Spectral differences in resting-state EEG associated to individual Emotional Styles.

The ability to manage the emotions has been associated to the Emotional Styles (ES), a set of coherent ways to deal with life's experiences. Recently, the Emotional Style Questionnaire (ESQ) has been proposed as a self-report mea-sure to assess the individual ES. The present study investigates the spectral differences in the resting-state EEG due to the individual ES, in order to support the psychometric reliability of the ESQ with associated neurophysiological measurements. In the alpha and beta band, Social Intuition showed significant and large (d > 0.8) effect sizes on the parietal and parieto-occipital regions, as well as a significant and large effect size in the gamma band on the pre-frontal region. In the beta band, Attention showed a significant and large effect size on the parieto-occipital region.

It's a Question of Methods: Computational Factors Influencing the Frontal Asymmetry in Measuring the Emotional Valence.

The prefrontal asymmetry (FA) in the alpha band is a well-known physiological correlate of the emotional valence. Several methods for assessing the FA have been proposed in literature, but no studies have compared their effectiveness in a comprehensive way. In this study we first investigated whether the association between FA and valence depends on the computational methods and then, we identified the best one, namely the one giving the highest correlation with the self-reports. The investigated factors were the presence of a normalization factor, the computation in time or frequency domain and the cluster of electrodes used. All the analyses were implemented on the validated DEAP dataset. We found that the number and position of the electrodes do not influence the FA, in contrast with both the power computation method and the normalization. By using a spectrogram-based approach and by adding a normalization factor, a correlation of 0.36 between the FA and the self-reported valence was obtained.

Yellow (Lens) Better: Bioelectrical and Biometrical Measures to Assess Arousing and Focusing Effects.

Colours can induce several psychological effects, conditioning perceptions, cognitive/emotional states and human performances. In this exploratory study we investigated the effect of a yellow light exposure, obtained filtering the ambient light with coloured glasses, on the human's psychological functioning. In particular we wanted to assess if people are more able to focus when exposed to a yellow light. We recorded EEG, SC, HR and gaze-related data from 16 subjects (50% split in experimental and control group) during the execution of a reactivity test (the Hazard Perception Test, HPT). Compared with the control group, the experimental group showed increases in concentration, focus, visual attention and arousal, as measured by increases of first fixation duration and Beta over-Alpha ratio (BAR) as well as by decreases of distraction, workload, and number of gaze revisits.

Emotion assessment using Machine Learning and low-cost wearable devices.

The advancement in bioelectrical measurement technologies and the push towards a higher impact of the Brain Computer Interfaces and Affective Computing in the daily life have made non-invasive and low-priced devices available to the large population to record physiological states. The aim of this study is the assessment of the abilities of the MUSE headband, together with the Shimmer GSR+ device, to assess the emotional state of people during stimuli exposure. Twenty-four pictures from the IAPS database were showed to 54 subjects and were evaluated in their emotional values by means of the Self-Assessment Manikin (SAM). Using a Machine Learning approach, fifty-two scalar features were extracted from the signals and used to train 6 binary classifiers to predict the valence and arousal elicited by each stimulus. In all classifiers we obtained accuracies ranging from 53.6% to 69.9%, confirming that these devices are able to give information about the emotional state.

Neurocoaching: exploring the relationship between coach and coachee by means of bioelectrical signal similarities.

Coaching aims to unlock the human's potential, self-awareness and responsibility, improving the professional performances and the personal satisfaction. Its effectiveness is known to depend on the degree of bonding and mutual engagement of the coaching relationship. In this exploratory study we recorded synchronised EEG and SC data from both coach and coachee during 36 individual sessions, performed following 2 different coaching methods. Our principal aim was to investigate the temporal evolution of the bonding and the mutual engagement along the different steps of a session, by means of a "similarity" metric based on the DTW distance between signals (namely, S-TVM). We found significant differences between session phases for the EEG-related S-TVMs (BAR, BATR and AWI), with maximum values (defined as "tuning") all in the same phase, but differentiated between the two experiments. The results suggest a temporal concurrency of the engagement and emotional tunings, whose specific location seems to be a function of the coaching approach.

Looking through blue glasses: bioelectrical measures to assess the awakening after a calm situation.

