Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study

BACKGROUND: Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles' distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians' behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions. METHODS: This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests. RESULTS: The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross. CONCLUSIONS: The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure. Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians' safety, in terms of speed limits, road design, and mixed physical-cognitive trainings.

β2-microglobulin is a systemic pro-aging factor that impairs cognitive function and neurogenesis

Aging drives cognitive and regenerative impairments in the adult brain, increasing susceptibility to neurodegenerative disorders in healthy individuals. Experiments using heterochronic parabiosis, in which the circulatory systems of young and old animals are joined, indicate that circulating pro-aging factors in old blood drive aging phenotypes in the brain. Here we identify β2-microglobulin (B2M), a component of major histocompatibility complex class 1 (MHC I) molecules, as a circulating factor that negatively regulates cognitive and regenerative function in the adult hippocampus in an age-dependent manner. B2M is elevated in the blood of aging humans and mice, and it is increased within the hippocampus of aged mice and young heterochronic parabionts. Exogenous B2M injected systemically, or locally in the hippocampus, impairs hippocampal-dependent cognitive function and neurogenesis in young mice. The negative effects of B2M and heterochronic parabiosis are, in part, mitigated in the hippocampus of young transporter associated with antigen processing 1 (Tap1)-deficient mice with reduced cell surface expression of MHC I. The absence of endogenous B2M expression abrogates age-related cognitive decline and enhances neurogenesis in aged mice. Our data indicate that systemic B2M accumulation in aging blood promotes age-related cognitive dysfunction and impairs neurogenesis, in part via MHC I, suggesting that B2M may be targeted therapeutically in old age.

The nociceptive withdrawal reflex: Normative values of thresholds and reflex receptive fields

Assessments of spinal nociceptive withdrawal reflexes can be used in human research both to evaluate the effect of analgesics and explore pain mechanisms related to sensitization. Before the reflex can be used as a clinical tool, normative values need to be determined in large scale studies. The aim of this study was to determine the reference values of spinal nociceptive reflexes and subjective pain thresholds (to single and repeated stimulation), and of the area of the reflex receptive fields (RRF) in 300 pain-free volunteers. The influences of gender, age, height, weight, body-mass index (BMI), body side of testing, depression, anxiety, catastrophizing and parameters of Short-Form 36 (SF-36) were analyzed by multiple regressions. The 95% confidence intervals were determined for all the tests as normative values. Age had a statistically and quantitatively significant impact on the subjective pain threshold to single stimuli. The reflex threshold to single stimulus was lower on the dominant compared to the non-dominant side. Depression had a negative impact on the subjective pain threshold to single stimuli. All the other analyses either did not reveal statistical significance or displayed quantitatively insignificant correlations. In conclusion, normative values of parameters related to the spinal nociceptive reflex were determined. This allows their clinical application for assessing central hyperexcitability in individual patients. The parameters investigated explore different aspects of sensitization processes that are largely independent of demographic characteristics, cognitive and affective factors.

Assessment of pain in sedated and mechanically ventilated patients: an observational study

Critically ill patients often undergo unpleasant procedures. We quantified the effects of an unpleasant stimulus on physiological and behavioral parameters and evaluated how they are modified by sedation and analgesia.

Clinical assessment of deficits after SAH: hasty neurosurgeons and accurate neurologists

For survivors of aneurysmal subarachnoid hemorrhage (SAH), somatic and cognitive deficits can affect long-term outcomes. We were interested in comparing the deficits identified in SAH patients, including cognitive deficits, at discharge by neurosurgeons and deficits identified by neurologists upon admission to the rehabilitation unit on the same day. The assessment of deficits might have an impact on referring patients to rehabilitation. This retrospective study included 494 SAH patients treated between 2005 and 2010. Of these, 50 patients were discharged to an affiliated rehabilitation unit. Deficits were grouped into 18 categories and summarized into three groups: major somatic, minor somatic, and cognitive deficits. Major somatic deficits were identified in 16 and 20 patients (p = 0.53), minor somatic deficits in 16 and 44 (p < 0.0001) patients, and cognitive deficits in 36 and 45 (p < 0.04) patients by neurosurgeons and neurologists, respectively. The absolute number of deficits in daily activities identified by the neurosurgeon and neurologist were 21 and 31 major somatic deficits (p = 0.2), 18 and 97 minor somatic deficits (p < 0.0001), and 61 and 147 cognitive deficits (p < 0.0001), respectively. Significant differences in assessment of cognitive and minor somatic deficits between neurosurgeons and neurologists exist. Based on these findings, it is evident that for the neurosurgeon, there needs to be an increased awareness of the assessment of cognitive deficits and a more routine interdisciplinary approach, including the use of neuropsychological evaluations, to ensure a better triage of patients to rehabilitation or for discharge home.

