Search

Funding Acknowledgements Type of funding sources: None. Background Bicuspid aortic valve (BAV) is the most common congenital cardiac condition among the general population and competitive athletes. BAV could be associated with progressive aortic dilatation, stenosis and/or regurgitation. There are concerns about the possible detrimental effects of exercise training on aortic size and valve function due to the hemodynamic stress on the aorta during exercise. However, data in the literature are scarce and sometimes discordant. Objectives This multicenter study aimed to analyze the influence of sport on aortic size and valve function in BAV patients. Methods Three groups were analyzed: competitive athletes with BAV, athletes with tricuspid aortic valve (TAV) and sedentary controls with BAV, age- and sex-matched. We assessed the morphology and degree of aortic valve stenosis, regurgitation, aortic dimension, and left ventricular (LV) characteristics by 2D echocardiography. Individuals with moderate-severe stenosis and regurgitation or relevant aortic dilation (> 45 mm (men) or >41 mm (women) were excluded from the study. Results The study population was composed of 500 subjects:184 BAV athletes (84% males; mean age 30±11 years), 191 TAV athletes (82% males; mean age 30±11 years), 125 BAV sedentary controls (82% males; mean age 34±10 years). The aortic annulus was greater in BAV athletes (25.0±3.6 mm) than in TAV athletes (21.7±2.9 mm) and BAV controls (23.9±3.6 mm), p Conclusions This multicenter study demonstrated that athletes with BAV have larger aortic diameters than athletes with TAV. However, no differences between BAV athletes and sedentary controls were observed, suggesting that exercise training does not significantly affect aortic dilation, with the exception of aortic annulus. Conversely, sports practice negatively influenced valve function in BAV athletes. Valvular dysfunction seems to affect the LV geometry, with a trend for being more dilated and hypertrophic in BAV athletes than in the other groups.

Funding Acknowledgements Type of funding sources: None. Background Despite the widespread use of wearables in endurance sports allowing the measurements needed for quantification of the training load (TL), studies in sports cardiology consistently use less reliable questionnaires to assess TL.[1] This scant use of activity trackers to determine TL can be explained by the large workload for data analysis. Purpose We aimed to develop a semi-automated post-processing tool that allows quantifying TL, based on heart rate (HR) monitoring by commercial wearables, for future use in clinical and epidemiological studies. We compared the calculated maximal HR automatically derived from HR monitoring during endurance training with the maximal HR obtained during incremental exercise testing in the lab. We describe TL calculated by our tool in young and older endurances athletes and compare it with the TL obtained via questionnaires. Methods Training data was collected in two multicenter studies. Master@Heart is a cohort study of endurance trained middle-aged men between 45 and 70 years.[2] Pro@Heart is a prospective study in young endurance athletes between 16 and 23 years.[3] For the purpose of this substudy, 44 athletes (38 ± 17 years) that had recorded all their training sessions using a chest-worn HR monitor for one year were included. Using an in-house developed pipeline in R (R core Team, Vienna, Austria), maximal HR and TL were calculated from training data. The maximal HR measured in the field (Tangent MaxHR) was then compared with the lab-measured maximal HR (Lab MaxHR). Both Lucia training impulse (LuTRIMP) and Edwards TRIMP (eTRIMP) were compared as measures of TL based on HR-based intensity zones. LuTRIMP, based on individually based exercise intensity zones, and eTRIMP based on the Tangent MaxHR. Participants filled in a standard exercise questionnaire to determine the amount of training sessions and training hours per week. Results Lab MaxHR was lower than Tangent MaxHR (183 ± 12.2bpm vs. 188.3 ± 13.0bpm; Figure 1 A), but correlated strongly (r=0.81, P Conclusion Our tool allows to semi-automatically quantify different TL parameters in endurance athletes from a wide age range. The use of questionnaires to determine TL is inaccurate. TL calculated using eTRIMP is comparable to TL calculated using LuTRIMP. Since eTRIMP does not require an exercise test, it is more easily implementable in large studies.

