This thesis describes a series of empirical studies about perceptions of trustworthiness and trusting behaviour. My first three studies investigate how perceptions of trustworthiness are related to both general preferences for sexually dimorphic face characteristics and individual differences in these preferences. My first study (Chapter 2) provided evidence against a simplistic 'halo-effect' view of the relationship between attractiveness and trustworthiness. The next two studies (Chapters 3 and 4) clarified the role of perceptions of trustworthiness in individual differences in women’s preferences for sexually dimorphic cues in men’s faces; while perceptions of trustworthiness did not explain condition-dependent individual differences (Chapter 3), they were implicated in temporal context-dependent preferences, such as when women assessed men’s attractiveness for long-term relationships (Chapter 4). My next two studies examined perceptions of trustworthiness in different contexts. The first of these studies demonstrated that different individuals are more likely to be trusted according to the type of information that they are conveying (Chapter 5); men are more likely to be trusted when delivering male-stereotyped information and women are more likely to be trusted when delivering female-stereotyped information. The last of my studies (Chapter 6) demonstrated how own appearance affects trusting behaviour in an economic game; the extent to which participants trusted game partners who could see them more than game partners who could not see them was positively related to their other-rated attractiveness. Collectively, the findings reported in this thesis demonstrate the relationship between perceptions of attractiveness and perceptions of trustworthiness, highlighting the complexity and sophistication of the perception of these fundamental social characteristics.

Emotion theories posit that emotion systems (e.g., behavior, self-report, physiology) should be related when an emotion is being elicited because this serves an adaptive purpose and allows the individual to respond appropriately to the present situation. Oftentimes, this coherent relationship is not found, and research has hypothesized that the type of analyses used and lack of examination of individual differences could be affecting this relationship. Most studies examine the relationship between emotion systems between-subjects when within-subjects analyses may be more appropriate. The present study examined the relationship between self-reported distress (SUDS) and heart rate, and whether trait differences of anxiety sensitivity and heart rate variability affect that relationship. Undergraduate students (N = 294) completed an anxiety sensitivity measure and their heart rate variability was calculated prior to undergoing a 7.5% CO2 challenge. SUDS was collected 11 times throughout the challenge and heart rate was collected continuously. Consistent with studies examining both concordance (between-subjects correlation between systems) and synchrony (within-subjects correlation between systems), synchrony was found between heart rate and SUDS, but concordance was not found between the two variables. Contrary to our hypotheses, neither anxiety sensitivity nor heart rate variability predicted synchrony between heart rate and SUDS. Our results suggest that synchrony is a more appropriate measure of adaptive emotional response than concordance because synchrony allows for examination of coordination of emotion systems over time.

Spatial ability is the skill associated with mental relations among objects, the process of maintaining the physical aspects of an object after mentally rotating it in space. Many studies report a strong association of spatial ability with success in various areas of health care, especially surgery, radiology and dentistry. To date, similar investigations in professional nursing could not be located. Registered nurses, employed in an acute care multi-hospital setting, were surveyed using the Shipley-2Block Pattern Test, the Group Embedded Figures Test, and a newly created test of general nursing knowledge. The sample size of 123 nurses was composed of 31 male nurses and 92 female nurses. Data was collected between May and August of 2013 and analyzed using R, version 2.15.2. The present study did not demonstrate a statistically significant effect for gender differences on two measures of spatial ability. However, Cohen’s d effect sizes for mean gender differences in the present study are consistent with prior studies. This may suggest the nursing profession is comparable with other professions where males perform higher than females on spatial ability. The present study should be considered an initial step toward evaluating the relevance of spatial ability in the performance of nursing care.

