933 resultados para Cognitive Enhancement


Relevância:

60.00% 60.00%

Publicador:

Resumo:

The main thesis to be demonstrated in this work is that cognitive enhancement through the use of drugs can be included as a primary good within Rawls' thinking. To develop such notion, the text is structured in two parts. The first part intends to describe the theory of justice as equity in its elements directly related to primary goods. The first information to be verified is the unity of the notion of primary goods in all of Rawls' work. Some elements are modified, for example the distinction of natural and social primary goods. Natural primary goods are intelligence, health, imagination, vigor and chance (luck) and social primary goods are law and liberty, opportunity and power, income and wealth and the social fundaments of self-respect. The perception of some talents such as intelligence has also undergone changes, being altered from "higher intelligence" to "educated intelligence". Such fact highlights education as a primary good that permeates all of Rawls' work in different perspectives. Freedom and self-respect are social-primary goods that will also be deepened. The second part presents the definition of improvement and as to show that the distinction between enhancement and treatment is controversial. The part presents the definition of improvement and as the distinction between enhancement and treatment is controversial. Thus, we have deepened the problems related to practice improvement (enhancement) showing how the concepts of Rawls' primary goods as freedom and self-respect are not in opposition to the practice of improvement, particularly cognitive enhancement. We have shown, instead, that the ban of cognitive improvement could lead to denial of these primary goods. But how could we consider cognitive improvement as a primary social good? What we have done in this thesis is to show how cognitive enhancement is important to ensure that primary products are accessible to citizens, and we rebuilt the process that Rawls uses for choosing his primary goods to test that cognitive enhancement through drugs could perfectly be introduced as such.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The main thesis to be demonstrated in this work is that cognitive enhancement through the use of drugs can be included as a primary good within Rawls' thinking. To develop such notion, the text is structured in two parts. The first part intends to describe the theory of justice as equity in its elements directly related to primary goods. The first information to be verified is the unity of the notion of primary goods in all of Rawls' work. Some elements are modified, for example the distinction of natural and social primary goods. Natural primary goods are intelligence, health, imagination, vigor and chance (luck) and social primary goods are law and liberty, opportunity and power, income and wealth and the social fundaments of self-respect. The perception of some talents such as intelligence has also undergone changes, being altered from "higher intelligence" to "educated intelligence". Such fact highlights education as a primary good that permeates all of Rawls' work in different perspectives. Freedom and self-respect are social-primary goods that will also be deepened. The second part presents the definition of improvement and as to show that the distinction between enhancement and treatment is controversial. The part presents the definition of improvement and as the distinction between enhancement and treatment is controversial. Thus, we have deepened the problems related to practice improvement (enhancement) showing how the concepts of Rawls' primary goods as freedom and self-respect are not in opposition to the practice of improvement, particularly cognitive enhancement. We have shown, instead, that the ban of cognitive improvement could lead to denial of these primary goods. But how could we consider cognitive improvement as a primary social good? What we have done in this thesis is to show how cognitive enhancement is important to ensure that primary products are accessible to citizens, and we rebuilt the process that Rawls uses for choosing his primary goods to test that cognitive enhancement through drugs could perfectly be introduced as such.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Glutamate was previously shown to enhance aerobic glycolysis i.e. increase glucose utilization and lactate production with no change in oxygen levels, in mouse cortical astrocytes by a mechanism involving glutamate uptake. It is reported here that a similar response is produced in both hippocampal and cerebellar astrocytes. Application of the cognitive-enhancing drug CX546 promoted further enhancement of glucose utilization by astrocytes from each brain area following glutamate exposure. alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors represent the purported molecular target of cognitive-enhancing drugs such as CX546, and the presence of AMPA receptor subunits GluR1-4 was evidenced in astrocytes from all three regions by immunocytochemistry. AMPA itself did not stimulate aerobic glycolysis, but in the presence of CX546, a strong enhancement of glucose utilization and lactate production was obtained in cortical, hippocampal and cerebellar astrocytes. The effect of CX546 was concentration-dependent, with an EC(50) of 93.2 microm in cortical astrocytes. AMPA-induced glucose utilization in the presence of CX546 was prevented by the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and the negative modulator GYKI 52466. In addition, the metabolic effect of CX546 in the presence of AMPA was mimicked by the AMPA receptor modulator cyclothiazide. Our data suggest that astrocyte energetics represents a novel target for cognitive-enhancing drugs acting as AMPA receptor modulators.