Attentional processes link perception and action

Behavioural studies on normal and brain-damaged individuals provide convincing evidence that the perception of objects results in the generation of both visual and motor signals in the brain, irrespective of whether or not there is an intention to act upon the object. In this paper we sought to determine the basis of the motor signals generated by visual objects. By examining how the properties of an object affect an observer's reaction time for judging its orientation, we provide evidence to indicate that directed visual attention is responsible for the automatic generation of motor signals associated with the spatial characteristics of perceived objects.

Constraints on the spatiotemporal accuracy of interceptive action: effects of target size on hitting a moving object

Results of two experiments are reported that examined how people respond to rectangular targets of different sizes in simple hitting tasks. If a target moves in a straight line and a person is constrained to move along a linear track oriented perpendicular to the targetrsquos motion, then the length of the target along its direction of motion constrains the temporal accuracy and precision required to make the interception. The dimensions of the target perpendicular to its direction of motion place no constraints on performance in such a task. In contrast, if the person is not constrained to move along a straight track, the targetrsquos dimensions may constrain the spatial as well as the temporal accuracy and precision. The experiments reported here examined how people responded to targets of different vertical extent (height): the task was to strike targets that moved along a straight, horizontal path. In experiment 1 participants were constrained to move along a horizontal linear track to strike targets and so target height did not constrain performance. Target height, length and speed were co-varied. Movement time (MT) was unaffected by target height but was systematically affected by length (briefer movements to smaller targets) and speed (briefer movements to faster targets). Peak movement speed (Vmax) was influenced by all three independent variables: participants struck shorter, narrower and faster targets harder. In experiment 2, participants were constrained to move in a vertical plane normal to the targetrsquos direction of motion. In this task target height constrains the spatial accuracy required to contact the target. Three groups of eight participants struck targets of different height but of constant length and speed, hence constant temporal accuracy demand (different for each group, one group struck stationary targets = no temporal accuracy demand). On average, participants showed little or no systematic response to changes in spatial accuracy demand on any dependent measure (MT, Vmax, spatial variable error). The results are interpreted in relation to previous results on movements aimed at stationary targets in the absence of visual feedback.

Expertise and the perception of kinematic and situational probability information

Two experiments were conducted on the nature of expert perception in the sport of squash. In the first experiment, ten expert and fifteen novice players attempted to predict the direction and force of squash strokes from either a film display (occluded at variable time periods before and after the opposing player had struck the ball) or a matched point-light display (containing only the basic kinematic features of the opponent's movement pattern). Experts outperformed the novices under both display conditions, and the same basic time windows that characterised expert and novice pick-up of information in the film task also persisted in the point-light task. This suggests that the experts' perceptual advantage is directly related to their superior pick-up of essential kinematic information. In the second experiment, the vision of six expert and six less skilled players was occluded by remotely triggered liquid-crystal spectacles at quasi-random intervals during simulated match play. Players were required to complete their current stroke even when the display was occluded and their prediction performance was assessed with respect to whether they moved to the correct half of the court to match the direction and depth of the opponent's stroke. Consistent with experiment 1, experts were found to be superior in their advance pick-up of both directional and depth information when the display was occluded during the opponent's hitting action. However, experts also remained better than chance, and clearly superior to less skilled players, in their prediction performance under conditions where occlusion occurred before any significant pre-contact preparatory movement by the opposing player was visible. This additional source of expert superiority is attributable to their superior attunement to the information contained in the situational probabilities and sequential dependences within their opponent's pattern of play.

The perception of Executives and other Employees on the answer to the Sarbanes-Oxley: case study of a subsidary of the American auto industry established in Brazil

To attend and obtain the systems and. internal controls mechanisms proposed by Sarbanes-Oxley certifications is actually a big challenge,for most of the multinational companies registered in SEC (US Securities and Exchange Commission). This work has the objective of contributing to the analysis of this methodology, not only to attend the law but to reduce cost and generate value through the strengthen of the internal control systems, turning them into animating value generation process mechanisms. So, the idea is to identify the main gaps in the theory through the literature revision and a case study in order to put a question to the main deficiencies, strong points or contributions through the evaluation of the noticed practices. Finally, we can say that a a result of the research and the analyses made in. this case, the vast majority of executives and other employees recognize the benefit that Sarbanes-Oxley Act has brought to the company searched. Also recognize that, although there is still necessity for systemic adequacy and infrastructure, it helps and reinforce reducing and controlling the risks. the system of internal controls in all areas of expertise. They approach and understand that there is the need for a change in the other employees` culture to be inserted in the day-today routine as internal controls, attention to Sarbanes-Oxley and Corporate Governance, making the control cost smaller when compared to the benefits generated.