Le tabagisme est la cause de longues maladies, responsables chaque année de 6 millions de décès. Le principal composant du tabac, la nicotine, est l'un des psychotropes les plus addictifs. L’abandon du tabac est difficile et les pharmacothérapies les plus efficaces, telles que la varénicline, ne viennent en aide qu’à une proportion limitée des 70% de fumeurs qui souhaitent stopper. Des études cliniques et précliniques ont démontré que plusieurs mécanismes psychopharmacologiques différents contribuent au maintien de la prise de nicotine. Des données psychologiques, génétiques et neurobiologiques, issues d’études cliniques, indiquent désormais que le poids respectif de ces mécanismes psychopharmacologiques pourrait varier d’un fumeur à l’autre. Cette hétérogénéité pourrait contribuer à l’inégale efficacité de la varénicline, dont les cibles psychopharmacologiques sont encore mal connues, ainsi qu’à la faible validité prédictive des modèles précliniques, qui ne tiennent pas compte de cette possible hétérogénéité individuelle. Dans ce travail de thèse, au moyen de l’auto-administration intraveineuse de nicotine chez le rat, nous avons exploré les variations individuelles dans la sensibilité aux effets renforçants primaires de la nicotine et aux effets de la nicotine sur la sensibilité aux effets renforçants de stimuli environnementaux associés. Nous avons mis en évidence trois sous-populations d'individus dont la recherche de nicotine est contrôlée par une contribution différente de ces deux types d’effets de la nicotine. Les phénotypes de ces sous-populations ont été validés par des marqueurs comportementaux préexistants à la consommation de nicotine (l’approche conditionnée pavlovienne), par des marqueurs du métabolisme de la nicotine et des marqueurs neurobiologiques des neurotransmissions cholinergique et dopaminergique dans des structures cérébrales clés. En parallèle, nous avons exploré les cibles psychopharmacologiques de la varénicline. En utilisant une nouvelle approche qui permet de manipuler, pendant l’autoadministration, les effets de la nicotine sur les effets renforçants d’un stimulus environnemental associé, nous avons montré que la varénicline antagonise à la fois ces effets de la nicotine et ses effets renforçants primaires. Néanmoins, dans le premier cas, la varénicline agit d’autant plus que la sensibilité individuelle aux effets de la nicotine est élevée, alors que l’intensité de son effet ne dépend pas de l’amplitude des effets renforçants primaires de la nicotine. Ce travail de thèse met en évidence et valide des variations individuelles dans les mécanismes qui régissent le comportement de recherche de nicotine dans un modèle préclinique. Il offre pour perspective d'explorer les mécanismes neurobiologiques responsables de ces variations individuelles et l’impact à long terme de ces variations sur le développement de la dépendance à la nicotine, ainsi que de tester si la varénicline est plus efficace chez l’une des sous-populations identifiées. / Tobacco use leads to 6 million deaths every year due to severe long lasting diseases. The main component of tobacco, nicotine, is recognized as one of the most addictive drugs, making smoking cessation difficult, even when 70% of smokers wish to do so. Critically, even the most effective pharmacotherapies for smoking cessation, such as varenicline, have only limited efficacy. Clinical and preclinical studies have demonstrated consistently that nicotine seeking is a complex behavior involving various psychopharmacological mechanisms. Critically, converging psychological, genetic and neurobiological data from clinical studies support that the mechanisms controlling nicotine seeking may vary from individual to individual. This heterogeneity could explain the unequal efficiency of treatments, notably of varenicline, whose psychopharmacological targets are still poorly understood, and the poor predictive validity of preclinical models, which do not consider possible individual variations in the mechanisms of nicotine seeking. In this PhD work, using intravenous nicotine self-administration in the rat, we have explored individual variations in the control of nicotine seeking, by the primary reinforcing effects of nicotine, nicotine’s impact on environmental cues, or both. We have evidenced three sub-populations of individuals whose nicotine seeking is controlled by distinct contributions of nicotine primary reinforcing effects and nicotine-cue interactions. Their phenotypes of nicotine seeking have been supported and validated by pre-existing behavioral markers of Pavlovian conditioned approach, as well as by markers of nicotine metabolism, and neurobiological markers of cholinergic and dopamine transmissions in key brain structures. In parallel, we have explored psychopharmacological targets of varenicline. Using a novel approach that allows manipulating the reinforcing-enhancing effects of nicotine on cues, during nicotine self-administration, we evidenced that varenicline antagonizes both these cue reinforcing-enhancing effects and the primary reinforcing effect of nicotine, but as a function of the individual response amplitude for the former, and not for the latter. This PhD work evidences and validates preclinical individual variations in the mechanisms of nicotine seeking. It opens the perspective of exploring the neurobiological causal mechanisms for these individual variations, their long term impact on the development of nicotine dependence and whether varenicline efficacy benefits more to the subpopulation mostly driven by nicotine-induced enhancement of cue reinforcing effects.

