Major depressive disorder (MDD) will soon represent the most costly and debilitating disorder in the world. Yet, a clear model of the mechanisms underlying MDD remains elusive. This lack of clarity obscures efforts to prevent and treat MDD more effectively. This dissertation seeks to advance an integrated model of the mechanisms underlying MDD across cognitive, neural, and genetic levels of analysis. Building on the empirical foundation of cognitive theories of MDD, the dissertation includes three studies that help address questions about the cognitive mechanisms underlying depression vulnerability and maintenance. Specifically, the three studies focus on identifying 1) how elaborative processing biases, including attentional biases and rumination, give rise to specific symptoms of MDD and 2) elucidating biological mechanisms that may give rise to these biases. Together, these studies help advance an integrated model of MDD that, ultimately, may help facilitate the prevention and treatment of this costly and debilitating disorder. / text

Football penalty kicks are having increasing influence in today’s professional game. Despite this, little scientific evidence currently exists to ascertain the mechanisms behind performance failure in this task and/or the efficacy of training designed to improve penalty shooting. In a football penalty kick it has been reported that the majority of kickers do not look to the area they wish to place the ball; preferring to focus on the ‘keeper and predict anticipatory movements before shooting. Such a strategy seems counterproductive and contradictory to current research findings regarding visually guided aiming. Coordination of eye and limb movements has been shown to be essential for the production of accurate motor responses. A disruption to this coordination not only seems to negatively affect performance, but subsequent motor responses seem to follow direction of gaze. Thus, where the eyes lead actions tend to follow. In study 1, ten participants were asked to kick a standard sized football to alternate corners of a goal, whilst looking centrally and whilst looking where they intended to hit. This disruption of eye-limb coordination brought about a 15% reduction in kicking accuracy. When participants were asked to fixate centrally, their shots hit more centrally (17cm) than when they were allowed to look where they intended to hit. These results were in spite of no significant differences between the number of missed shots, preparation time and ball speed data across conditions. We concluded that centrally focused fixations dragged resultant motor actions inwards towards more central target locations. Put simply, where the eyes looked shots tended to follow. The second study sought to test the predictions of attentional control theory (ACT) in a sporting environment in order to establish how anxiety affects performance in penalty kicks. Fourteen experienced footballers took penalty kicks under low- and high-threat counterbalanced conditions while wearing a gaze registration system. Fixations to target locations (goalkeeper and goal area) were determined using frame-by-frame analysis. When anxious, footballers made faster first fixations and fixated for significantly longer toward the goalkeeper. This disruption in gaze behaviour brought about significant reductions in shooting accuracy, with shots becoming significantly centralized and within the goalkeeper’s reach. These findings support the predictions of ACT, as anxious participants were more likely to focus on the “threatening” goalkeeper, owing to an increased influence of the stimulus-driven attentional control system. A further prediction of ACT is that when anxious, performers are more likely to be distracted, particularly if the distracter is threat related. When facing penalty kicks in football (soccer), goalkeepers frequently incorporate strategies that are designed to distract the kicker. However, no direct empirical evidence exists to ascertain what effect such visual distractions have on the attentional control, and performance, of footballers. In the third study, eighteen experienced footballers took five penalty kicks under counterbalanced conditions of threat (low vs. high) and goalkeeper movement (stationary vs. waving arms) while wearing eye-tracking equipment. Results suggested that participants were more distracted by a moving goalkeeper than a stationary one and struggled to disengage from a moving goalkeeper under situations of high threat. Significantly more penalties were saved on trials when the goalkeeper was moving and shots were also generally hit closer to the goalkeeper (centrally) on these trials. The results provide partial support for the predictions of attentional control theory and implications for kickers and goalkeepers are discussed. The previous studies showed that anxiety can disrupt visual attention, visuomotor control and subsequent shot location in penalty kicks. However, optimal visual attention has been trained in other far aiming skills, improving performance and resistance to pressure. In study 4, we therefore asked a team of ten university soccer players to follow a quiet eye (QE; Vickers, 1996) training program, designed to align gaze with aiming intention to optimal scoring zones, over a seven week period. Performance and gaze parameters were compared to a placebo group (ten players) who received no instruction, but practiced the same number of penalty kicks over the same time frame. Results from a retention test indicated that the QE trained group had more effective visual attentional control; were significantly more accurate; and had 50% fewer shots saved by the goalkeeper than the placebo group. Both groups then competed in a penalty shootout to explore the influence of anxiety on attentional control and shooting accuracy. Under the pressure of the shootout the QE trained group failed to maintain