Customer Perception about Loyalty Programs in Agricultural Market: a case study

This study discusses the use of loyalty programs and Customer perception in, agricultural market. The theoretical review includes relationship marketing, its objectives, dimensions and instruments, and loyalty programs. The method for the empirical part consisted on qualitative research, through a case study conducted at one of the largest crop protection chemical companies in Brazil. The case is representative once this company was pioneer in its segment in adopting the customer relationship management. (CRM) approach to-their clients: It has been a consensus that customer relationship is a tool to amplify the Customer share. This.,is so, due the. increasing competition generated by the entrance of generic products and the retaliation actions adopted by the multinational groups. The case study includes a market overview, a description of the company, its loyalty program, the image of the program from the customer`s perspective, and the main results acquired with the CRM program. The Study also presents some recommendations for-companies that are pursuing strategies to. increase their customer share through loyalty programs.

Speech perception in adolescents with pre-lingual hearing impairment with cochlear implants

Profound hearing loss is a disability that affects personality and when it involves teenagers before language acquisition, these bio-psychosocial conflicts can be exacerbated, requiring careful evaluation and choice of them for cochlear implant. Aim: To evaluate speech perception by adolescents with profound hearing loss, users of cochlear Implants. Study Design: Prospective. Materials and Methods: Twenty-five individuals with severe or profound pre-lingual hearing loss who underwent cochlear implantation during adolescence, between 10 to 17 years and 11 months, who went through speech perception tests before the implant and 2 years after device activation. For comparison and analysis we used the results from tests of four choice, recognition of vowels and recognition of sentences in a closed setting and the open environment. Results: The average percentage of correct answers in the four choice test before the implant was 46.9% and after 24 months of device use, this value went up to 86.1% in the vowels recognition test, the average difference was 45.13% to 83.13% and the sentences recognition test together in closed and open settings was 19.3% to 60.6% and 1.08% to 20.47% respectively. Conclusion: All patients, although with mixed results, achieved statistical improvement in all speech tests that were employed.

Does affirmative action reduce effort incentives? A contest game analysis

In this paper a contest game with heterogeneous players is analyzed in which heterogeneity could be the consequence of past discrimination. Based on the normative perception of the heterogeneity there are two policy options to tackle this heterogeneity: either it is ignored and the contestants are treated equally, or affirmative action is implemented which compensates discriminated players. The consequences of these two policy options are analyzed for a simple two-person contest game and it is shown that the frequently criticized trade-off between affirmative action and total effort does not exist: Instead, affirmative action fosters effort incentives. A generalization to the n-person case and to a case with a partially informed contest designer yields the same result if the participation level is similar under each policy.

Copwatching et perception publique de la police. L'intervention policière comme performance sous surveillance

Envisagée comme une situation sociale de rassemblement en rue, l'intervention policière se caractérise par sa nature publique et observable. Le « copwatching », en tant que pratique amateur de captation vidéo des interventions de police, problématise la visibilité des agents sur la voie publique en les soumettant à une surveillance médiatique. M'appuyant sur des exemples vidéos, j'explore les dimensions visuelles et symboliques du travail policier. De la performance policière en rue à la figuration médiatique du policier, l'étude des médiations entre action et image permet d'interroger la perception publique de la police engagée dans les rassemblements. Abstract Cop-watching and the public perception of the police. Police intervention as performance under surveillance. This paper deals with police work as a public performance on the street. Cop-watching, a way of publicly observing and documenting police activities, reveals the complex relationship between public perceptions of law enforcement and the visual nature of much police work. Three methodological approaches to cop-watching videos allow us to highlight the visual dimensions of police work : the study of mass-media images of cops, the study of street performance by real cops, and the study of the ways people make sense of the visual symbolic environment present in everyday police work.