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWO - Research Foundation – Flanders. Background Exercise is a key therapy for patients across all the stages of heart failure with preserved ejection fraction (HFpEF). Despite being a class I recommendation, the EUROASPIRE registry showed that only a third of patients is sufficiently active, with numbers being even lower among patients with symptomatic HFpEF (stage C). Knowledge of barriers and confidence to exercise is needed to increase the uptake of exercise and a physically active lifestyle. Objective To assess barriers to exercise and self-efficacy in patients along the continuum of HFpEF and to detect possible differences between patients in different HFpEF stages. Methods The first 60 patients (n = 20 HFpEF stage A, 20 HFpEF stage B, 20 HFpEF stage C) from the PRIORITY randomized controlled trial (PeRsonalIzed remOtely guided preventive exeRcIse therapy for a healThY heart) were included. Barriers to exercise and self-efficacy were evaluated using the Exercise Barrier Questionnaire and the Exercise Self-Efficacy Scale. Results Patients with HFpEF stage C were older (72 ± 9.41 years), more likely to be female (70%) and were less physically fit (peak VO2 14.09 ± 2.58 ml/min/kg) compared to patients with HFpEF stage A (63.5 ± 9.10 years, 40% women and peak VO2 21.43 ± 4.94 ml/min/kg) and stage B (70.5 ± 5.25 years, 40% women and peak VO2 17.84 ± 5.15 ml/min/kg). As shown in Figure 1, patients with HFpEF stage C reported more barriers to exercise compared to patients with HFpEF stage A or HFpEF stage B. In particular, 50% of HFpEF stage C reported that they would not exercise when they perceived the exercise as boring (vs A:21%, B:22%), not fun (vs A: 21%, B:21%), if supervised by a bad instructor (vs A:32%, B:33%) or during holidays (vs A:26%, B:17%). Almost 40% of patients with HFpEF stage C reported that having to exercise alone would be a barrier for them (vs A:11%, B:22%). As shown in Figure 2, patients with HFpEF stage C were less confident that they 1) could overcome barriers to exercise by finding appropriate exercise resources (A:0%, B:6%, C:11%), 2) would exercise when feeling tired (A:5%, B:24%, C:28%), 3) would exercise without family support (A:5%, B:6%, C: 17%) or 4) without professional support (A:11%, B:18%, C:17%). Conclusion Barriers to exercise and self-efficacy were rated differently by the 3 stages of HFpEF. Patients with more advanced stages of HFpEF experienced more challenges to be physically active.

Funding Acknowledgements Type of funding sources: None. Introduction Radiomics of cardiac MRI T1, T2 and extracellular volume (ECV) maps has the potential to add biomarkers that can aid in the detection and diagnosis of myocardial diseases. Recently, the feasibility of CMR mapping based radiomics to classify various myocardial diseases was demonstrated [1-6]. However, reproducibility studies have reported sensitivity of radiomics to acquisition parameters and processing steps involved concluding that only a limited number of features may be reproducible [7-8]. As CMR mapping guidelines recommend to use site-specific normal values [9], radiomics features derived likely also need careful site-specific evaluation to benchmark disease-related feature alterations. Purpose We aimed to assess the between-session reproducibility of radiomics features in a longitudinal dataset of MOLLI T1 and ECV maps obtained in young athletes at 1.5T. Materials and methods This study included data from 17 healthy subjects (15-20y; informed consent obtained) with data acquired two years apart [10] considered for this purpose as test-retest data since a prior standard analysis showed near identical average T1 (t1: 977±16 ms, t2: 982±20ms) and ECV (t1: 23.4±1.3%, t2: 23.4±1.5%). T1 mapping data was acquired on a 1.5T system (Ingenia, Philips) using MOLLI 5s(3s)3s. After motion correction and T1 and ECV map calculation [11], the left ventricular myocardium was manually delineated by two readers independently (3D Slicer [12]). In total 44 images (short and long axis) were included for each time point. The radiomics analysis resulted in 96 features per image (7 feature families, ‘shape’ excluded; no filters applied; Pyradiomics, [13]). The concordance correlation coefficient (CCC) was calculated to assess reproducibility, and features with CCCs ≥ 0.7 were considered reproducible. A coefficient of variation (CV) below 15% was considered low. Results Only a limited number of radiomics features had high CCC (T1: 6/96 ECV 0/96) or a low CV (T1: 32/96, ECV:30/96) in the between-session analysis. The inter-reader evaluation showed that the effect of the delineation on the results was limited. Features that were most robust in the between-session analysis were ‘first order (total)energy’ for T1 maps and ‘glcm_Autocorrelation’ for ECV maps (table 1). These results in young healthy subjects confirm previous test-retest reports [9-10]. Features with low CCC levels or high CV may however still be useful when discriminating between patient with myocardial diseases if the difference is larger than the confidence interval assessed via this reproducibility analysis. Conclusion In these healthy subjects, a strong variability in reproducibility of radiomics features of T1 and ECV mapping can be noted. Nonetheless, these variability measures are informative to determine features that are likely most robust when discriminating between health and disease and can be used as a benchmark towards radiomics AI-based diagnostic approaches. Top ranked features for either T1 or ECV