their accuracy advantage, despite maintaining more distal aiming fixations of longer duration. The results therefore provide only partial support for the effectiveness of brief QE training interventions for experienced performers. This series of studies are the first to explore the gaze behaviour of football penalty takers in a quest to uncover and understand anxiety’s negative influence on attentional control and performance. They are also the first to explore the efficacy of goalkeeper distractions and training in improving performance from both the goalkeeper’s and kicker’s perspective. The results of these studies conclude that when anxious, penalty takers show an attentional bias toward the ‘threatening’ goalkeeper that can be increased and utilised by a goalkeeper employing distraction techniques and that penalty takers do benefit, to some extent, from a gaze-based pre-shot routine

Eating disorders, such as anorexia and bulimia nervosa, have profound negative effects on the quality of life of both affected individuals and their families. Behavioral approaches such as cognitive-behavioral therapy (CBT) are commonly used for the treatment of these disorders. CBT teaches skills to restructure maladaptive thought patterns as a method of altering feelings and behaviors. However, even after CBT, 50-70% of women with bulimia and 67-87% of women with anorexia report continued eating disordered thoughts, feelings and behaviors. Measuring underlying cognitive processes such as orienting, maintaining, and executive attention in individuals with eating disorder symptomatology might be an important first step in improving these existing therapies. Attentional biases can be identified using a variety of techniques, including eye movement in response to stimuli (gaze patterns; focal points) as assessed by sophisticated eye tracking tasks. The current project sought to evaluate eye movement behavior related to body dissatisfaction, and to assess the feasibility of modifying attention. Participants (N = 1017) completed survey measures assessing disordered eating and body image (n = 1011), and participants meeting eligibility requirements participated in the in-person eye-tracking assessment (n = 85). Overall, longer gaze duration was associated with more dissatisfying body regions, and the attention modification intervention decreased time spent looking at the most dissatisfying region. Gaze time on the most dissatisfying body region was not different for self images compared with other images, nor was there an influence of level of shape concern. Body image anxiety also reduced after the attention modification intervention. These results suggest that it is feasible to modify attention biases related to body dissatisfaction. Implications and future extensions of this study are discussed.

Les recherches en psychopathologie cognitive ont montré que le biais attentionnel vers l'information menaçante contribue au développement et au maintien de l'anxiété. La difficulté rencontrée par les individus anxieux pour se désengager de l'information menaçante est l'une des principales composantes de ce biais attentionnel. Les recherches menées au cours de cette thèse ont permis, au moyen de paradigmes expérimentaux, de connaître : (1) les étapes du traitement de l'information concernées par la difficulté de désengagement attentionnel de mots menaçants et d'expressions faciales menaçantes, (2) l'importance de l'inhibition et du déplacement attentionnel dans la détérioration du désengagement attentionnel, (3) les relations entre la sous-échelle de focalisation attentionnelle de l'Attention Control Scale et le contrôle exécutif, et celle de déplacement attentionnel avec l'orientation de l'attention, et (4) la présence d'une difficulté de désengagement attentionnel des émotions négatives, non dans l'anxiété mais dans une situation stressante de menace du stéréotype de genre en mathématiques. Notre discussion reprend les résultats concernant le désengagement attentionnel et montre comment ils peuvent être étayés par des mesures telles que l'enregistrement des mouvements oculaires ou le recours à des investigations électrophysiologiques, auprès de populations cliniques et non-cliniques. Nous proposons aussi des pistes d'amélioration du dispositif d'entraînement attentionnel au désengagement, des mesures des fonctions d'inhibition et de déplacement attentionnel, ainsi que de nouvelles perspectives concernant l'évaluation du contrôle attentionnel par questionnaire et paradigmes expérimentaux. / Research in cognitive psychopathology showed that attentional bias towards threat contributes to development and maintenance of anxiety. Difficulty to disengage from threatening stimuli is one of the major components of attentional bias in anxiety. Research conducted in this thesis, using experimental paradigms, enabled to identify : (1) the stages of information processing involved in the impaired, disengagement from threatening words and threatening facial expressions, (2) the role of inhibition and attentional shifting in the impaired attentional disengagement, (3) the link between the attentional focusing subscale of Attentional Control Scale and executive control on the one hand, and betweeen the attentional shifting subscale and orientation of attention, on the other hand, and (4) attentional disengagement impairment from negative emotions in a stressful situation of mathematical gender stereotype threat. Finally, we discussed the results related to attentional disengagement and showed how they might be supported by eyes tracking or electrophysiological measures in clinical and non-clinical samples. We also put forward suggestions to improve attentional disengagement training and develop new measures of inhibition and attentional shifting functions. We also proposed new perspectives for the assessment of attentional control using questionnaire and experimental paradigms.