Acid-sensing ion channels : modulation by serine-proteases and involvement in acid-induced action potential generation in hippocampal neurons

SUMMARY Acid-sensing ion channels (ASICs) are non-voltage gated sodium channels. They are activated by rapid extracellular acidification and generate an inactivating inward current. Four ASIC genes have been cloned: ASIC1, 2, 3 and 4, with variants a and b for ASIC1and AS1C2. ASICs are expressed in neurons of the central (CNS) and peripheral nervous system (PNS). In the CNS, ASICs have a role in learning, memory, as well as in neuronal death in ischemia. In the PNS, ASICs are involved in the perception of acid-induced pain, as well as in mechanoperception. In one part of my thesis project, we addressed the question of the mechanism of regulation of ASIC1 a by the serine protease trypsin at the molecular level. Trypsin modifies the function of ASIC1 a but not of ASIC1b. In order to identify the channel region responsible for this effect, we created chimeras between ASIC1 a and 1b. Subsequently, to identify the exact trypsin target(s), we mutated predicted trypsin sites in the region identified by the chimera. In the second part of a project, we investigated the role of ASICs at the cellular level, in neuronal signaling. Using the whole-cell patch clamp in hippocampal neuronal culture, we studied the potential involvement of ASICs in action potential (AP) generation. In the first part of the thesis work, we showed that trypsin modifies ASIC1a function: it shifts the pH activation and the steady-state inactivation curve towards more acidic values and accelerates the time course of the channel recovery from inactivation. We also showed that trypsin cleaves ASIC1a and that the functional effect and a channel cleavage correlate. In the inactivated state, channels cannot be modified by trypsin. Cleavage occurs in a channel region that is also important for inactivation of all ASICs; a part of this region is critical for the inhibition of ASIC1 a by the spider toxin Psalmotoxin1. In the second part of the thesis work, we showed that ASIC activity can modulate AP generation. ASIC activity by itself can induce trains of APs. In situations in which this activity by itself is not sufficient to induce APs, it can contribute to AP generation. During high neuronal activity, ASIC activity can block already existing trains of APs. In conclusion, depending on the activity of neuron in a particular moment, ASICs can differently modulate AP generation; they can induce, facilitate or inhibit APs. We also showed that trypsin changes the capability of ASICs to modulate AP generation by shifting the pH dependence to more acidic values, which adapts channel gating to pH conditions which may occur in pathological conditions such as ischemia. Our finding that trypsin modifies ASIC1 a function identifies a novel pharmacological tool, and proposes a mechanism of ASIC1a regulation that may have a physiological importance. The identification of the exact site of trypsin action gives insight to the molecular mechanisms of ASIC regulation. This work proposes a role in modulation of AP generation for ASICs in the CNS. RESUME Les canaux ASIC sont les canaux ioniques activés par l'acidification rapide extracellulaire. Activés, ils génèrent un courant entrant qui inactive en présence de stimulus acide. Quatre gènes ASIC ont été clonés, ASIC1, 2, 3 et 4, avec les variants a et b pour ASIC1 et 2. Les ASICs sont exprimés dans les neurones du système nerveux central (SNC) et périphérique (SNP). Dans le SNC, les ASIC ont un rôle dans le mémoire, apprentissage et la mort neuronale dans t'ischémie. Dans le SNP, ils ont un rôle dans la perception de la douleur et méchanosensation. Dans une partie de mon projet de thèse, nous avons étudié les mécanismes de la régulation d'ASIC1a par la sérine-protéase trypsine au niveau moléculaire. La trypsine modifie la fonction d'ASIC1a et pas ASIC1b. Nous avons créé les chimères entre ASIC1 a et 1 b, afin d'identifier la région du canal responsable pour l'effet. Pour identifier le(s) site(s) exactes de l'action de la trypsine, nous avons muté les sites potentiels de la trypsine dans la région identifiée par les chimères. Dans la deuxième partie du projet, nous avons étudié le rôle des ASICs au niveau cellulaire. En utilisant la technique du patch clamp dans les cultures des neurones de l'hippocampe, nous avons