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A brief intervention using motivational and cognitive behavioural approaches to help change drug use. Also offer alternative brief interventions for clients not suited to the current approach. This manual is divided into five sections: Section 1. Context Key points from the National Drug Strategy Monograph No 51. Models of Intervention and Care for Psychostimulant Users are included to present the evidence supporting this type of intervention for regular amphetamine users.  A flow-chart to place the intervention in a treatment context. Section 2. Brief background to the study and summary of results of evaluation A brief description of how the study was developed, undertaken and evaluated. A brief description of the evaluation outcome data (detailed results will be published separately). Section 3. The intervention The CBT intervention is presented in a clear and easy to use format for practitioners. Section 4. Suggested alternative brief interventions for those not suitable for the current intervention This section provides an overview of recommendations for alternative interventions for psychostimulant users who are unsuitable for the CBT intervention (e.g. those who are not considering change, experimental users etc). Section 5. Other available resources This section lists a range of other resources that are currently available for practitioners working with psychostimulant users. This treatment guide has not been designed to stand alone. Rather, practitioners are encouraged to: 1. Acquaint themselves with the current research and clinical literature. The recently completed monograph Models of Intervention and Care for Psychostimulant Users is an excellent resource for current evidence supporting practice in this area. 2. Undertake training in CBT and motivational enhancement techniques if unfamiliar with these approaches. 3. Obtain ongoing clinical supervision.This resource was contributed by The National Documentation Centre on Drug Use.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Approaching or looming sounds (L-sounds) have been shown to selectively increase visual cortex excitability [Romei, V., Murray, M. M., Cappe, C., & Thut, G. Preperceptual and stimulus-selective enhancement of low-level human visual cortex excitability by sounds. Current Biology, 19, 1799-1805, 2009]. These cross-modal effects start at an early, preperceptual stage of sound processing and persist with increasing sound duration. Here, we identified individual factors contributing to cross-modal effects on visual cortex excitability and studied the persistence of effects after sound offset. To this end, we probed the impact of different L-sound velocities on phosphene perception postsound as a function of individual auditory versus visual preference/dominance using single-pulse TMS over the occipital pole. We found that the boosting of phosphene perception by L-sounds continued for several tens of milliseconds after the end of the L-sound and was temporally sensitive to different L-sound profiles (velocities). In addition, we found that this depended on an individual's preferred sensory modality (auditory vs. visual) as determined through a divided attention task (attentional preference), but not on their simple threshold detection level per sensory modality. Whereas individuals with "visual preference" showed enhanced phosphene perception irrespective of L-sound velocity, those with "auditory preference" showed differential peaks in phosphene perception whose delays after sound-offset followed the different L-sound velocity profiles. These novel findings suggest that looming signals modulate visual cortex excitability beyond sound duration possibly to support prompt identification and reaction to potentially dangerous approaching objects. The observed interindividual differences favor the idea that unlike early effects this late L-sound impact on visual cortex excitability is influenced by cross-modal attentional mechanisms rather than low-level sensory processes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Réalisée en cotutelle avec l'Unité de Formation à la Recherche Lettres Arts et Sciences Humaines - Université Nice-Sophia Antipolis.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