Entender como estímulos comerciais podem afetar o comportamento e a saúde de indivíduos é uma das principais questões da neurociência do consumidor. O principal objetivo desta tese foi investigar o papel da exposição à propaganda comercial no viés da atenção para pistas relacionadas a alimentos e álcool, através de um conjunto de estudos. Encontramos similaridades no uso de conteúdo visual em anúncios de tabaco, álcool e alimentos no Brasil (estudo 1); e elevada proporção (75%) de comerciais de alimentos não saudáveis na televisão brasileira (estudo 2). Observamos que comerciais podem afetar a atenção para alimentos, e assistir TV por si só pode influenciar a avaliação e a fome subjetiva em jovens adultos (estudo 3). Os resultados também revelaram associações entre exposição à publicidade de bebidas e ativações límbico-frontal em adolescentes (estudo 4). Estes estudos representam uma tentativa de identificar potenciais fatores de risco para o aumento do consumo de alimentos e abuso de álcool. / Understanding how commercial stimuli may affect individuals’ behavior and health is one of the main questions in Consumer Neuroscience. Thus, the main aim of this thesis was to investigate the role of exposure to commercial advertising on attentional bias for food and alcohol cues in a set of studies. There were similarities in the use of visuoperceptual content in advertisements for tobacco, alcohol and food in Brazil (study 1); and high proportion (75%) of unhealthy food commercials in the Brazilian television (study 2). We found that commercial advertisements can affect attention to food, and watching TV per se can influence affect and subjective hunger in young adults (study 3). Results also revealed associations between exposure to alcohol marketing and limbic-frontal activations in adolescents (study 4). Altogether, these results represent an attempt toward identifying possible risk factors for increased energy intake and alcohol misuse.

O viés atencional e a fissura para pistas associadas ao consumo do crack, além do perfil do consumidor e padrão de consumo de crack, foram temas explorados na presente tese. Para fins de abarcar a temática pretendida foram construídos três artigos. O primeiro artigo “Profile and Pattern of Crack Cocaine Consumption among Inpatients in a Brazilian Psychiatric Hospital” teve por objetivo principal a descrição do perfil e padrão de uso de crack de dependentes em tratamento tipo internação. O artigo “Avaliação do Viés Atencional em Usuários de Cocaína: Revisão Sistemática da Literatura” teve o intuito de revisar os estudos sobre viés atencional (VA) para pistas relacionadas à cocaína, descrevendo as principais tarafes e métodos utilizados. Por último, o terceiro artigo “Medidas de Reatividade a Pistas na Dependência de Crack: Viés Atencional e Fisssura” descreveu o processo de construção de uma tarefa de avaliação do VA ou Visual Probe Task para pistas associadas ao consumo do crack e, também, avaliou o VA e fissura em relação a essa substância. Dependentes químicos tendem a alocar a atenção para estímulos/pistas relacionados às substâncias de abuso, fenômeno descrito como VA. A revisão da literatura sobre VA para pistas associadas à cocaína mostrou que essa relação ainda não foi bem descrita através da Visual Probe Task, tendo em vista que a maioria dos estudos utilizou a tarefa de Stroop para avaliação do VA. Em relação especifica ao crack, forma fumada de cocaína não foram encontrados estudos prévios com emprego de Visual Probe Task avaliando o VA. Portanto, nessa tese uma tarefa de atenção visual foi desenvolvida para avaliação do VA em dependentes de crack em tratamento do tipo internação. Da mesma forma, o perfil de 53 dependentes de crack em tratamento (tipo internação) foi explorado, eles eram jovens adultos (M=27,5 anos; DP=7,3), poliusuários de drogas, com várias tentativas anteriores de cessação do consumo. Então, no terceiro artigo, um experimento para avaliar VA e fissura em relação ao crack em 53 dependentes de crack (em tratamento internação), 24 dependentes de álcool (em tratamento internação) e em outro grupo composto de 17 indivíduos que nunca consumiram substâncias psicoativas, há exceção do álcool (mas sem preencher critério de uso abusivo) foi descrito. Na tarefa de atenção visual desenvolvida, os participantes tiveram que pressionar uma tecla em um teclado de computador para identificar um alvo que poderia estar localizado tanto ao lado esquerdo quanto direito do campo visual. A localização do alvo foi encoberta por um de 12 pares de imagens relacionadas ao crack e seus controles pareados por stimulus onset asynchronies (SOA) 50, 500, 2000ms. O auto-relato de fissura foi obtido antes e depois da tarefa de atenção visual. Apenas os dependentes de crack exibiram VA para pistas relacionadas ao crack no