A hipnose é um conjunto de técnicas usadas para provocar alterações nas percepções, sentimentos e experiências subjetivas de indivíduos, e tem uma história profundamente ligada ao desenvolvimento do campo da psicoterapia. Os fenômenos relacionados a este tema, tanto no campo da pesquisa quanto da clínica são complexos e envolvem influências sociais e diferenças individuais, em controvérsias ainda não sanadas pelos pesquisadores deste campo. Dentre as diferenças individuais salientamos a Hipnotizabilidade como um construto psicológico que descreve a capacidade dos sujeitos responderem à sugestão hipnótica, sendo a avaliação desta um elemento relevante para a correta interpretação das pesquisas experimentais, e para a compreensão de certos fenômenos da clínica psicológica. É digno de nota que a produção acadêmica internacional progride no estudo da hipnose, enquanto no Brasil temos ainda poucos trabalhos. Muitas razões podem ser atribuídas a esse descompasso, e dentre elas detectamos a falta de instrumentos padronizados de avaliação da hipnotizabilidade como um impedimento da realização de tais pesquisas. Assim, esta pesquisa teve como objetivo disponibilizar, em língua portuguesa, duas escalas de avaliação, a Harvard Group Scale of Hypnotic Susceptibility: form A e a Stanford Scale of Hypnotic Susceptibility: form C. Para isso as escalas foram traduzidas e adaptadas para o português brasileiro. Incluímos uma discussão sobre o procedimento de tradução de instrumentos dessa natureza, e como direcionamentos futuros sugerimos estudos de validação e normatização dessas escalas para a população brasileira / Hypnosis is a set of techniques used to provoke changes in an individuals perceptions, feelings and subjective experiences, and has a history deeply linked to the development of the psychotherapy field. The phenomena related to this theme, both in research and clinical fields, are complex and involve social influences and individual differences, in controversies not yet solved by the fields researchers. Among the individual differences we point Hypnotizability as a psychological construct that describes a subjects capacity to respond to hypnotic suggestion, which assessment is relevant to the correct evaluation of experimental research and the comprehension of certain clinical phenomena in psychology. It is of note that the international academic production advance in the study of hypnosis, while in Brazil we still have few studies. Many reasons can be attributed to this, and among them we detect the lack of standardized hypnotizability assessment instruments as a hindrance in making such research. So this research had the objective to make two assessment scales available in portuguese, namely the Harvard Group Scale of Hypnotic Susceptibility: Form A and the Stanford Scale of Hypnotic Susceptibility: Form C. To this end the scales we translated and adapted to the brazilian portuguese language. We include a discussion about the procedure of translation of instruments such as these, e as future developments we suggest validation and normatization studies of these scales to the brazilian population