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): research Foundation - Flanders (FWO) Introduction Cardiac dysfunction is highly prevalent in patients with type 2 diabetes mellitus (T2DM), leading to increased risk of cardiac morbidity and premature death. Previous research underscored the high prevalence of a disturbed global longitudinal strain (GLS), a marker to predict this cardiac dysfunction, in both symptomatic and asymptomatic T2DM patients. Exercise-based therapy is recommended in the management of patients with type 2 diabetes. However, it remains unclear i) which type of exercise therapy to have the biggest effect on GLS and ii) which factors modify the effect of exercise therapy on GLS. Purpose The PROTECTION study will i) investigate the impact of exercise volume and intensity on GLS to optimize exercise prescription in T2DM and will ii) assess which patient-specific factors influence the change in GLS and physical fitness as a result of exercise intervention in T2DM. Methods and analyses The PROTECTION study is composed of two work packages (WP). In WP 1, 100 T2DM adults (50% male, aged 30-75 years) will be randomized to a usual care group or one of the three supervised exercise intervention groups (see Table 1) for a duration of 26 weeks. Outcome measures will be performed at baseline, 13, 26 and 52 weeks of follow-up. The primary outcomes are GLS and cardiac dimensions. Secondary outcomes include health-related physical fitness, blood biomarkers and physical activity behavior. Data will be analyzed by two-way ANOVA repeated measures. A two-tailed P-value Parallel with the randomized controlled trial, a longitudinal intervention study (WP2) involving 107 adults (50% male, aged 30-75 years) with T2DM will be conducted. All participants will engage in a supervised intervention for 26 weeks, including a high volume of moderate intense physical activity (see Table 1). The main objective of this work package is to define determinants of change in GLS during an exercise intervention. Moreover, the interaction between diet-exercise, habitual physical activity-exercise and phenotype-exercise on change in GLS will be studied in great detail. Patient-specific data will be analyzed by multivariate regression analysis. A two-tailed P-value Conclusion It is anticipated that the PROTECTION study will contribute to a better understanding on i) which exercise characteristics are preferred to maximally improve GLS in T2DM and on ii) the determinants of the responsiveness of GLS and physical fitness to exercise in T2DM.