SOA 2000ms (M=28,7; DP=101), mas não em outros SOAS, indicando padrão de manutenção da atenção para os estímulos. Somente dependentes de crack apresentaram aumento de fissura após a tarefa, enquanto os outros grupos não. Apesar das dificuldades intrínsecas relacionadas ao trabalho com dependentes de crack em tratamento e poliusuários de drogas, o presente estudo parece ser o primeiro a avaliar o VA em dependentes de crack com emprego de Visual Probe Task (tarefa de atenção visual). / The attentional bias (AB) to cocaine crack cues and craving related to cocaine crack were explored in this thesis. Furthermore, the consumer profile and the pattern of crack consumption were evaluated. For purposes of embracing the intended thematic three articles were constructed. The first article “Profile and Pattern of Crack Cocaine Consumption among Inpatients in a Brazilian Psychiatric Hospital” aimed to describe the profile and pattern of crack use among dependents inpatients. The article “Assesment ofAttentional Bias in Cocaine Users: Systematic Review of the Literature” was developed to review studies on AB to cocaine related cues, describing the main tasks and methods. Lastly, the third article “Measures of Cue Reactivity in Cocaine Crack Dependence: Attentional Bias and Craving” described the process of constructing a Visual Probe Task to evaluate Ab to crack cues and also assessed the AB and craving in relation to crack. Addicts tend to allocate attention to substance-related stimuli, a phenomenon described as AB. A review of recent literature about AB to cocaine showed that this relationship has not yet been described through a Visual Probe Task, given that most studies used the Stroop task. In relation to crack cocaine no studies were found yet using Visual Probe Task. Therefore, in this thesis, a Visual Probe Task was designed to evaluate AB in addicts to cocaine crack. Similarly, the profile of 53 cocaine crack inpatients was described, they were young adults (M=27.5 years; SD=7.3), polydrug users, with several previous cessation attempts. Then, in the third article a experiment to evaluate AB and craving in 53 cocaine crack addicted inpatiens, 24 alcohol-addicted inpatients and another group of 17 individuals who did not consume any psychoactive substances, except alcohol (but excluding alcohol abuse) was described. On performing the Visual Probe Task developed in our laboratory, participants had to press a key in a computer keybord to identify a probe located either on the left or right visual field. Probe location was covered by one of 12 pairs of crack-cocaine and matched control pictures for stimulus onset asynchronies (SOA) 50, 500 and 2000ms. Self-reported craving was assessed before and after task performance. Only crack dependents group exhibited AB related to crack cues in SOA 2000ms (M=28.7; SD=101) but not others SOAs, indicating a pattern of maintenance of attention towards the stimulus. Just crack dependents group presented increased craving after task performance, whereas other groups did not report craving for crack cocaine. Despite intrinsic difficulties related to work with polidrug inpatients, the present study is likely to be the first to assess AB in crack addicts using a Visual Probe Task.

Research suggests that the human attentional system is biased towards emotional events in the environment. This attentional bias is believed to be an adaptive function that can provide survival benefits for the organisms that possess it. Dispositional optimism is a trait defined as a general expectation that good things will happen in the future. This trait has received interest as an adaptive trait that has a multitude of psychological and physical benefits for the individuals who exhibit it. The aim of this study is to examine whether there is a difference in the attentional bias towards happy and angry facial expressions based on level of dispositional optimism using the dot-probe paradigm. Thirty-two psychologically and neurologically healthy females (mean age = 26.5, SD = 5.8) participated in the study. They completed a questionnaire measuring dispositional optimism and performed the dot-probe task in a laboratory setting in the University of Skövde. In the dot- probe task a short exposure (100 ms) of photographs depicting happy, angry and neutral facial expressions was used as emotional cues. A general bias towards happy faces across all participants was detected. Also, a clear trend towards an interaction between DO and AB to emotional faces was found in the group high in DO displaying and AB towards happy facial expressions. This study implies that for the psychologically and neurologically healthy population, a fast operating and automatic AB for positive stimuli exists, moreover, this AB may be modulated by individual differences in DO.