étudié l'implication des ASICs dans la génération des potentiels d'action (PA). Nous avons montré que la trypsine agit sur le canal ASIC1a ; elle décale l'activation et « steady-state » inactivation vers les valeurs plus acides, et elle raccourcit le temps du « recovery » du canal. La trypsine coupe ASIC1a sur le résidu K145 et l'effet fonctionnel et la coupure corrèlent. Nous avons identifié la région du canal responsable pour l'inactivation de tous les ASICs ; une partie de cette région est responsable pour ['inhibition d'ASIC1 a par la Psalmotoxinel . Nous avons montré que les ASICs peuvent moduler la génération des PAs. L'activité des ASICs peut induire les trains des PAs. Quand l'activité des ASICs n'est pas suffisante pour induire le PA, elle peut contribuer à sa génération. Pendant l'activité neuronale forte, l'activité des ASICs peut bloquer les trains des PAs qui existent déjà. En conclusion, dépendant de l'activité neuronale, les ASICs peuvent moduler la génération des PAs différemment ; ils peuvent induire, faciliter ou inhiber les PAs. La trypsine change la capacité des ASICs de moduler les PAs. Après l'action de la trypsine, les ASICs peuvent moduler la génération des PAs dans les conditions légèrement acides, suivies par les fluctuations du pH acide, qui peuvent exister dans l'ischémie. Le fait que la trypsine agit sur ASIC1a définit l'outil pharmacologique et propose le mécanisme de la régulation d'ASICI a qui pourrait avoir l'importance physiologique. L'identification du site de l'action de la trypsine éclaircit les mécanismes moléculaires de la régulation des ASICs. Cette étude propose un rôle des ASICs dans la modulation de la génération des PAs. Résumé pour le public large Les neurones sont les cellules de système nerveux dont la fonction est la signalisation. Comme toutes les autres cellules, les neurones ont une membrane qui sépare l'intérieur du milieu extérieur. Cette membrane est imperméable pour des particules chargées (ions). Dans cette membrane existent les protéines spécifiques, « canaux », qui permettent le transport des ions d'un côté de la membrane à l'autre, comme réponse aux stimuli différents. Ce transport des ions à travers la membrane génère un courant, qu'on peut mesurer. Ce courant est la base de la communication entre les neurones, ou, ce qu'on appelle la signalisation neuronale. Quand ce courant est suffisamment grand, il permet la génération du potentiel d'action, qui est le message principal de communication neuronale. Les canaux ASIC (acid-sensing ion channel), que nous étudions dans le laboratoire, sont activés par les acides. Les acides sont relâchés dans beaucoup de situations dans le système nerveux. Les ASIC ont été découverts récemment (en 1996), et nous ne connaissons pas encore très bien toutes les fonctions de ces canaux. Nous savons qu'ils ont un rôle dans le mémoire, apprentissage, la sensation de la douleur et l'infarctus cérébral. Dans la première partie de ce projet de thèse, nous avons voulu mieux comprendre comment fonctionnent ces canaux. Pour faire ça, nous avons étudié la régulation des ASICs par une protéine, trypsine, qui coupe le canal ASIC. Nous avons étudié ou exactement la trypsine coupe le canal et quels effets ça produit sur la fonction du canal. Dans la deuxième partie du projet de thèse, nous avons voulu mieux connaître comment le canal fonctionne au niveau de la cellule, comment il interagit avec les autres canaux et si il a un rôle dans la génération des potentiels d'action. Nous avons pu montrer que la trypsine change la fonction du canal, ce qui lui permet de fonctionner différemment. Nous avons aussi déterminé ou exactement ta trypsine coupe le canal. Au niveau de la cellule, nous avons montré que les ASIC peuvent moduler la génération des potentiels d'action, étant, dépendant de l'activité du neurone, soit activateurs, soit inhibiteurs. La trypsine est une molécule qui peut être libérée dans le système nerveux pendant certaines conditions, comme l'infarctus cérébral. A cause de ça, les connaissances que la trypsine agit sur le anal ASIC pourraient être important physiologiquement. La connaissance de l'endroit exacte ou la trypsine coupe le canal nous aide à mieux comprendre la relation structure-fonction du canal. La modulation de la génération des potentiels d'actions par les ASIC indique que ces canaux peuvent avoir un rôle important dans la signalisation neuronale.

