Event-related potential effects of object repetition depend on attention and part-whole configuration

The effects of spatial attention and part-whole configuration on recognition of repeated objects were investigated with behavioral and event-related potential (ERP) measures. Short-term repetition effects were measured for probe objects as a function of whether a preceding prime object was shown as an intact image or coarsely scrambled (split into two halves) and whether or not it had been attended during the prime display. In line with previous behavioral experiments, priming effects were observed from both intact and split primes for attended objects, but only from intact (repeated same-view) objects when they were unattended. These behavioral results were reflected in ERP waveforms at occipital-temporal locations as more negative-going deflections for repeated items in the time window between 220 and 300 ms after probe onset (N250r). Attended intact images showed generally more enhanced repetition effects than split ones. Unattended images showed repetition effects only when presented in an intact configuration, and this finding was limited to the right-hemisphere electrodes. Repetition effects in earlier (before 200 ms) time-windows were limited to attended conditions at occipito-temporal sites (N1), a component linked to the encoding of object structure, while repetition effects at central locations during the same time window (P150) were found only from objects repeated in the same intact configuration—both previously attended and unattended probe objects. The data indicate that view-generalization is mediated by a combination of analytic (part-based) representations and automatic view-dependent representations.

The Effect of Dietary Tartrazine on Brain Dopamine and the Behavioral Symptoms of Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder is a neurodevelopmental disorder correlated with a decrease in brain dopamine and an increase in behavioral symptoms of hyperactivity and impulsivity. This experiment explored how tartrazine (Yellow #5) impacts these symptoms. After tartrazine administration to Spontaneously Hypertensive Rats (SHR), dopamine concentrations in regions of brain tissue were measured using Enzyme-Linked Immunosorbent Assay analysis. Behavioral testing with a T-maze and open field test measured impulsivity and hyperactivity, respectively. Results indicate that dietary tartrazine increases hyperactive behaviors in the SHR. However, results do not indicate a relationship between dietary tartrazine and brain dopamine. No conclusions regarding the relationship between dietary tartrazine and impulsivity were drawn.

Childhood Attention Problems and the Development of Comorbid Symptoms at the Transition to High School: The Mediating Role of Parent and Peer Relationships

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) are at increased risk for the development of depression and delinquent behavior. Children and adolescents with ADHD also experience difficulty creating/maintaining high quality friendships and parent-child relationships, and these difficulties may contribute to the development of co-morbid internalizing and externalizing symptoms in adolescence. However, there is limited research examining whether high quality friendships and parent-child relationships mediate the relation between ADHD and the emergence of these co-morbid symptoms at the transition to high school. This study examines the mediating role of relationship quality in the association between ADHD and depressive symptoms/delinquent behaviors at this developmentally significant transition point. Results revealed significant indirect effects of grade 6 attention problems on grade 9 depressive symptoms through friendship quality and quality of the mother-child relationship in grade 8. Interventions targeting parent and peer relationships may be valuable for youth with ADHD to promote successful transitions to high school.

Paradigms that guide the models of attention to the health in Brazil: an analytic essay

SILVA, Flávio César Bezerra da ; COSTA, Francisca Marta de Lima; ANDRADE, Hamilton Leandro Pinto de; FREIRE, Lúcia de Fátima; MACIEL, Patrícia Suerda de Oliveira; ENDERS, Bertha Cruz ; MENEZES, Rejane Maria Paiva de. Paradigms that guide the models of attention to the health in Brazil: an analytic essay. Revista de Enfermagem UFPE On Line., Recife, v.3,n.4, p.460-65. out/dez. 2009. Disponível em < http://www.ufpe.br/revistaenfermagem/index.php/revista/search/results >.