Colors can elicit cognitive and emotional states. In particular, blue colour is associated to "refresh" and "restart" effects and is suggested to enhance a wake-up after a calm situation. In this exploratory study, these claims are investigated using Electroencephalographic (EEG), Skin Conductance (SC) and pupil diameter data. The results confirmed the "wake-up effect" for subjects wearing the lenses, as measured by Global Field Power (GFP) in Theta Band, Skin Conductance Response (SCR) and pupil diameter data.

Ascertainment bias in dementias: a secondary to tertiary centre analysis in Central Italy and conceptual review.

BACKGROUND AND AIMS: Ascertainment bias (AB) indicates a bias of an evaluation centre in estimating the prevalence/incidence of a disease due to the specific expertise of the centre. The aim of our study was to evaluate classification of different types of dementia in new cases appearing in secondary and tertiary centres, in order to evidence possible occurrence of AB in the various (secondary to tertiary) dementia centres. METHODS: To assess the mechanism of AB, the rates of new cases of the different forms of dementia reported by different centres were compared. The centres involved in the study were 11 hospital-based centres including a tertiary centre, located in the University Department of Clinical Neurology. The tertiary centre is endowed with state-of-the-art diagnostic facilities and its scientific production is prominently focused on dementia with Lewy bodies (DLB) thus suggesting the possible occurrence of a bias. Four main categories of dementia were identified: Alzheimer's disease (AD), DLB, fronto-temporal dementia (FTD), vascular dementia (VaD), with other forms in a category apart. The classification rate of new cases of dementia in the tertiary centre was compared with rates reported by secondary centres and rates of recoding were calculated during a follow-up of 2 years. RESULTS: The study classified 2,042 newly diagnosed cases of dementia in a population of 1,370,000 inhabitants of which 315,000 were older than 65. AD was categorized in 48-52 % of cases, DLB in 25-28 %, FTD in 2-4 % and VaD in 17-28 %. During the 2-year follow-up the diagnosis was re-classified in 40 patients (3 %). The rate of recoding was 5 % in the tertiary centre, 2-8 % in referrals from secondary to tertiary centre, 2-10 % in recodings performed in secondary centres and addressed to tertiary centre. Recoding or percentages of new cases of AD or DLB were not different in the comparison between secondary or between secondary and tertiary centres. FTD and VaD were instead significantly recoded. CONCLUSION: The results of the study suggest that in a homogeneous area, AB is not interfering with diagnosis of AD or DLB.

Depletion of systemic macrophages by liposome-encapsulated clodronate attenuates striatal macrophage invasion and neurodegeneration following local endotoxin infusion in gerbils.

CNS-localized inflammation with microglial activation and macrophage infiltration contributes to the pathogenesis of a broad spectrum of neurologic diseases. A direct injection of lipopolysaccharide (LPS) into the striatum of gerbils induced lectin-positive macrophage parenchymal invasion, minimal local microglial staining but extensive neurodegeneration (cresyl violet and silver staining) when evaluated 4 days later. In mice, LPS activated microglia (increased lectin staining of morphologically identified cells) with substantially less macrophage invasion but no neurodegeneration was seen at 4 days post LPS infusion. To evaluate the role of infiltrating macrophages in the neurodegenerative response in gerbils, peripheral macrophages were depleted by an intravenous injection of liposome-encapsulated clodronate. This preparation depleted spleen and liver macrophages (>95%), decreased blood monocytes by 55% and attenuated striatal macrophage infiltration (32 to 73% in five representative sections). Notably, the liposome-encapsulated clodronate reduced the severity of LPS-induced neurodegeneration, as visualized by cresyl violet staining and quantified in 20 serially stained silver sections (total volume, 1.32+/-0.41 mm(3) in liposome-encapsulated clodronate-treated versus 3.04+/-0.72 mm(3) in saline-treated controls). These results indicate that a local LPS infusion in gerbil brain may be a useful model in which to investigate the role of invading macrophages and other inflammatory responses in neurodegeneration in inflammatory neurological disease.

Change in bone mass after Colles' fracture: a case report on unique data collection and long-term implications.