Perception and Interpretation of Advance Warning Signs on County Roads, HR-256, 1984

This research consisted of five laboratory experiments designed to address the following two objectives in an integrated analysis: (1) To discriminate between the symbol Stop Ahead warning sign and a small set of other signs (which included the word-legend Stop Ahead sign); and (2) To analyze sign detection, recognizability, and processing characteristics by drivers. A set of 16 signs was used in each of three experiments. A tachistoscope was used to display each sign image to a respondent for a brief interval in a controlled viewing experiment. The first experiment was designed to test detection of a sign in the driver's visual field; the second experiment was designed to test the driver's ability to recognize a given sign in the visual field; and the third experiment was designed to test the speed and accuracy of a driver's response to each sign as a command to perform a driving action. A fourth experiment tested the meanings drivers associated with an eight-sign subset of the 16 signs used in the first three experiments. A fifth experiment required all persons to select which (if any) signs they considered to be appropriate for use on two scale model county road intersections. The conclusions are that word-legend Stop Ahead signs are more effective driver communication devices than symbol stop-ahead signs; that it is helpful to drivers to have a word plate supplementing the symbol sign if a symbol sign is used; and that the guidance in the Manual on Uniform Traffic Control Devices on the placement of advance warning signs should not supplant engineering judgment in providing proper sign communication at an intersection.

Recommendations for malaria prevention in moderate to low risk areas: travellers' choice and risk perception.

BACKGROUND: The considerable malaria decline in several countries challenges the strategy of chemoprophylaxis for travellers visiting moderate- to low-risk areas. An international consensus on the best strategy is lacking. It is essential to include travellers' opinions in the decision process. The preference of travellers regarding malaria prevention for moderate- to low-risk areas, related to their risk perception, as well as the reasons for their choices were investigated. METHODS: Prior to pre-travel consultation in the Travel Clinic, a self-administered questionnaire was given to travellers visiting moderate- to low-risk malaria areas. Four preventive options were proposed to the traveller, i.e., bite prevention only, chemoprophylaxis, stand-by emergency treatment alone, and stand-by emergency treatment with rapid diagnostic test. The information was accompanied by a risk scale for incidence of malaria, anti-malarial adverse drug reactions and other travel-related risks, inspired by Paling palettes from the Risk Communication Institute. RESULTS: A total of 391 travellers were included from December 2012 to December 2013. Fifty-nine (15%) opted for chemoprophylaxis, 116 (30%) for stand-by emergency treatment, 112 (29%) for stand-by emergency treatment with rapid diagnostic test, 100 (26%) for bite prevention only, and four (1%) for other choices. Travellers choosing chemoprophylaxis justified their choice for security reasons (42%), better preventive action (29%), higher efficacy (15%) and easiness (15%). The reasons for choosing stand-by treatment or bite prevention only were less medication consumed (29%), less adverse drug reactions (23%) and lower price (9%). Those who chose chemoprophylaxis were more likely to have used it in the past (OR = 3.0 (CI 1.7-5.44)), but were not different in terms of demographic, travel characteristics or risk behaviour. CONCLUSIONS: When travelling to moderate- to low-risk malaria areas, 85% of interviewees chose not to take chemoprophylaxis as malaria prevention, although most guidelines recommend it. They had coherent reasons for their choice. New recommendations should include shared decision-making to take into account travellers' preferences.

Recommandations for malaria prevention in moderate to low risk areas : traveller's choice and risk perception