Pseudoneglect and visual attention networks

Pseudoneglect represents the tendency for healthy individuals to show a slight but consistent bias in favour of stimuli appearing in the left visual field. The bias is often measured using variants of the line bisection task. An accurate model of the functional architecture of the visuospatial attention system must account for this widely observed phenomenon, as well as for modulation of the direction and magnitude of the bias within individuals by a variety of factors relating to the state of the participant and/or stimulus characteristics. To date, the neural correlates of pseudoneglect remain relatively unmapped. In the current thesis, I employed a combination of psychophysical measurements, electroencephalography (EEG) recording and transcranial direct current stimulation (tDCS) in an attempt to probe the neural generator(s) of pseudoneglect. In particular, I wished to utilise and investigate some of the factors known to modulate the bias (including age, time-on-task and the length of the to-be-bisected line) in order to identify neural processes and activity that are necessary and sufficient for the lateralized bias to arise. Across four experiments utilising a computerized version of a perceptual line bisection task, pseudoneglect was consistently observed at baseline in healthy young participants. However, decreased line length (experiments 1, 2 and 3), time-on-task (experiment 1) and healthy aging (experiment 3) were all found to modulate the bias. Specifically, all three modulations induced a rightward shift in subjective midpoint estimation. Additionally, the line length and time-on-task effects (experiment 1) and the line length and aging effects (experiment 3) were found to have additive relationships. In experiment 2, EEG measurements revealed the line length effect to be reflected in neural activity 100 – 200ms post-stimulus onset over source estimated posterior regions of the right hemisphere (RH: temporo-parietal junction (TPJ)). Long lines induced a hemispheric asymmetry in processing (in favour of the RH) during this period that was absent in short lines. In experiment 4, bi-parietal tDCS (Left Anodal/Right Cathodal) induced a polarity-specific rightward shift in bias, highlighting the crucial role played by parietal cortex in the genesis of pseudoneglect. The opposite polarity (Left Cathodal/Right Anodal) did not induce a change in bias. The combined results from the four experiments of the current thesis provide converging evidence as to the crucial role played by the RH in the genesis of pseudoneglect and in the processing of visual input more generally. The reduction in pseudoneglect with decreased line length, increased time-on-task and healthy aging may be explained by a reduction in RH function, and hence contribution to task processing, induced by each of these modulations. I discuss how behavioural and neuroimaging studies of pseudoneglect (and its various modulators) can provide empirical data upon which accurate formal models of visuospatial attention networks may be based and further tested.

Attention Deficit Hyperactivity Disorder and Executive Function Impairment: An Overview.

As with any cognitive ability, attention is vulnerable to dysfunction. The most common attentional problem is attention deficit hyperactivity disorder (ADHD). This brief overview will highlight the symptoms and deficits associated with ADHD, its prevalence in today’s society, the association between executive function impairment and ADHD using Barkley’s (1997) work, and the personal and societal effects of the disorder.

Greffage d’un film mince de nano-TiO2 sur les fibres naturelles cellulosiques pour le renforcement de biocomposites polymériques

Abstract : Natural materials have received a full attention in many applications because they are degradable and derived directly from earth. In addition to these benefits, natural materials can be obtained from renewable resources such as plants (i.e. cellulosic fibers like flax, hemp, jute, and etc). Being cheap and light in weight, the cellulosic natural fiber is a good candidate for reinforcing bio-based polymer composites. However, the hydrophilic nature -resulted from the presence of hydroxyl groups in the structure of these fibers- restricts the application of these fibers in the polymeric matrices. This is because of weak interfacial adhesion, and difficulties in mixing due to poor wettability of the fibers within the matrices. Many attempts have been done to modify surface properties of natural fibers including physical, chemical, and physico-chemical treatments but on the one hand, these treatments are unable to cure the intrinsic defects of the surface of the fibers and on the other hand they cannot improve moisture, and alkali resistance of the fibers. However, the creation of a thin film on the fibers would achieve the mentioned objectives. This study aims firstly to functionalize the flax fibers by using selective oxidation of hydroxyl groups existed in cellulose structure to pave the way for better adhesion of subsequent amphiphilic TiO[subscript 2] thin films created by Sol-Gel technique. This method is capable of creating a very thin layer of metallic oxide on a substrate. In the next step, the effect of oxidation on the interfacial adhesion between the TiO[subscript 2] film and the fiber and thus on the physical and mechanical properties of the fiber was characterized. Eventually, the TiO[subscript 2] grafted fibers with and without oxidation were used to reinforce poly lactic acid (PLA). Tensile, impact, and short beam shear tests were performed to characterize the mechanical properties while Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Dynamic mechanical analysis (DMA), and moisture absorption were used to show the physical properties of the composites. Results showed a significant increase in physical and mechanical properties of flax fibers when the fibers were oxidized prior to TiO[subscript 2] grafting. Moreover, the TiO[subscript 2] grafted oxidized fiber caused significant changes when they were used as reinforcements in PLA. A higher interfacial strength and less amount of water absorption were obtained in comparison with the reference samples.