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research Foundation – Flanders (FWO) Introduction Approximately half of the heart failure population has heart failure with preserved ejection fraction (HFpEF), a chronic disease starting with cardiovascular risk factors such as hypertension, diabetes and obesity (stage A) which can further emerge in a structural heart disease without (stage B) or with (stage C) signs or symptoms. Structured exercise therapy is recommended as a Class IA intervention in national and international guidelines and, as such, should be offered to all patients. Yet, in current practice, exercise therapy is often only offered within a secondary prevention program. At present, there exists no comprehensive preventive care program that includes structured exercise for patients in the early stages of heart failure, when cardiovascular risk factors are present, but cardiac remodeling and dysfunction might still be reversible or even preventable. Purpose PRIORITY aims to investigate the use of remotely guided exercise therapy as a preventive clinical and cost-effective treatment in the HFpEF continuum. This includes both prevention of progression of asymptomatic diastolic dysfunction towards symptomatic HFpEF (= primary prevention) and delaying progression of symptomatic HFpEF (= secondary prevention). Methods A randomized controlled multicenter trial will be conducted in 450 patients (men and women, aged 35-80 years) with heart failure (n = 180 stage A, 180 stage B, 90 stage C). Participants are being recruited from 3 different hospitals and the general population during a 16-month period which started in September 2021. Patients will be randomized (1:1) to usual care or to the PRIORITY exercise intervention (i.e. a combination of supervised with remotely guided home-based training sessions). Training prescription is based on the EXPERT tool and includes person-tailored endurance and dynamic strength training. During one year, participants will receive 18 supervised exercise sessions supplemented with a structured progressive home-based exercise program. Outcomes will be assessed at baseline, 4 months, one and two-years. Primary outcome is the proportion of patients with a clinically relevant improvement in peak oxygen uptake at one-year. Secondary outcomes include vascular health, muscle metabolism, change in electrocardiographic parameters and physical fitness parameters (muscle strength, body composition). Further, big data of physical activity collected during the trial will be used to develop models using machine-learning algorithms which can predict physical activity uptake and changes in fitness to facilitate the creation of more personalized interventions and better tailored exercise prescription. Conclusion We anticipate that the PRIORITY study will contribute to better prevention of heart failure thanks to an early easily accessible person-tailored exercise intervention.

Navigation ability is particularly sensitive to aging. Evidence of aging patterns is largely restricted to comparing young adults and elderly and limited in the variety of navigation tasks used. Therefore, we designed a novel task battery to assess navigation ability in a very large, representative sample (N = 11,887, 8–100 years). The main aim was to measure navigation ability across the lifespan in a brief, yet comprehensive manner. Tasks included landmark knowledge, egocentric and allocentric location knowledge, and path knowledge for a route and survey perspective. Additionally, factors that potentially contribute to navigation ability were considered; gender, spatial experience and spatial anxiety. Increase in performance with age in children was found for allocentric location knowledge and for route-based path knowledge. Age related decline was found for all five tasks, each with clearly discernible aging patterns, substantiated the claim that each task distinctively contributes to the assessment of navigation ability. This study provides an in depth examination of navigation ability across dissociable functional domains and describes cognitive changes across the lifespan. The outcome supports the use of this task battery for brief assessment of navigation for experimental and clinical purposes.

Post-stroke navigation complaints are frequent (about 30%) and intervention is possible, but there is no assessment instrument to identify patients with navigation complaints. We therefore studied the clinical validity of the Wayfinding Questionnaire (WQ) in a cross-sectional study with 158 chronic stroke patients and 131 healthy controls. Patients with low (more navigation complaints) versus normal WQ scores were compared for demographics, stroke characteristics, emotional and cognitive complaints, and health-related quality of life (HRQoL). Actual navigation performance of 78 patients was assessed in a virtual reality setting. Effect sizes (d) were calculated. WQ responses (22 items) of stroke patients were compared with those of controls (discriminant validity). Results showed that patients with a low WQ score (n = 49, 32%) were more often women (p = 0.013) and less educated (p = 0.004), reported more cognitive complaints (d = 0.69), more emotional problems (d = 0.38 and 0.52), and lower HRQoL (d = 0.40 and 0.45) and, last but not least, performed worse on the navigation ability tasks (d = 0.23–0.80). Patients scored lower than controls on 21/22 WQ items, predominantly with small to medium effect sizes (d = 0.20–0.51). We conclude that the WQ is valid as a measure of navigation complaints in stroke patients, and thus strongly advocate its use in stroke care.