L’estime de soi joue un rôle central lorsqu’il est question de prédire les réactions des individus au feedback. En dépit de son influence indéniable sur les réactions des individus au feedback en contexte d’évaluation de potentiel, peu d’études se sont attardées aux facteurs pouvant en atténuer l’effet dans le cadre d’une telle démarche. Cette thèse vise à combler ce manque à travers deux articles empiriques répondant chacun à plusieurs objectifs de recherche. Dans cette optique, des données ont été amassées auprès de deux échantillons indépendants de candidats (étude 1, N = 111; étude 2, N = 153) ayant réalisé une évaluation de potentiel dans une firme-conseil spécialisée en psychologie industrielle. Le premier article vise à tester deux théories relatives à l’estime de soi s’affrontant lorsqu’il est question de prédire les réactions cognitives au feedback, la théorie de l’auto-valorisation et de l’auto-vérification. Pour mieux comprendre ce phénomène, l’influence de l’estime de soi et de la valence décisionnelle du feedback sur les deux composantes de l’appropriation cognitive du feedback en contexte d’évaluation, l’acceptation et la conscientisation, a été testé. Les résultats soutiennent les postulats de la théorie d’auto-valorisation lorsqu’il est question de prédire l’acceptation du feedback. En contrepartie, les résultats offrent peu de soutien à la théorie de l’auto-vérification dans la prédiction de la conscientisation à l’égard du feedback. Le second article vise à identifier des leviers modulables pour influencer favorablement les réactions des individus ayant une plus faible estime d’eux-mêmes. Pour ce faire, deux variables relatives à l’influence de la source ont été ciblées, la crédibilité perçue et les pratiques de confrontation constructive. Cet article comprend deux études, soit une première ayant pour objectif de valider un instrument mesurant la crédibilité perçue de la source et une seconde examinant les relations entre trois déterminants, soit l’estime de soi du candidat, la crédibilité perçue de la source et les pratiques de confrontation constructive, et deux réactions cognitives au feedback, l’acceptation et la conscientisation. Les analyses de la première étude font ressortir que l’échelle de crédibilité perçue présente des qualités psychométriques satisfaisantes et les résultats corroborent une structure unifactorielle. Les résultats de la seconde étude indiquent que les trois déterminants étudiés sont positivement reliés à l’acceptation et à la conscientisation. Les effets d’interaction significatifs font ressortir des conditions favorisant l’acceptation et la conscientisation chez les individus ayant une plus faible estime d’eux-mêmes. La crédibilité perçue atténue la relation entre l’estime de soi et l’acceptation alors que la confrontation constructive modère les relations entre l’estime de soi et, tant l’acceptation que la conscientisation. Enfin, la crédibilité perçue et la confrontation constructive interagissent dans la prédiction de la conscientisation, faisant ainsi ressortir l’importance d’établir sa crédibilité pour augmenter l’effet positif de la confrontation constructive. Les apports théorique et conceptuel de chacun des articles ainsi que les pistes d’intervention pratiques en découlant sont discutés séparément et repris dans une conclusion globale. Les retombées de cette thèse, tant sur le plan de la recherche que de l'intervention, sont également abordées dans cette dernière section.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The research activity carried out during the PhD course was focused on the development of mathematical models of some cognitive processes and their validation by means of data present in literature, with a double aim: i) to achieve a better interpretation and explanation of the great amount of data obtained on these processes from different methodologies (electrophysiological recordings on animals, neuropsychological, psychophysical and neuroimaging studies in humans), ii) to exploit model predictions and results to guide future research and experiments. In particular, the research activity has been focused on two different projects: 1) the first one concerns the development of neural oscillators networks, in order to investigate the mechanisms of synchronization of the neural oscillatory activity during cognitive processes, such as object recognition, memory, language, attention; 2) the second one concerns the mathematical modelling of multisensory integration processes (e.g. visual-acoustic), which occur in several cortical and subcortical regions (in particular in a subcortical structure named Superior Colliculus (SC)), and which are fundamental for orienting motor and attentive responses to external world stimuli. This activity has been realized in collaboration with the Center for Studies and Researches in Cognitive Neuroscience of the University of Bologna (in Cesena) and the Department of Neurobiology and Anatomy of the Wake Forest University School of Medicine (NC, USA). PART 1. Objects representation in a number of cognitive functions, like perception and recognition, foresees distribute processes in different cortical areas. One of the main neurophysiological question concerns how the correlation between these disparate areas is realized, in order to succeed in grouping together the characteristics of the same object (binding problem) and in maintaining segregated the properties belonging to different objects simultaneously present (segmentation problem). Different theories have been proposed to address these questions (Barlow, 1972). One of the most influential theory is the so called “assembly coding”, postulated by Singer (2003), according to which 1) an object is well described by a few fundamental properties, processing in different and distributed cortical areas; 2) the recognition of the object would be realized by means of the simultaneously activation of the cortical areas representing its different features; 3) groups of properties belonging to different objects