Expertise sportive et entraînement perceptivo-cognitif de l’athlète

Pour être performant au plus haut niveau, les athlètes doivent posséder une capacité perceptivo-cognitive supérieure à la moyenne. Cette faculté, reflétée sur le terrain par la vision et l’intelligence de jeu des sportifs, permet d’extraire l’information clé de la scène visuelle. La science du sport a depuis longtemps observé l’expertise perceptivo-cognitive au sein de l’environnement sportif propre aux athlètes. Récemment, des études ont rapporté que l’expertise pouvait également se refléter hors de ce contexte, lors d’activités du quotidien par exemple. De plus, les récentes théories entourant la capacité plastique du cerveau ont amené les chercheurs à développer des outils pour entraîner les capacités perceptivo-cognitives des athlètes afin de les rendre plus performants sur le terrain. Ces méthodes sont la plupart du temps contextuelles à la discipline visée. Cependant, un nouvel outil d’entraînement perceptivo-cognitif, nommé 3-Dimensional Multiple Object Tracking (3D-MOT) et dénué de contexte sportif, a récemment vu le jour et a fait l’objet de nos recherches. Un de nos objectifs visait à mettre en évidence l’expertise perceptivo-cognitive spécifique et non-spécifique chez des athlètes lors d’une même étude. Nous avons évalué la perception du mouvement biologique chez des joueurs de soccer et des non-athlètes dans une salle de réalité virtuelle. Les sportifs étaient systématiquement plus performants en termes d’efficacité et de temps de réaction que les novices pour discriminer la direction du mouvement biologique lors d’un exercice spécifique de soccer (tir) mais également lors d’une action issue du quotidien (marche). Ces résultats signifient que les athlètes possèdent une meilleure capacité à percevoir les mouvements biologiques humains effectués par les autres. La pratique du soccer semble donc conférer un avantage fondamental qui va au-delà des fonctions spécifiques à la pratique d’un sport. Ces découvertes sont à mettre en parallèle avec la performance exceptionnelle des athlètes dans le traitement de scènes visuelles dynamiques et également dénuées de contexte sportif. Des joueurs de soccer ont surpassé des novices dans le test de 3D-MOT qui consiste à suivre des cibles en mouvement et stimule les capacités perceptivo-cognitives. Leur vitesse de suivi visuel ainsi que leur faculté d’apprentissage étaient supérieures. Ces résultats confirmaient des données obtenues précédemment chez des sportifs. Le 3D-MOT est un test de poursuite attentionnelle qui stimule le traitement actif de l’information visuelle dynamique. En particulier, l’attention sélective, dynamique et soutenue ainsi que la mémoire de travail. Cet outil peut être utilisé pour entraîner les fonctions perceptivo-cognitives des athlètes. Des joueurs de soccer entraînés au 3D-MOT durant 30 sessions ont montré une amélioration de la prise de décision dans les passes de 15% sur le terrain comparés à des joueurs de groupes contrôles. Ces données démontrent pour la première fois un transfert perceptivo-cognitif du laboratoire au terrain suivant un entraînement perceptivo-cognitif non-contextuel au sport de l’athlète ciblé. Nos recherches aident à comprendre l’expertise des athlètes par l’approche spécifique et non-spécifique et présentent également les outils d’entraînements perceptivo-cognitifs, en particulier le 3D-MOT, pour améliorer la performance dans le sport de haut-niveau.

Testosterone and attention deficits as possible mechanisms underlying impaired emotion recognition in intimate partner violence perpetrators

Several studies have reported impairments in decoding emotional facial expressions in intimate partner violence (IPV) perpetrators. However, the mechanisms that underlie these impaired skills are not well known. Given this gap in the literature, we aimed to establish whether IPV perpetrators (n = 18) differ in their emotion decoding process, attentional skills, and testosterone (T), cortisol (C) levels and T/C ratio in comparison with controls (n = 20), and also to examine the moderating role of the group and hormonal parameters in the relationship between attention skills and the emotion decoding process. Our results demonstrated that IPV perpetrators showed poorer emotion recognition and higher attention switching costs than controls. Nonetheless, they did not differ in attention to detail and hormonal parameters. Finally, the slope predicting emotion recognition from deficits in attention switching became steeper as T levels increased, especially in IPV perpetrators, although the basal C and T/C ratios were unrelated to emotion recognition and attention deficits for both groups. These findings contribute to a better understanding of the mechanisms underlying emotion recognition deficits. These factors therefore constitute the target for future interventions.