O consumo excessivo de álcool é recorrente entre universitários e está associado a inúmeras conseqüências negativas. Fatores ambientais (bottom-up) podem favorecer este consumo (ex.: influência do grupo, pistas associadas à droga). Além destes, fatores individuais podem influenciar o comportamento de beber desta população, entre eles fatores cognitivos (top-down). Bebedores freqüentes tendem a apresentar um viés atencional para estímulos associados ao álcool. Com o uso repetido do álcool, pistas ambientais associadas aos efeitos desta droga tornam-se salientes, em função de suas propriedades reforçadoras, atraindo a atenção do usuário em detrimento de outros estímulos e exacerbam o desejo de beber. O uso freqüente de álcool também tem sido relacionado a um conjunto de expectativas predominantemente positivas acerca dos seus efeitos e riscos para desenvolver dependência que podem influenciar o início e a manutenção do uso. Neste contexto, o objetivo deste estudo foi: a) examinar a relação entre o padrão de consumo e expectativas em relação aos efeitos do álcool entre universitários e b) desenvolver uma tarefa para investigar o viés atencional para pistas relacionadas ao álcool em indivíduos com diferentes padrões de consumo. Participaram deste estudo graduandos da UFRGS (N=79), do sexo masculino, com 22 anos de idade em média (dp=2,81). O padrão de consumo de risco e as expectativas positivas foram acessados através do Alcohol Use Disorders Identification Test (AUDIT) e do Inventário de Expectativas e Crenças Pesssoais acerca do Álcool (IECPA), respectivamente. Participaram deste estudo graduandos da UFRGS (N=79), do sexo masculino, com 22 anos de idade em média (dp=2,81). O padrão de consumo de risco e as expectativas positivas foram acessados através do Alcohol Use Disorders Identification Test (AUDIT) e do Inventário de Expectativas e Crenças Pesssoais acerca do Álcool (IECPA), respectivamente. Examinou-se o viés atencional através de uma tarefa computadorizada. O consumo de risco de álcool, que inclui o beber problemático e o padrão binge, estava associado a altas expectativas positivas em relação aos seus efeitos. Constatou-se que 43% dos participantes eram bebedores de alto risco para desenvolver dependência, conforme o AUDIT. Além disso, 68,4% deles foram caracterizados como bebedores com padrão binge de uso de álcool e 44,3% possuíam expectativas positivas em relação aos efeitos do álcool altas. Houve correlação entre beber problemático e expectativas positivas. Quanto à avaliação do viés atencional, não foi observado nenhum efeito de grupo, de tempo de exposição, nem de interação entre grupo e tempo de exposição. Identificar os fatores top down e bottom-up envolvidos no consumo de álcool de risco é essencial para formulação de modelos teóricos que compreendam este preocupante fenômeno. A avaliação das expectativas a respeito dos efeitos do álcool contribui para o planejamento de intervenções terapêuticas e estratégias preventivas mais precisas, visando a reduzir os riscos comportamentais e de saúde associados ao álcool. Além disso, o estudo do viés atencional pode favorecer o entendimento da relação entre fissura e atenção, da transição do uso ocasional para a dependência e da recaída. / The excessive alcohol consumption is recurrent among college students and it is associated with a variety of negative consequences. Environmental factors (bottom-up) can contribute to this phenomenon (group influences, drug cues). Furthermore, individual factors can also influence drinking behavior of this population, such as cognitive factors (top-down). Drug cues become highly salient as a result of their reinforcing properties, attracting the attention of the drug user in detriment of other stimuli. The exposure to drug cues can increase the desire to drink. Thus, heavy social drinkers show an attentional bias towards alcohol cues. The frequent alcohol use has also been related to a set of positive outcome expectancies and risk to develop drug dependence. These expectancies can influence the maintenance of drug intake. The aim of this study was: to examine the association of risk pattern and alcohol expectancies among college students and b) to develop a task to investigate attentional bias for alcohol cues in individuals with different drink patterns. Participants (N=79, mean age 22, dp=2,81) were college students. The risk pattern and the positive alcohol expectancies were assessed through Alcohol Use Disorders Identification Test (AUDIT) and Inventário de Expectativas e Crenças Pessoais acerca do Álcool (IECPA). The attentional bias was examined using a computerized task. The risk pattern, which includes drinking problematic and binge drinking, was associated with high positive expectancies. Results indicated that 43% of the participants had high risk to develop alcohol dependence. Moreover, 68.4% were binge drinkers and 44.3% had high positive alcohol expectancies. Risk pattern was associated with higher levels of positive alcohol expectancies. Related to the atencional bias assessment, there was not observed any group effect, exposition time, interaction between group and exposition time. Identifying bottom-up and top-down factors associated with the risk pattern of alcohol consumption is important to understand this preoccupant phenomenon. The alcohol expectancies assessment contributes to more efficient planning for therapeutical interventions and preventing strategies to reduce behavioral and health risks associated to the alcohol consumption. Moreover, the study of atencional bias can contribute to the understanding of the relationship between craving and attention, of the transition of the occasional use for the dependence and relapse.