Background/Introduction: There is an increased incidence of atrial fibrillation (AF) in endurance athletes. We sought to evaluate the likely mechanistic basis for this phenomenon. Methods 36 endurance athletes in sinus rhythm, with a previous history of AF (ATH-AF) were compared to age and gender matched endurance athletes with no prior history of AF (ATH), non athletes with paroxysmal AF (NONATH-AF) and age and gender matched healthy controls (CONTROL). A detailed transthoracic echocardiogram was performed with all groups in sinus rhythm, with detailed left atrial (LA) and left ventricular (LV) measurements, including strain analysis. Results All athletes had increased LA and LV size when compared with healthy controls (Table 1). Non athletes with paroxysmal AF had increased LA size when compared with controls. However, indexed LA/LV ratio was preserved in athletes and similar to healthy individuals, whilst AF patients had significantly increased LA/LV ratio. Athletes with AF had higher e’ velocity and lower E/e’, whereas e’ was reduced and E/e’ elevated in non-athlete AF patients. Athletes had impaired LA reservoir and contractile strain, and reduced LV global longitudinal strain (GLS) compared with healthy controls. Conclusions Compared to healthy controls, athletes have reduced LA and LV strain, with preserved LV diastolic function and LA/LV ratio. In contrast, altered diastolic function with differential increase in LA volume was observed in AF patients. The increased risk of AF in athletes is likely mediated by different mechanistic processes other than an atrial myopathy consequent to diastolic dysfunction as observed in non-athletes with AF. Table 1. LA and LV parameters Parameter ATH-AF ATH NONATH-AF CONTROL P value LVEDV indexed (ml/m2) 84 ± 12 79 ± 14 57 ± 10 51 ± 13

Introduction Iodine-124 positron emission tomography/computed tomography (I-124 PET/CT) is increasingly being used in the absorbed dose estimation in the radioiodine treatment of differentiated thyroid cancer (DTC). However, the produced prompt gamma coincidences (PGCs) associated with the I-124 decay result in a bias in the absorbed dose estimation. The impact of a sinogram-based PGC correction approach on the absorbed dose estimation in I-124 PET/CT DTC imaging is investigated. Methods I-124 phantom and patient measurements were performed on a Siemens Biograph mCT PET/CT system. All images were reconstructed with (PGC(on)) and without PGC correction (PGC(off)). The phantom contained seven spheres (diameters: 6.6-37 mm). The spheres and background compartment were filled with a I-124 solution, resulting in a low (9.4 : 1) and a high sphere-to-background activity concentration ratio (750 : 1). Sphere recovery coefficient (RC) values were determined. In addition, the impact of PGC correction on measured lesion uptake and calculated lesion-absorbed dose was assessed for 66 lesions identified in 24 DTC patients. Results PGC correction systematically increased sphere RC values up to 71% for the smallest spheres. For the patient data, PGC correction significantly increased both the measured I-124 uptake (P

The aim of this study was to assess how people memorize spatial information of emotionally laden landmarks along a route and if the emotional value of the landmarks affects the way metric and configurational properties of the route itself are represented. Three groups of participants were asked to watch a movie of a virtual walk along a route. The route could contain positive, negative, or neutral landmarks. Afterwards, participants were asked to: (a) recognize the landmarks; (b) imagine to walk distances between landmarks; (c) indicate the position of the landmarks along the route; (d) judge the length of the route; (e) draw the route. Results showed that participants who watched the route with positive landmarks were more accurate in locating the landmarks along the route and drawing the route. On the other hand, participants in the negative condition judged the route as longer than participants in the other two conditions and were less accurate in mentally reproducing distances between landmarks. The data will be interpreted in the light of the "feelings-as-information theory" by Schwarz (2010) and the most recent evidence about the effect of emotions on spatial memory. In brief, the evidence collected in this study supports the idea that spatial cognition emerges from the interaction between an organism and contextual characteristics.