Structural and resting state functional connectivity of the subthalamic nucleus: identification of motor STN parts and the hyperdirect pathway

Deep brain stimulation (DBS) for Parkinson's disease often alleviates the motor symptoms, but causes cognitive and emotional side effects in a substantial number of cases. Identification of the motor part of the subthalamic nucleus (STN) as part of the presurgical workup could minimize these adverse effects. In this study, we assessed the STN's connectivity to motor, associative, and limbic brain areas, based on structural and functional connectivity analysis of volunteer data. For the structural connectivity, we used streamline counts derived from HARDI fiber tracking. The resulting tracks supported the existence of the so-called "hyperdirect" pathway in humans. Furthermore, we determined the connectivity of each STN voxel with the motor cortical areas. Functional connectivity was calculated based on functional MRI, as the correlation of the signal within a given brain voxel with the signal in the STN. Also, the signal per STN voxel was explained in terms of the correlation with motor or limbic brain seed ROI areas. Both right and left STN ROIs appeared to be structurally and functionally connected to brain areas that are part of the motor, associative, and limbic circuit. Furthermore, this study enabled us to assess the level of segregation of the STN motor part, which is relevant for the planning of STN DBS procedures.

Tracking the implicit self using event-related potentials

Negative biases in implicit self-evaluation are thought to be detrimental to subjective well-being and have been linked to various psychological disorders, including depression. An understanding of the neural processes underlying implicit self-evaluation in healthy subjects could provide a basis for the investigation of negative biases in depressed patients, the development of differential psychotherapeutic interventions, and the estimation of relapse risk in remitted patients. We thus studied the brain processes linked to implicit self-evaluation in 25 healthy subjects using event-related potential (ERP) recording during a self-relevant Implicit Association Test (sIAT). Consistent with a positive implicit self-evaluation in healthy subjects, they responded significantly faster to the congruent (self-positive mapping) than to the incongruent sIAT condition (self-negative mapping). Our main finding was a topographical ERP difference in a time window between 600 and 700 ms, whereas no significant differences between congruent and incongruent conditions were observed in earlier time windows. This suggests that biases in implicit self-evaluation are reflected only indirectly, in the additional recruitment of control processes needed to override the positive implicit self-evaluation of healthy subjects in the incongruent sIAT condition. Brain activations linked to these control processes can thus serve as an indirect measure for estimating biases in implicit self-evaluation. The sIAT paradigm, combined with ERP, could therefore permit the tracking of the neural processes underlying implicit self-evaluation in depressed patients during psychotherapy.

Patients with mild traumatic brain injury: immediate and long-term outcome compared to intra-cranial injuries on CT scan

BACKGROUND: Mild traumatic brain injury (MTBI) defined as Glasgow Coma Scale (GCS) 14 or 15 has shown contradictory short- and long-term outcomes. The objective of this study was to correlate intra-cranial injuries (ICI) on CT scan to neurocognitive tests at admission and to complaints after 1 year. METHODS: Two hundred and five patients with MTBI underwent a CT scan and were examined with neurocognitive tests. After 1 year complaints were assessed by phone interviews. RESULTS: The neurocognitive tests in 51% of the patients showed significant deficits; there was no difference for patients with GCS 14-15, nor was there a difference between patients with ICI to patients without. After 1 year patients with ICI had significantly more complaints than patients without ICI, the most frequent complaint was headache and memory deficits. CONCLUSIONS: No correlation was found between GCS or ICI and the neurocognitive tests upon admission. After 1 year, patients with ICI have significantly more complaints than patients without ICI. No cost savings resulted by doing immediate CT scan on all.

[Evaluation of the "Schema-focused Emotive Behavioural Therapy" (SET) for Patients with Personality Disorders: Results of a Randomised Controlled Trial.]

The "Schema-focussed Emotive Behavioral Therapy" (SET) was developed by our research group as a new group therapy approach for patients with personality disorders from all clusters (A to C; DSM-IV). It was evaluated in a randomised controlled study (n = 93). Data were collected before and after treatment as well as one year after study entry. A completer analysis was conducted with matched subgroups (n = 60). After therapy, SET patients improved in the outcome domains interactional behavior, strain, and symptomatic complaints (IIP-D, GAF, VEV-VW, BSI-P). Furthermore, they showed a significant lower dropout rate. At the follow-up assessment, Cluster C patients of the experimental group deteriorated with regard to symptomatic complaints (BSI-P). In contrast, cluster B patients improved more over time compared to control subjects. SET seems to be an adequate and effective group therapy with effects that seem to be stable over time, especially for patients with Cluster B diagnosis.