Entender como estímulos comerciais podem afetar o comportamento e a saúde de indivíduos é uma das principais questões da neurociência do consumidor. O principal objetivo desta tese foi investigar o papel da exposição à propaganda comercial no viés da atenção para pistas relacionadas a alimentos e álcool, através de um conjunto de estudos. Encontramos similaridades no uso de conteúdo visual em anúncios de tabaco, álcool e alimentos no Brasil (estudo 1); e elevada proporção (75%) de comerciais de alimentos não saudáveis na televisão brasileira (estudo 2). Observamos que comerciais podem afetar a atenção para alimentos, e assistir TV por si só pode influenciar a avaliação e a fome subjetiva em jovens adultos (estudo 3). Os resultados também revelaram associações entre exposição à publicidade de bebidas e ativações límbico-frontal em adolescentes (estudo 4). Estes estudos representam uma tentativa de identificar potenciais fatores de risco para o aumento do consumo de alimentos e abuso de álcool. / Understanding how commercial stimuli may affect individuals’ behavior and health is one of the main questions in Consumer Neuroscience. Thus, the main aim of this thesis was to investigate the role of exposure to commercial advertising on attentional bias for food and alcohol cues in a set of studies. There were similarities in the use of visuoperceptual content in advertisements for tobacco, alcohol and food in Brazil (study 1); and high proportion (75%) of unhealthy food commercials in the Brazilian television (study 2). We found that commercial advertisements can affect attention to food, and watching TV per se can influence affect and subjective hunger in young adults (study 3). Results also revealed associations between exposure to alcohol marketing and limbic-frontal activations in adolescents (study 4). Altogether, these results represent an attempt toward identifying possible risk factors for increased energy intake and alcohol misuse.

O viés atencional e a fissura para pistas associadas ao consumo do crack, além do perfil do consumidor e padrão de consumo de crack, foram temas explorados na presente tese. Para fins de abarcar a temática pretendida foram construídos três artigos. O primeiro artigo “Profile and Pattern of Crack Cocaine Consumption among Inpatients in a Brazilian Psychiatric Hospital” teve por objetivo principal a descrição do perfil e padrão de uso de crack de dependentes em tratamento tipo internação. O artigo “Avaliação do Viés Atencional em Usuários de Cocaína: Revisão Sistemática da Literatura” teve o intuito de revisar os estudos sobre viés atencional (VA) para pistas relacionadas à cocaína, descrevendo as principais tarafes e métodos utilizados. Por último, o terceiro artigo “Medidas de Reatividade a Pistas na Dependência de Crack: Viés Atencional e Fisssura” descreveu o processo de construção de uma tarefa de avaliação do VA ou Visual Probe Task para pistas associadas ao consumo do crack e, também, avaliou o VA e fissura em relação a essa substância. Dependentes químicos tendem a alocar a atenção para estímulos/pistas relacionados às substâncias de abuso, fenômeno descrito como VA. A revisão da literatura sobre VA para pistas associadas à cocaína mostrou que essa relação ainda não foi bem descrita através da Visual Probe Task, tendo em vista que a maioria dos estudos utilizou a tarefa de Stroop para avaliação do VA. Em relação especifica ao crack, forma fumada de cocaína não foram encontrados estudos prévios com emprego de Visual Probe Task avaliando o VA. Portanto, nessa tese uma tarefa de atenção visual foi desenvolvida para avaliação do VA em dependentes de crack em tratamento do tipo internação. Da mesma forma, o perfil de 53 dependentes de crack em tratamento (tipo internação) foi explorado, eles eram jovens adultos (M=27,5 anos; DP=7,3), poliusuários de drogas, com várias tentativas anteriores de cessação do consumo. Então, no terceiro artigo, um experimento para avaliar VA e fissura em relação ao crack em 53 dependentes de crack (em tratamento