processing demands (“overlapping variability” framework). Another nontraditional training approach combines cognitively with physically challenging tasksto induce multimechanistic effects, which might even interact positively. Initial results of both synergistic approaches indicate their potential to enhance broad cognitive abilities and prevent dementia

The TRACK-MS Test Battery: A Very Brief Tool to Track Multiple Sclerosis-Related Cognitive Impairment

Tracking cognition in patients with multiple sclerosis (MS) is important for detection of disease progression but it is often not performed in routine settings due to time constraints. This exploratory cohort study aims to develop a very brief repeatable tracking tool with comparable test quality criteria to the current gold standard, the Brief International Cognitive Assessment for MS (BICAMS). The study included 88 participants (22 healthy controls, 66 MS patients) who were examined at baseline and at one-year follow-up. As a validity criterion for the six administered cognitive tests, we assessed the difference between MS patients and HC, and the correlation with MS-related disability. Combining the two tests with the highest validity—the Controlled Oral Word Association Test and Symbol Digit Modalities Test—yielded an administration time of 5 min. Comparing this new TRACK-MS test battery with the 15 min BICAMS indicated that TRACK-MS showed larger differences between MS patients and healthy controls, a higher correlation with MS-related disability, smaller practice effects, and a good test–retest reliability. We provide evidence that TRACK-MS, although faster to administer, showed at least comparable quality criteria as the BICAMS. As the study was exploratory, replication of these results is necessary

Auditory Memory Decay as Reflected by a New Mismatch Negativity Score Is Associated with Episodic Memory in Older Adults at Risk of Dementia

The auditory mismatch negativity (MMN) is an event-related potential (ERP) peaking about 100–250 ms after the onset of a deviant tone in a sequence of identical (standard) tones. Depending on the interstimulus interval (ISI) between standard and deviant tones, the MMN is suitable to investigate the pre-attentive auditory discrimination ability (short ISIs, ≤ 2 s) as well as the pre-attentive auditory memory trace (long ISIs, &gt;2 s). However, current results regarding the MMN as an index for mild cognitive impairment (MCI) and dementia are mixed, especially after short ISIs: while the majority of studies report positive associations between the MMN and cognition, others fail to find such relationships. To elucidate these so far inconsistent results, we investigated the validity of the MMN as an index for cognitive impairment exploring the associations between different MMN indices and cognitive performance, more specifically with episodic memory performance which is among the most affected cognitive domains in the course of Alzheimer’s dementia (AD), at baseline and at a 5-year-follow-up. We assessed the amplitude of the MMN for short ISI (stimulus onset asynchrony, SOA = 0.05 s) and for long ISI (3 s) in a neuropsychologically well-characterized cohort of older adults at risk of dementia (subjective memory impairment, amnestic and non-amnestic MCI; n = 57). Furthermore, we created a novel difference score (ΔMMN), defined as the difference between MMNs to short and to long ISI, as a measure to assess the decay of the auditory memory trace, higher values indicating less decay. ΔMMN and MMN amplitude after long ISI, but not the MMN amplitude after short ISI, was associated with episodic memory at baseline (β = 0.38, p = 0.003; β = −0.27, p = 0.047, respectively). ΔMMN, but not the MMN for long ISIs, was positively associated with episodic memory performance at the 5-year-follow-up (β = 0.57, p = 0.013). The results suggest that the MMN after long ISI might be suitable as an indicator for the decline in episodic memory and indicate ΔMMN as a potential biomarker for memory impairment in older adults at risk of dementia

Effects of serotonergic psychedelics on mitochondria: Transdiagnostic implications for mitochondria-related pathologies

The use of serotonergic psychedelics has gained increasing attention in research, clinical practice and society. Growing evidence suggests fast-acting, transdiagnostic health benefits of these 5-hydroxytryptamine 2A receptor agonists. Here, we provide a brief overview of their benefits for psychological, cardiovascular, metabolic, neurodegenerative, and immunological pathologies. We then review their effect on mitochondria including mitochondrial biogenesis, functioning and transport. Mitochondrial dysregulation is a transdiagnostic mechanism that contributes to the aforementioned pathologies. Hence, we postulate that psychedelic-induced effects on mitochondria partially underlie their transdiagnostic benefits. Based on this assumption, we propose new treatment indications for psychedelics and that the health benefits induced by psychedelics depend on patient-specific mitochondrial dysregulation

No Evidence That Cognitive and Physical Activities Are Related to Changes in EEG Markers of Cognition in Older Adults at Risk of Dementia

An active lifestyle as well as cognitive and physical training (PT) may benefit cognition by increasing cognitive reserve, but the underlying neurobiological mechanisms of this reserve capacity are not well understood. To investigate these mechanisms of cognitive reserve, we focused on electrophysiological correlates of cognitive performance, namely on an event-related measure of auditory memory and on a measure of global coherence. Both measures have shown to be sensitive markers for cognition and might therefore be suitable to investigate potential training- and lifestyle-related changes. Here, we report on the results of an electrophysiological sub-study that correspond to previously published behavioral findings. Altogether, 65 older adults with subjective or objective cognitive impairment and aged 60-88 years were assigned to a 10-week cognitive (n = 19) or a 10-week PT (n = 21) or to a passive control group (n = 25). In addition, self-reported lifestyle was assessed at baseline. We did not find an effect of both training groups on electroencephalography (EEG) measures of auditory memory decay or global coherence (ps ≥ 0.29) and a more active lifestyle was not associated with improved global coherence (p = 0.38). Results suggest that a 10-week unimodal cognitive or PT and an active lifestyle in older adults at risk for dementia are not strongly related to improvements in electrophysiological correlates of cognition.publishe