Video games are played by more than 1.8 billion people and are a pervasive force in society, but despite decades of research there has been little consensus on their effects. Before we are able to model complex outcomes such as excessive engagement, we must first understand how and why people play video games. This dissertation integrates latent factor models with techniques from machine learning and network analysis to develop a holistic picture of gaming style, motivations, and individual differences. It employs diverse sources of data across several studies and a total of 2,143 participants, combining online questionnaires with qualitative analysis of participant responses and objective information about gaming behaviour from the API of the popular gaming network "Steam", and finds that stress relief is a primary motivation for engaging in the immersive worlds of video games. Previous research has indicated three underlying factors of Immersion, Achievement and Socialising which replicated across three comprehensive studies of 480 adults, 106 adults and children with an Autism Spectrum Condition, and 961 adults and adolescents. Gamers experiencing more stress in their daily lives were more likely to have Immersion rather than Social or Achievement play styles. Achievement-oriented gamers tended to be lower in stress, higher in conscientiousness and emotional stability, and played more than Immersion-focused gamers. A qualitative analysis of 54 gamers' descriptions of why they recently chose to play a game was used to develop the "Reasons for Playing Video Games" items (RPVG), which were administered to independent samples of 243, 299 and 961 gamers. The qgraph R package was used to perform network analyses of the RPVG items and gameplay style factors, employing the machine learning-based adaptive LASSO technique to estimate a partial correlation matrix from a set of variables as a Pairwise Markov Random Field. Gamers higher in Immersion tended to play for escapism, distraction, and fantasy, while social gamers played for excitement, energy, and self-expression. Network analysis and graph theory illustrate the central role of stress relief in the network of Reasons for Playing Video Games and shows that playing when feeling stressed is strongly linked with Immersion.

Cybersecurity is an issue of great concern today; data breaches are becoming more frequent and are causing huge economic losses in almost all the industry sectors. The majority of them are caused by malicious or criminal attacks perpetrated by individuals also known as “hackers”. Although the mainstream portrait of hackers nowadays brings to mind the idea of cybercriminals, not all hackers are malicious ones. The word hacker in its original sense only describes a computer enthusiast and a skilled programmer who was eager to learn how computers work. The key to distinguish a good or a bad hacker lies only in the specific intent and the permission to hack. Recently many companies are indeed hiring hackers to test their systems and protect them from the malicious attacks. The strength of good hackers is that they possess the same skills as malicious ones but they use them to enhance security. At the present stage, the process of hiring candidates for internet security positions for the majority of organizations, and business corporations relies mainly on interviews, while few of them advertise some sort of hacking challenges to be solved by potential applicants in order to evaluate upfront their skills and abilities. Moreover, an in-depth review of the literature has revealed that, so far, no systematic investigation has been carried out on the cognitive skills that characterise ethical hackers, experts who are professionally trained to protect systems’ security. The present PhD thesis offers a contribution that starts filling this gap in the literature with an exploratory investigation on the cognitive skills related with hacking expertise on a behavioural level. Findings show that hackers possess stronger systemizing traits as compared to the general population, and suggest a role of the ability to systemize on hacking performance. Moreover, performance on hacking-related tasks is shown to be related with mental rotation abilities and a field independent cognitive style. These findings have both theoretical and practical applications that are extensively discussed; together with possible future directions.

The aim of this research thesis was to investigate whether there are any cognitive factors that might influence reported dream colour. This question was prompted by the existence of a period of time in the early 20th century when the majority of people reported having greyscale dreams, and coloured dreaming was treated as an anomaly. On the level of individual differences, age, visual imagery abilities and memory for colour were singled out as the potential contributors to reports of greyscale television and the changes in the methodology of research were preliminarily identified as the possible causes of the historical trends in the colour of dreams, and the first empirical studies in this thesis address these issues. Subsequent studies explored the role of visual imagery ability, and individual differences in cognitive representation and memory in determining the reporting of colour in dreams. Overall a total of seven studies are reported The range of methods employed in these studies was diverse and required the development of new measures of colour memory and visual imagery. Some studies employed diaries to gather dream data and allowed cross-sectional (e.g. age) or cross-cultural comparisons. Others were more laboratory-based and explored data concerning visual memory and imagery performance with diverse dependent measures (e.g. response time data). In addition these studies involved the development of a novel coding scheme for visual dream content. While it was impossible to decisively support or disprove the idea that greyscale dream reports reflect genuine dream experiences, the research carried out for this thesis provided many fascinating insights into the factors that determine how we dream and how we report our dreams, highlighting the role of our cognitive abilities and preferences. Moreover, the studies have uncovered novel ways in which visual imagery preferences shape how we remember and report our experiences. The implications of these findings are important not just for the methodology of dream research, but for the whole field of cognitive and applied psychology