would be kept separated in the time domain. In Chapter 1.1 and in Chapter 1.2 we present two neural network models for object recognition, based on the “assembly coding” hypothesis. These models are networks of Wilson-Cowan oscillators which exploit: i) two high-level “Gestalt Rules” (the similarity and previous knowledge rules), to realize the functional link between elements of different cortical areas representing properties of the same object (binding problem); 2) the synchronization of the neural oscillatory activity in the γ-band (30-100Hz), to segregate in time the representations of different objects simultaneously present (segmentation problem). These models are able to recognize and reconstruct multiple simultaneous external objects, even in difficult case (some wrong or lacking features, shared features, superimposed noise). In Chapter 1.3 the previous models are extended to realize a semantic memory, in which sensory-motor representations of objects are linked with words. To this aim, the network, previously developed, devoted to the representation of objects as a collection of sensory-motor features, is reciprocally linked with a second network devoted to the representation of words (lexical network) Synapses linking the two networks are trained via a time-dependent Hebbian rule, during a training period in which individual objects are presented together with the corresponding words. Simulation results demonstrate that, during the retrieval phase, the network can deal with the simultaneous presence of objects (from sensory-motor inputs) and words (from linguistic inputs), can correctly associate objects with words and segment objects even in the presence of incomplete information. Moreover, the network can realize some semantic links among words representing objects with some shared features. These results support the idea that semantic memory can be described as an integrated process, whose content is retrieved by the co-activation of different multimodal regions. In perspective, extended versions of this model may be used to test conceptual theories, and to provide a quantitative assessment of existing data (for instance concerning patients with neural deficits). PART 2. The ability of the brain to integrate information from different sensory channels is fundamental to perception of the external world (Stein et al, 1993). It is well documented that a number of extraprimary areas have neurons capable of such a task; one of the best known of these is the superior colliculus (SC). This midbrain structure receives auditory, visual and somatosensory inputs from different subcortical and cortical areas, and is involved in the control of orientation to external events (Wallace et al, 1993). SC neurons respond to each of these sensory inputs separately, but is also capable of integrating them (Stein et al, 1993) so that the response to the combined multisensory stimuli is greater than that to the individual component stimuli (enhancement). This enhancement is proportionately greater if the modality-specific paired stimuli are weaker (the principle of inverse effectiveness). Several studies have shown that the capability of SC neurons to engage in multisensory integration requires inputs from cortex; primarily the anterior ectosylvian sulcus (AES), but also the rostral lateral suprasylvian sulcus (rLS). If these cortical inputs are deactivated the response of SC neurons to cross-modal stimulation is no different from that evoked by the most effective of its individual component stimuli (Jiang et al 2001). This phenomenon can be better understood through mathematical models. The use of mathematical models and neural networks can place the mass of data that has been accumulated about this phenomenon and its underlying circuitry into a coherent theoretical structure. In Chapter 2.1 a simple neural network model of this structure is presented; this model is able to reproduce a large number of SC behaviours like multisensory enhancement, multisensory and unisensory depression, inverse effectiveness. In Chapter 2.2 this model was improved by incorporating more neurophysiological knowledge about the neural circuitry underlying SC multisensory integration, in order to suggest possible physiological mechanisms through which it is effected. This endeavour was realized in collaboration with Professor B.E. Stein and Doctor B. Rowland during the 6 months-period spent at the Department of Neurobiology and Anatomy of the Wake Forest University School of Medicine (NC, USA), within the Marco Polo Project. The model includes four distinct unisensory areas that are devoted to a topological representation of external stimuli. Two of them represent subregions of the AES (i.e., FAES, an auditory area, and AEV, a visual area) and send descending inputs to the ipsilateral SC; the other two represent subcortical areas (one auditory and one visual) projecting ascending inputs to the same SC. Different competitive mechanisms, realized by means of population of interneurons, are used in the model to reproduce the different behaviour of SC neurons in conditions of cortical activation and deactivation. The model, with a single set of parameters, is able to mimic the behaviour of SC multisensory neurons in response to very different stimulus conditions (multisensory enhancement, inverse effectiveness, within- and cross-modal suppression of spatially disparate stimuli), with cortex functional and cortex deactivated, and with a particular type of membrane receptors (NMDA receptors) active or inhibited. All these results agree with the data reported in Jiang et al. (2001) and in Binns and Salt (1996). The model suggests that non-linearities in neural responses and synaptic (excitatory and inhibitory) connections can explain the fundamental aspects of multisensory integration, and provides a biologically plausible hypothesis about the underlying circuitry.