Het navigatievermogen heeft grote invloed op het leven van de mens. Toch krijgt deze functie binnen de klinische neuropsychologie nog maar weinig aandacht. Het onderzoek naar de neurocognitieve architectuur van het navigatievermogen heeft door de technische ontwikkelingen van de afgelopen 20 jaar echter een enorme ontwikkeling doorgemaakt. Er zijn twee invloedrijke theoretische modellen ontstaan: het egocentrisch-allocentrisch model, dat onderscheid maakt tussen twee fundamenteel verschillende ruimtelijke perspectieven waarmee een omgeving geleerd en opgeslagen kan worden en het landmark-route-survey (LRS) model, dat drie verschillende typen kennis beschrijft, die bij het navigeren een rol spelen. Om de complexiteit van het navigatievermogen beter te begrijpen, lijkt niet alleen integratie van deze modellen zeer wenselijk, er moeten ook gegevens uit de klinische literatuur bij worden betrokken. In een systematische analyse van neuropsychologische casusstudies zijn recentelijk drie typen navigatiestoornissen geidentificeerd, die zijn gerelateerd aan problemen met herkenningspunten, locaties en paden. Het onderscheid tussen deze typen navigatiestoornissen vormen een eerste aanzet tot integratie van het egocentrisch-allocentrisch en het LRS-model. Deze integratie is noodzakelijk voor een adequate beschrijving van het navigatievermogen vanuit meer fundamentele en klinische perspectieven.

While the hippocampus has been ascribed a prominent role in navigation ability, it is still a subject of debate whether it contributes to learning novel environments only or to remembering familiar environments as well. We attempt to shed light on this issue by reporting on a patient who developed complaints of severe difficulties with navigation after she underwent a right anteromesial temporal lobectomy. A standard neuropsychological assessment revealed only a visuospatial working memory deficit. Clear evidence for problems with novel environments were found on a virtual route learning test. Two real‐world tests were used to investigate her ability to recall familiar environments. The first test was based on the area she grew up in (and still visits regularly) and the second test concerned her current place of residence which she never visited prior to the surgery. While her landmark recognition in general was accurate, she showed notable difficulties with indicating their locations on a map and with giving accurate route descriptions between them for both real‐world environments. This pattern of findings suggests that the hippocampus is not only important for navigation in novel environments, but also for familiar environments learned long ago.

Cardiac magnetic resonance imaging (CMR) has become an extremely valuable tool in the detection of cardiac pathology because of its accuracy in assessing cardiac structure and function, and its ability to provide tissue characterization. In this chapter we discuss the role of CMR in the evaluation of athletes, in whom it can be challenging to differentiate physiological changes from underlying myocardial pathology. It is fundamental to distinguish athletes undergoing CMR because of concerning symptoms from athletes evaluated for screening purposes with little pre-test probability for disease. We will briefly highlight state-of-the-art imaging sequences and post-processing techniques that are being used to assess cardiac morphology, function, and viability in athletes. Finally, we will discuss CMR findings present in inherited and acquired cardiomyopathies and how to distinguish these from physiological changes observed in highly trained athletes.

OBJECTIVE The notion of distinguishable processing mechanisms for spatial and spatiotemporal information has largely been neglected in the context of navigation. Only a recent neuropsychological case study has provided initial evidence for the idea that these elements can be differentiated at a functional level. The aim of the current study was therefore to critically verify this double dissociation by adopting a systematic, large-scale approach. METHOD Sixty-five chronic stroke patients and 60 matched healthy controls watched a route through a realistic virtual environment. They were assessed on their knowledge of this route in 4 different tasks after the learning phase. Performance on the scene recognition and route continuation tasks was taken as an indication of knowledge of the spatial route aspects. By contrast, spatiotemporal knowledge of the route was assessed in the route order and route progression tasks. RESULTS Based on single case statistics, 6 patients showed an exceptionally large difference in their performance on the spatial and spatiotemporal tasks. Moreover, 2 patients satisfied formal criteria for a classical dissociation. CONCLUSIONS Our findings showed that spatial and spatiotemporal performance was closely associated in most patients. Nonetheless, the study also provided partial support for the notion of separate space- and time-based processing mechanisms in the context of navigation. This distinction is of particular relevance to the investigation into the cognitive structure underlying navigation behavior. (PsycINFO Database Record