La mémoire prospective est une fonction cognitive complexe sollicitée quotidiennement en particulier chez les personnes âgées qui sont, par exemple, fréquemment amenées à se souvenir de prendre un traitement médicamenteux. Cette thèse conduite dans une perspective différentielle était guidé par deux objectifs. Le premier était d’identifier les mécanismes cognitifs sous-tendant le déclin lié à l’âge à des tâches de laboratoire et à des tâches naturelles de mémoire prospective. Le second était d’étudier les possibilités d’amélioration de la mémoire prospective chez la personne âgée. Quatre études ont donc été conduites auprès de personnes âgées. Les deux premières études ont permis d’avoir une meilleure compréhension des effets du vieillissement sur la mémoire prospective en mettant en évidence le rôle médiateur de la mémoire rétrospective et du contrôle exécutif dans le déclin lié à l’âge de la mémoire prospective. La troisième étude a notamment montré que les personnes âgées semblent spontanément compenser certaines difficultés de mémoire prospective en ayant recours à des aides mnésiques externes. Ces trois études nous ont permis d’élaborer et de tester l’effet d’un programme d’intervention, visant à améliorer la mémoire prospective, basé sur le renforcement de la mémoire rétrospective, du contrôle exécutif et de certaines connaissances méta-mnésiques. Les résultats n’ont pas mis en évidence d’effet de l’intervention. Ces résultats suggèrent que des interventions individualisées ciblées sur des difficultés spécifiques seraient peut-être plus adaptées que des interventions destinées à améliorer le fonctionnement global de la mémoire prospective de la personne âgée / Prospective memory is a complex cognitive function requested to remember a planned action. For example, this function is particularly important in elderly people to remember taking medication at the appropriate time. Two key objectives were pursued in an interindividual differences approach. The first goal was to have a better understanding of prospective memory in aging people. Thus, we wanted to identify the cognitive mechanisms underlying the age-related decline in laboratory and naturalistic prospective memory tasks. The second goal was to estimate how prospective memory can be improved in elderly people. To that end, we performed four studies using samples of aging people. The results of the two first studies indicated that retrospective memory and executive control processes mediate the relation between age and prospective memory. In the third study, the results showed that elderly people compensated spontaneously some of their prospective memory problems using external memory aids. These studies allowed us to develop and to test a cognitive intervention program based on the reinforcement of retrospective memory, executive control processes, and metacognitive knowledge. The results indicated any effect of the intervention program on prospective memory performance. These suggest that individualized cognitive interventions focused on specific prospective memory problems would be more suitable than interventions designed to improve the global functioning of prospective memory in elderly people

<p><p>Previous research has indicated that meaningful background speech affects individuals reading comprehension performance differently and that this difference is related to working memory capacity. But what mechanism in working memory that is involved is not well understood. The present study’s main purpose was to investigate if individual differences in susceptibility to effects of speech on reading comprehension are moderated by working memory capacity as measured by the number updating task and two different mechanisms within this construct; delayed suppression (i.e. the inhibition of information that once was task-relevant but no longer is) and immediate suppression (i.e. the inhibition of processed but irrelevant information, while withholding attention focused on the to-be-recalled task-relevant items). Forty participants performed a number updating task and a reading comprehension task in silence and with meaningful background speech. The results indicated that the immediate suppression mechanism moderates the effects of background speech on reading comprehension. Those who can’t handle the interference from the background speech let the task-irrelevant information interfere with the ongoing cognitive task and therefore are more likely to be distracted by the background speech while reading a text.</p></p>