[Survival, clinical data and quality of life 10 years after heart transplantation: a prospective study]

AIM: To study prospectively patients after heart transplantation with respect to quality of life, mortality, morbidity, and clinical parameters before and up to 10 years after the operation. METHODS: Sixty patients (47.9 +/- 10.9 years, 57 men, 3 women) were transplanted at the University of Vienna Hospital, Department for Heart and Thorax Surgery and were included in this study. They were assessed when set on the waiting list, then exactly one, 5 and 10 years after the transplantation. The variables evaluated included physical and emotional complaints, well-being, mortality and morbidity. In the sample of patients who survived 10 years (n = 23), morbidity (infections, malignancies, graft arteriosclerosis, and rejection episodes) as well as quality of life were evaluated. RESULTS: Actuarial survival rates were 83.3, 66.7, 48.3% at 1, 5, and 10 years after transplantation, respectively. During the first year, infections were the most important reasons for premature death. As a cause of mortality, malignancies were found between years 1 and 5, and graft arteriosclerosis between years 5 and 10. Physical complaints diminished significantly after the operation, but grew significantly during the period from 5 to 10 years (p < 0.001). However, trembling (p < 0.05) and paraesthesies (p < 0.01) diminished continuously. Emotional complaints such as depression and dysphoria (both p < 0.05) increased until the tenth year after their nadir at year 1. In long-time survivors, 3 malignancies (lung, skin, thyroidea) were diagnosed 6 to 9 years postoperatively. Three patients (13%) had signs of graft arteriosclerosis at year 10; 9 (40%) patients suffered from rejection episodes during the course of 10 years. There were no serious rejection episodes deserving immediate therapy. Quality of life at 10 years is good in these patients. CONCLUSIONS: Heart transplantation is a successful therapy for patients with terminal heart disease. Long-term survivors feel well after 10 years and report a good quality of life.

[Physical and psychological status of 60-70-year-old citizens of Bern with neurotic symptoms in childhood--a study over more than 50 years (Emmental cohort)]

The present study was undertaken to assess the influence of childhood variables (physical and emotional) to later well-being in a group of rural Swiss (Emmental Cohort). Our study is the first prospective cohort over a time period of more than 50 years. It includes 1537 children who were listed and assessed in 1942 (T1) because they had difficulties in school or were otherwise behaviorally disturbed. In 1995 (T2) more than 60% of the initial population could be reassessed by our study group. We found more subjects at T2 who had been rated as intelligent at T1. More subjects responding to T2 belonged to a higher social class, were more anxious, and had more psychosocial problems at T1. Social income at T2 is correlated to the social class at T1. More subjects have died since who were rated at T1 as being less intelligent, less neurotical, and having higher psychosocial problems. Twice as many men died than women. The emotional situation at T2 is significantly correlated to psychological well-being at T1. The somatic complaints at T2 correlate significantly to neurotic symptoms in childhood (T1). The more intelligent the children were rated at T1, the less emotional and somatic complaints were voiced at T2 and the better the psychic well-being was rated (T2). In addition, the former social milieu (T1) significantly determined somatic and psychological complaints at T2. Our data discern a significant correlation between actual status and former childhood variables more than 50 years later in a rural Swiss cohort (Emmental Cohort).

Long-term effects of heart transplantation: the gap between physical performance and emotional well-being

The purpose of our study was to assess physical and emotional factors in heart transplant patients. A prospective design was used to compare patients' physical symptoms, emotional complaints, and restrictions at admission to the waiting list, immediately after, and 1 and 5 years after heart transplantation. Thirty-three patients were included (30 male, 3 female) in the study. Their mean age at admission was 48 +/- 10.2 years. Of these, 23 suffered from cardiomyopathy, 8 from coronary heart disease, and 2 from valvular insufficiency. At admission, the patients suffered from symptoms of cardiac insufficiency, and were restricted in sports, gardening, hobbies, sexual life, job, food-intake, and mobility. More than three-fourths rated their physical and emotional status as moderate to poor. Emotionally, they suffered from irritability, restlessness, depression, psychic lability, lowered drive, lack of social contact, low self-esteem, and anxiety. At the end of rehabilitation (4-8 weeks after the operation), all physical and emotional complaints, as well as restrictions had significantly decreased (p < 0.0001 to p < 0.001), except for trembling, numbness of hands/feet, and food-intake. One year postoperatively, patients reported even fewer physical complaints (p < 0.01). Three-fourths rated their physical and emotional status good or excellent. Five years postoperatively--in contrast to physical status, restrictions, and physical complaints--the emotional complaints had increased significantly (p < 0.0001). Patients reported excellent physical performance up to 5 years postoperatively. On the other hand, the study revealed that their emotional well-being had significantly deteriorated from 1 to 5 years postoperatively. Attention should, therefore, not only be paid to the good physical health of the survivors, but also to the worsening of their emotional status.