Aging effects have often been reported for spatial navigation performance. Moreover, navigation performance is thought to be an early marker of pathological aging. Yet, the cognitive complexity of navigation and large individual variation in healthy population make it difficult to pinpoint the precise aging mechanisms involved. We performed a systematic literature review with specific attention to functional dissociation between the tasks used and methodological characteristics. The literature search resulted in 39 articles in which age comparisons were made for large-scale navigation measures. Outcomes were categorized into the domains of landmark, location (egocentric and allocentric), and path knowledge (route and survey). Results indicate that clear functional dissociation exists between these navigation knowledge domains. Aging effects are found for path knowledge most convincingly, while landmark and egocentric location knowledge are frequently omitted in assessment. The participant samples reported often neglect adult, middle aged participants, while this group could be highly informative to the aging process as well. Moreover, having a clear image of age-related performance across the lifespan could be a valuable addition towards the early detection of pathological aging through navigation performance.

Objective: Landmark agnosia is a rare type of navigation impairment, for which various definitions have been presented. From a clinical as well as theoretical perspective, consensus on the characteristics of landmark agnosia would be valuable. In the current study we review the literature concerning landmark agnosia and present a new case study. Existing literature highlights the importance of examining familiar as well as novel landmark processing and substantial variation in performance patterns of individual patients.Method: We performed a case study with patient KS, a 53-year-old male, suffering from landmark agnosia, making use of elaborate neuropsychological screening and virtual reality-based tests of navigation ability.Results: Our extensive examination of his impairment shows that landmark agnosia can be very narrow; in KS it is restricted to recognition of newly learned landmarks only. Also, he has no trouble recognizing familiar landmarks that are not part of a navigated route.Conclusions: The literature review shows that the right temporal lobe, and the right hippocampus in particular are the main lesion sites for landmark agnosia. Furthermore, our case study substantiates that this disorder can occur for both familiar and novel landmarks, and can affect novel landmarks in isolation from familiar landmarks. Moreover, it can occur in isolation from problems with processing route information.

The neurocognitive architecture of navigation ability has been investigated by extensively studying the navigation problems of individual neurological patients. These neuropsychological case reports have applied highly variable approaches to establish navigation impairment in their patients. This review provides a systematic and up-to-date inventory of all relevant case studies and presents an analysis of the types of navigation impairments that have been described. The systematic literature search revealed 58 relevant papers reporting on 67 neurological patients. Close analysis of their patterns of navigation performance suggests three main categories of navigation impairments. These categories are related to three types of representations that are considered highly relevant for accurate navigation: knowledge of landmarks, locations, and paths. The resulting model is intended to serve both clinical and theoretical advances in the study of navigation ability and its neural correlates.

This paper presents a broadband, RF backscatter-based sensing method to identify the presence of payment terminal tampering, particularly using small, unwanted electronics such as payment skimmers in close proximity to a 5.8 GHz RFID tag. The broadband nature of this methodology makes it resilient to false alarms from interfering RF signals. Consistent detection of a conductive object is achieved by tracking long term changes in both magnitude and phase of the backscattered signal. In laboratory measurements, the presence of thin metal wires was determined for distances up to two wavelengths from the tag.

Recent studies have shown that navigation impairment is a common complaint after brain injury. Effective training programmes aiming to improve navigation ability in neurological patients are, however, scarce. The few reported programmes are merely focused on recalling specific routes rather than encouraging brain-damaged patients to use an alternative navigation strategy, applicable to any route. Our aim was therefore to investigate the feasibility of a (virtual reality) navigation training as a tool to instruct chronic stroke patients to adopt an alternative navigation strategy. Navigation ability was systematically assessed before the training. The training approach was then determined based on the individual pattern of navigation deficits of each patient. The use of virtual reality in the navigation strategy training in six middle-aged stroke patients was found to be highly feasible. Furthermore, five patients learned to (partially) apply an alternative navigation strategy in the virtual environment, suggesting that navigation strategies are mouldable rather than static. In the evaluation of their training experiences, the patients judged the training as valuable and proposed some suggestions for further improvement. The notion that the navigation strategy people use can be influenced after a short training procedure is a novel finding and initiates a direction for future studies.