Risperidone Versus Methylphenidate in Treatment of Preschool Children With Attention-Deficit Hyperactivity Disorder

Background: Attention Deficit Hyperactivity Disorder (ADHD) is a common psychiatric diagnosis among preschool children. Objectives: The aim of this study was to examine the Risperidone treatment compared to Methylphenidate (MPH) in preschool children with ADHD. Patients and Methods: Thirty three outpatient preschool children, aged 3-6 years, diagnosed with ADHD (The diagnosis of ADHD was established by two child and adolescent psychiatrists according to the DSM-IV-TR criteria), participated in a 6-week, double-blind clinical trial with risperidone (0.5-1.5 mg/d) and methylphenidate (5-20 mg/d), in two divided doses. Treatment outcomes were assessed using the Parent ADHD Rating Scale and Conners Rating Scale. Patients were assessed by a child psychiatrist at baseline, 2, 4 and 6 weeks after the medication started. Side effects were also rated by side effects questionnaire. Results: There were no significant differences between the two protocols on the Parent ADHD Rating Scale scores (P > 0.05) and Parent Conners Rating Scale scores (P > 0.05). Both groups showed a significant improvement in ADHD symptoms over the 6 weeks of treatment for parent ADHD Rating Scale (P < 0.001) and Parent Conners Rating Scale (P < 0.001). The most common adverse effects seen with risperidone were daytime drowsiness and anorexia (20%), and with methylphenidate it was anorexia (55%). Conclusions: Results of this study show that risperidone may be effective and well tolerated for ADHD in preschool children, but more researches are needed to clarify the potential benefits and adverse effects in long term use and comorbid conditions.

Co-creation of tourism experience: attention, involvement and memorability

Tese de Doutoramento, Turismo, Faculdade de Economia, Universidade do Algarve, 2016

The Effect of Stress Management Program Using Cognitive Behavior Approach on Mental Health of the Mothers of the Children With Attention Deficit Hyperactivity Disorder

Background: Attention deficit hyperactivity disorder is one of the most common psychiatric disorders in children. Objectives: The study aimed to evaluate the effectiveness of stress management program using cognitive behavior approach on mental health of the mothers of the children with attention deficit hyperactivity disorder. Patients and Methods: In this interventional study, 90 mothers of the children with attention deficit hyperactivity disorder were randomly allocated into three intervention, placebo, and control groups. The general health questionnaire was used to measure mental health. Besides, stress was assessed through the depression-anxiety-stress scale. The two instruments were completed at baseline, immediately after, and one month after the intervention by the mothers. Afterwards, within group comparisons were made using one-sample repeated measurement ANOVA. One-way ANOVA was used for inter group comparisons. Mothers in the placebo group only participated in meetings to talk and express feelings without receiving any interventions. Results: At the baseline, no significant difference was found among the three groups regarding the means of stress, anxiety, depression, and mental health. However, a significant difference was observed in the mean score of stress immediately after the intervention (P = 0.033). The results also showed a significant difference among the three groups regarding the mean score of mental health (P < 0.001). One month after the intervention, the mean difference of mental health score remained significant only in the intervention group (P < 0.001). Conclusions: The study findings confirmed the effectiveness of stress management program utilizing cognitive behavior approach in mental health of the mothers of the children with attention deficit hyperactivity disorder.

Attention Deficit Hyperactivity Disorder in a Patient With Congenital Mirror Movement Disorder and Colpocephaly

Introduction: Congenital mirror movement disorder designates involuntary movements on one side of the body that occur as mirror of the intentional movements on the contralateral side. Colpocephaly is described as persistence of fetal configuration of lateral ventricles. Case Presentation: A two-month old male infant was brought to the hospital due to bilateral identical movements of the hands. Except for bilateral involuntary synkinetic imitative movements in hands, neurological and physical examination was normal. Cranial MRI showed corpus callosum dysgenesis, hypogenesis and dilation of bilateral lateral ventricular posterior horns (colpocephaly). At the age of 7 years, he was started to use metylphenydate to mitigate attention deficit and hyperactivity disorder. The mirror movements were decreasing in amplitude by years and were not so serious to affect normal life activities. Conclusions: Mirror movements, diagnosed usually during childhood, may be congenital or secondary to neurological diseases. Although they generally do not affect normal life activities, in some cases severity of mirror movements causes a real debilitating disease. In our case the patient was diagnosed at the age of 2 months and on follow-up no debilitating problems were observed. This is the first case to describe the association of colpocephaly and mirror movements. The exact mechanism of this association is not known. Although it is known that mirror movements may be in relation with some pychiatric pathologies, this is the first report of attention deficit and hyperactivity disorder in conjunction with mirror movements and/or colpocephaly. Managing comorbidities, either physical or psyhchological, will help the patient to live in good health without trying to cope with other pathological diseases.

A short treatise on the game of whist : containing the laws of the game and also some rules whereby a beginner may, with due attention to them attain to the playing it well ... /

In folder.