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A software prototype for dynamic route planning in the travel industry for cognitive cities is presented in this paper. In contrast to existing tools, the prototype enhances the travel experience (i.e., sightseeing) by allowing additional flexibility to the user. The theoretical background of the paper strengthens the understanding of the introduced concepts (e.g., cognitive cities, fuzzy logic, graph databases) to comprehend the presented prototype. The prototype applies an instantiation and enhancement of the graph database Neo4j . For didactical reasons and to strengthen the understanding of this prototype a scenario, applied to route planning in the city of Bern (Switzerland) is shown in the paper.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This dissertation reports an investigation of the utility of two intervention programs to facilitate identity formation by way of exploration, one designed from an explicitly self-construction point of view and the other designed from an explicitly self-discovery point of view. The self-construction program was implemented using cognitive skills and orientations derived from Berzonsky (1989), Grotevant (1987), and Kurtines (1999). The self-discovery program was implemented using affective insight development strategies derived from Csikszentmihalyi (1990), Maslow (1968), and Waterman (1990). Three sets of measures were used: (a) cognitive identity measures, (b) affective identity measures, and (c) overall identity measures. Ninety undergraduates from Florida International University completed the intervention. Participants were assigned to one of three intervention conditions (Cognitive, Affective, and Control) and were pretested and posttested on cognitive, affective, and overall identity measures. Intervention strategies were introduced and discussed in the context of specific goals and choices that participants brought to group. Intervention results were then analyzed in terms of the effectiveness of the intervention conditions in promoting their respective developmental domains. The intervention was effective in promoting identity development in comparison to the control condition, with the cognitive condition facilitating cognitive competence and the affective condition facilitating affective insight. Results are discussed in the context of the constructivist and discovery perspectives, as well as in light of the broadened view of exploration offered in this paper. ^

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study analyzed outcomes of an enhanced cognitive-behavioral intervention with dually diagnosed severely mentally ill adults. It specifically addressed the improvement of attitudes, skills, self-efficacy to use condoms and the heightening of condom use. The data were analyzed via a randomized three-group repeated measures design composed of the experimental (E-CB), standard care (SC) comparison or a no-treatment control condition as the between-subjects variable and pre-post measure as the within-subjects variable. The E-CB focused on cooperative, application, hands-on, skill-building and role-playing activities for sexual assertiveness, negotiation in risk-taking and proper condom use. The SC comparison, was didactic in its approach and addressed risk-taking and proper condom use in one session, but did not involve application approaches to problem-solving risky situations or condom use. Multiple assessments were conducted at pre-, post- and six months post-intervention. ^ The analysis indicated that the E-CB intervention led to more favorable attitudes toward condoms and to improved and maintained skills regarding their use by participants six months after the intervention compared to the standard care and control groups. No significant improvements in self-efficacy were found. A repeated measures ANOVA conducted on the transformed values of percentage of vaginal condom use indicated no significant differences between the experimental and standard care conditions but both had a significantly higher mean percentage vaginal condom use than the control group, averaged across pre- and six-month post-intervention. No gender differences were seen in attitudes, skills or self-efficacy to use condoms. ^ This study shed light upon the effectiveness of the instructional approach for the enhancement of attitudes, skills and self-efficacy outcomes related to HIV prevention. For heightened effectiveness, future approaches must address multiple factors impacting learning in this population. ^