Clinical presentation of celiac disease and the diagnostic accuracy of serologic markers in children

There has been growing recognition of a changing clinical presentation of celiac disease (CD), with the manifestation of milder symptoms. Serologic testing is widely used to screen patients with suspected CD and populations at risk. The aim of this retrospective analysis was to evaluate the clinical presentation of CD in childhood, assess the diagnostic value of serologic tests, and investigate the impact of IgA deficiency on diagnostic accuracy. We evaluated 206 consecutive children with suspected CD on the basis of clinical symptoms and positive serology results. Ninety-four (46%) had biopsy-proven CD. The median age at diagnosis of CD was 6.8 years; 15% of the children were <2 years of age. There was a higher incidence of CD in girls (p = 0.003). Iron deficiency and intestinal complaints were more frequent in children with CD than those without CD (61% vs. 33%, p = 0.0001 and 71% vs. 55%, p = 0.02, respectively), while failure to thrive was less common (35% vs. 53%, p = 0.02). The sensitivity of IgA tissue transglutaminase (IgA-tTG) was 0.98 when including all children and 1.00 after excluding children with selective IgA deficiency. The specificity of IgA-tTG was 0.73 using the recommended cut-off value of 20 IU, and this improved to 0.94 when using a higher cut-off value of 100 IU. All children with CD and relative IgA deficiency (IgA levels that are measurable but below the age reference [n = 8]) had elevated IgA-tTG. In conclusion, CD is frequently diagnosed in school-age children with relatively mild symptoms. The absence of intestinal symptoms does not preclude the diagnosis of CD; many children with CD do not report intestinal symptoms. While the sensitivity of IgA-tTG is excellent, its specificity is insufficient for the diagnostic confirmation of a disease requiring life-long dietary restrictions. Children with negative IgA-tTG and decreased but measurable IgA values are unlikely to have CD.

Behavioral dominance between female color morphs of a Lake Victoria cichlid fish

Species that exhibit genetic color polymorphism are suitable for studying the evolutionary forces that maintain heritable phenotypic variation in nature. Male color morphs often differ in behavioral dominance, affecting the evolution of color polymorphisms. However, behavioral dominance among female color morphs has received far less attention. We studied a polymorphic population of the cichlid fish Neochromis omnicaeruleus from Lake Victoria, in which 3 distinct female color morphs coexist, black-and-white blotched (WB), orange blotched (OB), and plain (P) color morphs. First, we investigated dominance relationships among female morphs using triadic and dyadic encounters in the laboratory. In triadic encounters, both WB and OB females dominated plain, whereas WB females dominated OB females. Dominance of WB over OB was confirmed using dyadic encounters. In a second experiment, blotched (WB or OB) and plain full-sib sisters were bred by crossing a blotched and a plain parent. In dyadic encounters, WB female morphs dominated their plain sisters, suggesting that dominance of WB females is a pleiotropic effect of color or that genes coding for color and those influencing behavioral dominance are genetically linked, explaining the association between color and behavioral dominance despite gene flow. We conclude that behavioral dominance asymmetries exist among female color morphs of the fish N. omnicaeruleus, and discuss possible mechanisms that may account for the tight association between color and behavioral dominance.

The power of emotional valence – from cognitive to affective processes in reading

The comprehension of stories requires the reader to imagine the cognitive and affective states of the characters. The content of many stories is unpleasant, as they often deal with conflict, disturbance or crisis. Nevertheless, unpleasant stories can be liked and enjoyed. In this fMRI study, we used a parametric approach to examine (1) the capacity of increasing negative valence of story contents to activate the mentalizing network (cognitive and affective theory of mind, ToM), and (2) the neural substrate of liking negatively valenced narratives. A set of 80 short narratives was compiled, ranging from neutral to negative emotional valence. For each story mean rating values on valence and liking were obtained from a group of 32 participants in a prestudy, and later included as parametric regressors in the fMRI analysis. Another group of 24 participants passively read the narratives in a three Tesla MRI scanner. Results revealed a stronger engagement of affective ToM-related brain areas with increasingly negative story valence. Stories that were unpleasant, but simultaneously liked, engaged the medial prefrontal cortex (mPFC), which might reflect the moral exploration of the story content. Further analysis showed that the more the mPFC becomes engaged during the reading of negatively valenced stories, the more coactivation can be observed in other brain areas related to the neural processing of affective ToM and empathy.