The cast immobilization of a fractured limb results in a loss of bone mass; however, the long-term implications of that effect with regard to bone mineral status, particularly in other skeletal sites, are less known. The purpose of this study was to describe changes in bone mass in different skeletal sites triggered by Colles' fracture. The case is unique regarding the existence of baseline measurements taken just a few days before the fracture on all measurable skeletal sites, including the fractured radius. Therefore, it was also possible to determine whether the injury caused long-term bone loss in the affected and unaffected skeletal sites. The patient was a healthy, premenopausal Caucasian woman, in her late forties, who fractured her nondominant wrist as a result of low-impact fall on ice. The arm and the metacarpals were immobilized to the elbow for 5 wk. Bone mass measurements were performed with DPX-MD densitometer (Lunar Corp. Madison, WI) at baseline and 5, 10, 13, 21, and 52 wk postinjury. At the 5-wk measurement (on plaster removal) there was a notable increase in bone mineral density (BMD) and bone mineral content (BMC) in all sites of ulna and radius of the injured forearm (from 10 to 73%), followed by the apparent decline to or below the baseline at 10, 13, 21 and 52 wk of follow-up. Other skeletal sites were measured at 10 wk when a substantial decrease in BMD and BMC in some of the hip regions and lumbar spine was noticed; most notably in L3-L4, Ward's triangle, and femoral neck (from 2 to 8%) and remained such after 1 yr. Although this patient had a normal bone mineral status and no osteopenia detected before fracture, the trauma of radial fracture caused long-standing bone loss in fracture-prone areas-hip and spine. Because about 70% of bone strength is explained by its mineral density, the patient might be at increased risk for fracture later in life. The changes in bone mass after injury should be monitored and interpreted carefully, and more elaborate treatment of patients presenting with wrist fractures are needed to prevent any potential risk for later osteoporotic fractures in spine and hip and possible refracture of the injured extremity.

Depletion of systemic macrophages by liposome-encapsulated clodronate attenuates increases in brain quinolinic acid during CNS-localized and systemic immune activation.

Quinolinic acid is a neurotoxic tryptophan metabolite produced locally during immune activation. The present study tested the hypothesis that macrophages are an important source. In normal gerbils, the macrophage toxin liposome-encapsulated clodronate depleted blood monocytes and decreased quinolinic acid levels in liver (85%), duodenum (33%), and spleen (51%) but not serum or brain. In a model of CNS inflammation (an intrastriatal injection of 5 microg of lipopolysaccharide), striatal quinolinic acid levels were markedly elevated on day 4 after lipopolysaccharide in conjunction with infiltration with macrophages (lectin stain). Liposome-encapsulated clodronate given 1 day before intrastriatal lipopolysaccharide markedly reduced parenchymal macrophage invasion in response to lipopolysaccharide infusion and attenuated the increases in brain quinolinic acid (by 60%). A systemic injection of lipopolysaccharide (450 microg/kg) increased blood (by 38-fold), lung (34-fold), liver (23-fold), spleen (8-fold), and striatum (25-fold) quinolinic acid concentrations after 1 day. Liposome-encapsulated clodronate given 4 days before systemic lipopolysaccharide significantly attenuated the increases in quinolinic acid levels in blood (by 80%), liver (87%), spleen (80%), and striatum (68%) but had no effect on the increases in quinolinic acid levels in lung. These results are consistent with the hypothesis that macrophages are an important local source of quinolinic acid in brain and systemic tissues during immune activation.

Treatment of hypertension in the elderly.

Several trials performed in elderly patients have demonstrated that antihypertensive drugs are effective in both systo-diastolic and isolated systolic hypertension, reducing the incidence of fatal and nonfatal cardiovascular events. However because of technical and design problems, the studies carried out to date have involved highly selected patients, almost always without any target organ damage, independent, cognitively normal and with low comorbidity. Therefore, trial results may be transferred to clinical practice only with some caution. Therapeutic behavior could be different in the presence of diseases associated with hypertension: a) in case of associated specific cardiovascular complications and/or diseases, such as diabetes or dyslipidemia, which could increase cardiovascular risk, treatment must be more aggressive; b) in case of associated diseases with fatal prognosis, treatment is aimed at preventing hypertensive emergencies; c) in case of associated diseases, which are not life-threatening but require chronic pharmacological intervention, drug interaction must be carefully considered. Finally, sudden and significant blood pressure drops due both to overdosage of antihypertensive drugs and/or to intercurrent illnesses must be prevented, because the reduction of blood flow may induce severe target organ ischemia.

Blood pressure rhythm and prevalence of vascular events in hypertensive subjects.