Background. Le considérable déclin de la malaria au niveau mondial remet en question la stratégie de chimioprophylaxie pour les voyageurs à destination de pays à risque modéré à faible de malaria. Un consensus international de la meilleure stratégie de prévention reste à trouver. Suivant le mouvement actuel de partage décisionnel, cette étude invite le voyageur au sein du débat comme acteur du processus de décision. Objectifs. Investiguer les préférences des voyageurs à destination de pays à risque modéré à faible de malaria en matière de prévention contre la malaria, en mettant en perspective leur perception du risque et les raisons de leur choix. Méthodologie. Dans la salle d'attente du Centre de Vaccination et Médecine de Voyage, les voyageurs à destination de risque modéré à faible de malaria remplissent un questionnaire et choisissent la méthode de prévention qu'ils préfèrent aidés d'un tableau leur proposant 4 choix possible ; mesure de prévention des piqûres de moustique uniquement, chimioprophylaxie, traitement de réserve seul et traitement de réserve avec test diagnostic rapide. Ils reçoivent aussi une échelle de risque illustrant les risques de malaria et d'effets indésirables des anti-malariques comparés à différents autres risques liés au voyage, inspirée par les palettes de Paling de la Communication Risk Institut. Résultats. De décembre 2012 à décembre 2013, 391 voyageurs on été inclus. 59 (15%) ont choisi la chimioprophylaxie, 116 (30%) un traitement de réserve, 112 (29%) un traitement de réserve avec test rapide diagnostic, 100 (26%) une prévention des piqûre de moustiques uniquement, and 4 (1%) plusieurs alternatives. Les raisons de choisir une chimioprophylaxie étaient la sécurité (42%), l'action préventive (29%), l'efficacité (15%) et la facilité d'utilisation (15%). Les raisons de choisir un traitement de réserve étaient moins de prise de médicament (29%), moins d'effets secondaires de ceux-ci (23%) et le prix (9%). Les voyageurs choisissant la chimioprohylaxie l'avaient plus souvent déjà utilisée par le passé [OR=3.0 (CI 1.7-5.44)], sans différence en terme de profil démographique, caractéristique du voyage ou comportement à risque. Conclusions. Quand interrogés, 85% des voyageurs à destination de pays à risque modéré à faible de malaria préfèrent ne pas prendre la chimioprophylaxie, bien que la plupart des pays la recommande encore. Les raisons avancées sont cohérentes avec leur choix. Les nouvelles recommandations devraient prendre en compte la préférence des voyageurs et inclure un processus de décision partagé.

« On m'accuse de discrimination, moi ! » Tout est une histoire de perception

De nos jours, les comportements discriminatoires sont mal vus par la société. On tend à montrer du doigt les personnes s'engageant dans de tels comportements et à médiatiser les entreprises prises en flagrant délit de discrimination, tant au niveau du processus d'embauche (p. ex., rejet systématique des candidatures venant de candidats d'origine étrangère), qu'au niveau des différences de traitement au sein des entreprises (p. ex., différence de salaires entre les femmes et les hommes). Si les comportements discriminatoires sont si mal perçus, pourquoi sont-ils toujours d'actualité ? Comment est-ce que des personnes s'engageant dans de tels comportements peuvent garder à la fois une image positive d'eux-mêmes et éviter de se faire réprimander par d'autres personnes qui pourraient avoir connaissance de leurs mauvais agissements ? C'est à cette problématique que je m'atèle dans ma recherche. A travers une expérience sur le thème de la discrimination à l'embauche, je démontre que les individus ayant tendance à se désengager moralement de leur propre action sont plus à même de s'engager dans des comportements discriminatoires que les autres individus. Le désengagement moral est un processus par lequel les individus justifient leur propre comportement non-éthique afin de les rendre acceptable (Bandura, 1986). En particulier, les résultats ont révélé que cette relation entre désengagement moral et discrimination est modéré par le degré de préjugés des individus. Parmi les individus ayant des préjugés marqués envers les étrangers, plus leur tendance au désengagement moral est élevé, plus ils sont à même de s'engager dans des comportements discriminatoires.

Risk perception and stages of smoking acquisition = Percepción de riesgo y etapas de iniciación en el consumo de tabaco

The purpose of this descriptive survey was to investigate the risk perceptions of smoking in a sample of 1,510 Spanish adolescents(49.1% males; mean age = 14.03; SD = 1.28). In addition, the present research categorised adolescents into one of the fourstages of smoking acquisition, as described by the Transtheoretical Model of Change (TMC): Precontemplation (notthinking about trying smoking in the next 6 months), Contemplation (thinking about trying smoking in the next 6 months), Preparation (thinking about starting smoking in the next 30 days) and Action (smokers), by gender and age. The results showed that age and risk perceptions are important variables in the progression through the stages of change towards regular tobacco consumption (Action stage). These results clearly demonstrate the importance of starting antismoking campaigns at an early age to prevent smoking acquisition or the thought of starting in the near future. These findings also highlight the need to continuously remind adolescents about the negative consequences of smoking