internação), 24 dependentes de álcool (em tratamento internação) e em outro grupo composto de 17 indivíduos que nunca consumiram substâncias psicoativas, há exceção do álcool (mas sem preencher critério de uso abusivo) foi descrito. Na tarefa de atenção visual desenvolvida, os participantes tiveram que pressionar uma tecla em um teclado de computador para identificar um alvo que poderia estar localizado tanto ao lado esquerdo quanto direito do campo visual. A localização do alvo foi encoberta por um de 12 pares de imagens relacionadas ao crack e seus controles pareados por stimulus onset asynchronies (SOA) 50, 500, 2000ms. O auto-relato de fissura foi obtido antes e depois da tarefa de atenção visual. Apenas os dependentes de crack exibiram VA para pistas relacionadas ao crack no SOA 2000ms (M=28,7; DP=101), mas não em outros SOAS, indicando padrão de manutenção da atenção para os estímulos. Somente dependentes de crack apresentaram aumento de fissura após a tarefa, enquanto os outros grupos não. Apesar das dificuldades intrínsecas relacionadas ao trabalho com dependentes de crack em tratamento e poliusuários de drogas, o presente estudo parece ser o primeiro a avaliar o VA em dependentes de crack com emprego de Visual Probe Task (tarefa de atenção visual). / The attentional bias (AB) to cocaine crack cues and craving related to cocaine crack were explored in this thesis. Furthermore, the consumer profile and the pattern of crack consumption were evaluated. For purposes of embracing the intended thematic three articles were constructed. The first article “Profile and Pattern of Crack Cocaine Consumption among Inpatients in a Brazilian Psychiatric Hospital” aimed to describe the profile and pattern of crack use among dependents inpatients. The article “Assesment ofAttentional Bias in Cocaine Users: Systematic Review of the Literature” was developed to review studies on AB to cocaine related cues, describing the main tasks and methods. Lastly, the third article “Measures of Cue Reactivity in Cocaine Crack Dependence: Attentional Bias and Craving” described the process of constructing a Visual Probe Task to evaluate Ab to crack cues and also assessed the AB and craving in relation to crack. Addicts tend to allocate attention to substance-related stimuli, a phenomenon described as AB. A review of recent literature about AB to cocaine showed that this relationship has not yet been described through a Visual Probe Task, given that most studies used the Stroop task. In relation to crack cocaine no studies were found yet using Visual Probe Task. Therefore, in this thesis, a Visual Probe Task was designed to evaluate AB in addicts to cocaine crack. Similarly, the profile of 53 cocaine crack inpatients was described, they were young adults (M=27.5 years; SD=7.3), polydrug users, with several previous cessation attempts. Then, in the third article a experiment to evaluate AB and craving in 53 cocaine crack addicted inpatiens, 24 alcohol-addicted inpatients and another group of 17 individuals who did not consume any psychoactive substances, except alcohol (but excluding alcohol abuse) was described. On performing the Visual Probe Task developed in our laboratory, participants had to press a key in a computer keybord to identify a probe located either on the left or right visual field. Probe location was covered by one of 12 pairs of crack-cocaine and matched control pictures for stimulus onset asynchronies (SOA) 50, 500 and 2000ms. Self-reported craving was assessed before and after task performance. Only crack dependents group exhibited AB related to crack cues in SOA 2000ms (M=28.7; SD=101) but not others SOAs, indicating a pattern of maintenance of attention towards the stimulus. Just crack dependents group presented increased craving after task performance, whereas other groups did not report craving for crack cocaine. Despite intrinsic difficulties related to work with polidrug inpatients, the present study is likely to be the first to assess AB in crack addicts using a Visual Probe Task.