OBJECTIVES: To evaluate the influence of age on the day-night blood pressure rhythm and on the prevalence of vascular events in those whose systolic blood pressure (SBP) fell by <10% overnight (non-dippers). DESIGN: Cross-sectional observational cohort study. SETTING: Outpatient hypertension clinic. PARTICIPANTS: 419 Hypertensive patients (214 male, 205 female). METHODS: All subjects were submitted to ambulatory blood pressure monitoring (Spacelabs 90207). The nocturnal fall of SBP was calculated from (day SBP--night SBP)/day SBP, where 'day' values were recorded between 0600 h and 2200 h and 'night' values between 2200 h and 0600 h. Dippers and non-dippers were divided in two subgroups according to age (under or over 65 years). Information on gender, smoking, diabetes mellitus and body mass index was collected and cerebrovascular and cardiovascular events, evaluated by history and medical records, were registered. RESULTS: The day-night difference in blood pressure significantly decreased with age and the prevalence of non-dippers was greater in elderly than in younger subjects (65.1% vs. 29.8%). No difference was found between groups for cerebrovascular events, irrespective of age. A relationship between non-dipping pattern and cardiovascular events was found only in younger hypertensive non-dippers (odds ratio, 2.0; 95% confidence interval, 1.20-3.21); in elderly people the prevalence of cardiovascular events was similar in dippers and non-dippers. CONCLUSIONS: Cardiovascular risk is not increased in elderly non-dipper hypertensive subjects. This contrasts with results in younger populations.

Are vascular factors involved in Alzheimer's disease? Facts and theories.

The hypothesis that vascular factors may contribute to the development of Alzheimer's disease (AD) is supported by epidemiologic and pathologic observations. Arterial hypertension and diabetes have been found to be associated not only with vascular dementia, but also with AD; in addition, the treatment of hypertension with calcium antagonists seems to prevent degenerative dementias. Hypertension and hyperinsulinemia favor the deposition of amyloid substance in the brain. The histopathology of AD is marked not only by neurofibrillary tangles and senile plaques, but also by macro and micro congophilic angiopathy and ischemic white matter rarefaction. The specific AD pathological lesions, if isolated, are not able to lead to an evident clinical picture of dementia, which, on the contrary, becomes evident when vascular, mainly subcortical, lesions are associated. These and other observations suggest that vascular factors may have a role in the development of AD. An aggressive approach to these factors could be of value in the prevention of AD.

Species heterogeneity between gerbils and rats: quinolinate production by microglia and astrocytes and accumulations in response to ischemic brain injury and systemic immune activation.

Quinolinic acid is an excitotoxic kynurenine pathway metabolite, the concentration of which increases in human brain during immune activation. The present study compared quinolinate responses to systemic and brain immune activation in gerbils and rats. Global cerebral ischemia in gerbils, but not rats, increased hippocampus indoleamine-2,3-dioxygenase activity and quinolinate levels 4 days postinjury. In a rat focal ischemia model, small increases in quinolinate concentrations occurred in infarcted regions on days 1, 3, and 7, although concentrations remained below serum values. In gerbils, systemic immune activation by an intraperitoneal injection of endotoxin (1 mg/kg of body weight) increased quinolinate levels in brain, blood, lung, liver, and spleen, with proportional increases in lung indoleamine-2,3-dioxygenase activity at 24 h postinjection. In rats, however, no significant quinolinate content changes occurred, whereas lung indoleamine-2,3-dioxygenase activity increased slightly. Gerbil, but not rat, brain microglia and peritoneal monocytes produced large quantities of [13C(6)]-quinolinate from L-[13C(6)]tryptophan. Gerbil astrocytes produced relatively small quantities of quinolinate, whereas rat astrocytes produced no detectable amounts. These results demonstrate that the limited capacity of rats to replicate elevations in brain and blood quinolinic acid levels in response to immune activation is attributable to blunted increases in local indoleamine-2,3-dioxygenase activity and a low capacity of microglia, astrocytes, and macrophages to convert L-tryptophan to quinolinate.

Lasting effects of one bout of two 15-second passive stretches on ankle dorsiflexion range of motion.