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Speech perception routinely takes place in noisy or degraded listening environments, leading to ambiguity in the identity of the speech token. Here, I present one review paper and two experimental papers that highlight cognitive and visual speech contributions to the listening process, particularly in challenging listening environments. First, I survey the literature linking audiometric age-related hearing loss and cognitive decline and review the four proposed causal mechanisms underlying this link. I argue that future research in this area requires greater consideration of the functional overlap between hearing and cognition. I also present an alternative framework for understanding causal relationships between age-related declines in hearing and cognition, with emphasis on the interconnected nature of hearing and cognition and likely contributions from multiple causal mechanisms. I also provide a number of testable hypotheses to examine how impairments in one domain may affect the other. In my first experimental study, I examine the direct contribution of working memory (through a cognitive training manipulation) on speech in noise comprehension in older adults. My results challenge the efficacy of cognitive training more generally, and also provide support for the contribution of sentence context in reducing working memory load. My findings also challenge the ubiquitous use of the Reading Span test as a pure test of working memory. In a second experimental (fMRI) study, I examine the role of attention in audiovisual speech integration, particularly when the acoustic signal is degraded. I demonstrate that attentional processes support audiovisual speech integration in the middle and superior temporal gyri, as well as the fusiform gyrus. My results also suggest that the superior temporal sulcus is sensitive to intelligibility enhancement, regardless of how this benefit is obtained (i.e., whether it is obtained through visual speech information or speech clarity). In addition, I also demonstrate that both the cingulo-opercular network and motor speech areas are recruited in difficult listening conditions. Taken together, these findings augment our understanding of cognitive contributions to the listening process and demonstrate that memory, working memory, and executive control networks may flexibly be recruited in order to meet listening demands in challenging environments.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

It is well known that self-generated stimuli are processed differently from externally generated stimuli. For example, many people have noticed since childhood that it is very difficult to make a self-tickling. In the auditory domain, self-generated sounds elicit smaller brain responses as compared to externally generated sounds, known as the sensory attenuation (SA) effect. SA is manifested in reduced amplitudes of evoked responses as measured through MEEG, decreased firing rates of neurons and a lower level of perceived loudness for self-generated sounds. The predominant explanation for SA is based on the idea that self-generated stimuli are predicted (e.g., the forward model account). It is the nature of their predictability that is crucial for SA. On the contrary, the sensory gating account emphasizes a general suppressive effect of actions on sensory processing, regardless of the predictability of the stimuli. Both accounts have received empirical support, which suggests that both mechanisms may exist. In chapter 2, three behavioural studies concerning the influence of motor activation on auditory perception were presented. Study 1 compared the effect of SA and attention in an auditory detection task and showed that SA was present even when substantial attention was paid to unpredictable stimuli. Study 2 compared the loudness perception of tones generated by others between Chinese and British participants. Compared to externally generated tones, a decrease in perceived loudness for others generated tones was found among Chinese but not among the British. In study 3, partial evidence was found that even when reading words that are related to action, auditory detection performance was impaired. In chapter 3, the classic SA effect of M100 suppression was replicated with MEG in study 4. With time-frequency analysis, a potential neural information processing sequence was found in auditory cortex. Prior to the onset of self-generated tones, there was an increase of oscillatory power in the alpha band. After the stimulus onset, reduced gamma power and alpha/beta phase locking were found. The three temporally segregated oscillatory events correlated with each other and with SA effect, which may be the underlying neural implementation of SA. In chapter 4, a TMS-MEG study was presented investigating the role of the cerebellum in adapting to delayed presentation of self-generated tones (study 5). It demonstrated that in sham stimulation condition, the brain can adapt to the delay (about 100 ms) within 300 trials of learning by showing a significant increase of SA effect in the suppression of M100, but not M200 component. Whereas after stimulating the cerebellum with a suppressive TMS protocol, the adaptation in M100 suppression disappeared and the pattern of M200 suppression reversed to M200 enhancement. These data support the idea that the suppressive effect of actions on auditory processing is a consequence of both motor driven sensory predictions and general sensory gating. The results also demonstrate the importance of neural oscillations in implementing SA effect and the critical role of the cerebellum in learning sensory predictions under sensory perturbation.