Although passive stretching is widely used, the parameters of stretching necessary to achieve a lasting length have not been determined. This study investigated the lasting effects of one bout of two 15-second passive stretches on ankle dorsiflexion range of motion. Conducting this study was important because, while it focused on a sufficient minimum duration, it considered lengthening mechanisms thought to contribute to a lasting length. Nineteen healthy volunteers with symmetrical limitations of ankle dorsiflexion participated. Stretching was done in unilateral standing with the subject's heel suspended over the edge of a platform. Four 5-second active dorsiflexion contractions were used as a preconditioning intended to stabilize the effects of mechanisms providing temporary length gains and were found to be effective. Measurements of passive dorsiflexion range of motion were taken over 24 hours. This study found no statistically significant length gains using a single bout of two 15-second stretches. These data do not provide evidence of lasting lengthening at this duration. Further research to determine a minimum one-bout lasting length duration is encouraged.

Continuous measurement of vascular access recirculation by conductivity.

Vascular access recirculation is one of the main factors influencing dialysis efficiency. The underestimation of or mistakes in the measurement of access recirculation causes a discrepancy between dialysis prescription and the actual dose of dialysis administered. Moreover, access recirculation is known to increase during a dialysis session. Therefore, the evaluation of recirculation is necessary to correctly prescribe dialysis and the ideal measurement method should be very accurate and feasible at any moment during a dialysis session.

Blood pressure and intellectual function in elderly subjects.

OBJECTIVE: to assess the relationship between hypertension and cognitive function in elderly subjects. METHODS: 17 subjects with uncomplicated hypertension (nine male, eight female) and 27 control subjects with similar educational level and age (18 male, nine female) were studied. These individuals were recruited, according to strict selection criteria, from a random sample of 120 elderly subjects living in the community, who had a normal Mini Mental State score. An extensive neuropsychological test battery, sensitive to mild cognitive impairment, was administered in standard conditions to measure attention, concentration and judgement, psychomotor speed, memory and learning. Affective disorders were also evaluated. In all patients a computed tomography scan was performed. RESULTS: subjects with high blood pressure had lower mean levels of performance in attentional measures; tapping test (inhibition of incorrect answers), three words-three shapes test (attempts; incidental memory) and reaction time to multiple stimuli. They also scored worse in clusters 1 and 2 of the Hamilton rating scale for depression. Confluent white matter lesions were found in nine hypertensive subjects (52.9%) and five controls (18.5%; P = 0.0170). Lacunes were demonstrated in 11 hypertensive (64.7%) and four normotensive people (14.8%; P = 0.0007). In a multivariate analysis (logistic regression), three cognitive variables (tapping, Hamilton cluster 2 and Hamilton total score) remained significantly associated with hypertension, independently of the presence of cerebral lesions. CONCLUSIONS: in elderly otherwise normal hypertensive subjects, an attentional impairment may occur, which appears to be functional and possibly reversible rather than structural and progressive.

Autonomic nervous activity in elderly dipper and non-dipper patients with essential hypertension.

The pathogenetic mechanisms of the blunted nocturnal fall in blood pressure, frequently observed in elderly patients with essential hypertension, are unclear. The aim of this study was to evaluate the autonomic nervous system in elderly dipper and non-dipper hypertensive subjects. The study group consisted of twelve non-dipper and twelve dipper hypertensive patients (mean age 77.7 and 73.8 years, respectively). Non-dippers were defined as subjects whose nocturnal fall in systolic blood pressure (SBP), evaluated by means of Ambulatory Blood Pressure Monitoring, was less than 10% of diurnal SBP. All the patients underwent the following cardiovascular tests to explore autonomic function: Tilt Table, Valsalva Maneuver, Deep Breathing, Cough. The tests were performed under standard conditions, and heart rate and blood pressure were continuously recorded. Valsalva ratio (VR), Expiration/Inspiration Ratio (E/IR) and Cough Test Ratio (CTR) were calculated. Mann Whitney's and chi 2 tests were used for comparison between groups. Relationships were assessed by univariate and multivariate analyses. Non-dipper hypertensive subjects showed significantly lower scores in VR (11.1 +/- 0.08 vs 1.28 +/- 0.14), E/IR (1.11 +/- 0.07 vs 1.21 +/- 0.10), and CTR (1.07 +/- 0.02 vs 1.15 +/- 0.07). During the tilt test, a significant decrease in SBP and a late increase in heart rate were observed in non-dippers. The day-night difference in SBP was significantly related to VR, CTR and maximal SBP drop during tilting. The findings confirm that non-dippers show an impairment in autonomic nervous drive, which is characterized mainly by decreased parasympathetic activity. These observations may explain the increase in cardiovascular risk in non-dippers.