The attribution of incentive salience to cues that become associated with drugs of abuse is a critical characteristic of individuals who may be vulnerable to drug addiction. Rodents with the propensity to sign track are thought to be vulnerable to drug abuse. The goal of the current work was to investigate whether sign trackers (STs) would acquire cocaine conditioned place preference (CPP) to a discrete cue using an avian species. In Experiment 1, sign and goal trackers (GTs) were first identified using a one third rank order split. Following identification, cocaine-CPP was conducted with a discrete cue in each end chamber. Contrary to previous research, results showed that GTs showed a CPP to the discrete cue but STs did not. Experiment 2 was conducted to determine whether sign and GTs had been misclassified with the rank order split. Experiment 2 compared the rank order method with a t-test method (absolute criterion). Misclassification of both sign and GTs occurred using the rank order split. The findings indicated that use of a more accurate method to identify sign and GTs may have led to different results for Experiment 1. The t-test method may be useful for models that require identification of STs.

En Europe centrale et, en particulier en Moravie et en Silésie, se forment entre 28.000 - 25.500 BP non calibré des concentrations des sites situés le long d'un corridor naturel, le seul passage reliant l'Europe du Nord et du Sud. Le terme de «Pavlovien» fut créé pour englober ces sites qui avec leur richesse matérielle, sociale, culturelle et symbolique représentent un témoignage extraordinaire de ce que furent les sociétés du Paléolithique supérieur. Afin de revisiter la définition du Pavlovien, nous proposons une nouvelle lecture de leurs industries lithiques. Un examen approfondi réalisé sur des sites classiques mais également sur des sites nouvellement fouillés nous a conduit à proposer une tripartition des ensembles selon leurs caractéristiques éco-typo-technologique (Groupe à microscies, Groupe à microlithes géométriques et Groupe à pointes de Milovice ). Les populations d'au moins de deux de ces groupes semblent être porteuses d'une tradition lithique particulière et d'une culture matérielle riche et révélatrice de comportements sociaux structurés et récurrents qui semble plaider en faveur d'un fort degré d'homogénéité culturelle. / In central Europe, and in particular in Moravia and in Silesia, some concentrations of archaeological sites, dated from 28.000 to 25.500 BP, appeared all way long a natural corridor, which is the only passageway between Northern and Southern Europe. These sites have provided a wide range of artifacts, bringing many data about social, cultural and symbolic aspects of the Upper Paleolithic societies. They are now known as the «Pavlovian complex». In order to refine the definition of the « Pavlovian », this thesis seeks to renew the reading of lithic industries. This study includes both the classical sites and the ones recently excavated. It leads t subdivide the Pavlovian into three mains groups according to their eco-typo-technologica characteristics (the group with microsaws, the group with geometric microliths and the group wit the point of Milovice ). At least two of these groups present specific lithic tradition and an abundan material culture that reveals some social behaviors, both well structured and recurring, which plead in favour of a high level of cultural homogeneity.

No description available.

Le conditionnement Pavlovien, l'acquisition de réponses vers des stimuli neutres associés à des récompenses, et le conditionnement instrumental, l'expression de comportements pour atteindre des buts, sont au cœur de nos capacités d'apprentissage. Ils sont souvent étudiés séparément malgré les preuves de leur enchevêtrement. Les modèles de conditionnement instrumental reposent sur le formalisme de l'apprentissage par renforcement (RL), alors que les modèles du conditionnement Pavlovien reposent surtout sur des architectures dédiées souvent incompatibles avec ce formalisme, compliquant l'étude de leurs interactions.Notre objectif est de trouver des concepts, qui combinés à des modèles RL puissent offrir une architecture unifiée permettant une telle étude. Nous développons un modèle qui combine un système RL classique, qui apprend une valeur par état, avec un système RL révisé, évaluant les stimuli séparément et biaisant le comportement vers ceux associés aux récompenses. Le modèle explique certaines réponses inadaptées par l'interaction néfaste des systèmes, ainsi que certaines différences inter-individuelles par une simple variation au niveau de la population de la contribution de chaque système dans le comportement global.Il explique une activité inattendue de la dopamine, vis-à-vis de l'hypothèse qu'elle encode un signal d'erreur, par son calcul sur les stimuli et non les états. Il est aussi compatible avec une hypothèse alternative que la dopamine contribue aussi à rendre certains stimuli recherchés pour eux-mêmes. Le modèle présente des propriétés prometteuses pour l'étude du conditionnement Pavlovien,du conditionnement instrumental et de leurs interactions. / Pavlovian conditioning, the acquisition of responses to neutral stimuli previously paired with rewards, and instrumental conditioning, the acquisition of goal-oriented responses, are central to our learning capacities. However, despite some evidences of entanglement, they are mainly studied separately. Reinforcement learning (RL), learning by trials and errors to reach goals, is central to models of instrumental conditioning, while models of Pavlovian conditioning rely on more dedicated and often incompatible architectures. This complicates the study of their interactions. We aim at finding concepts which combined with RL models may provide a unifying architecture to allow such a study. We develop a model that combines a classical RL system, learning values over states, with a revised RL system, learning values over individual stimuli and biasing the behaviour towards reward-related ones. It explains maladaptive behaviours in pigeons by the detrimental interaction of systems, and inter-individual differences in rats by a simple variation at the population level in the contribution of each system to the overall behaviour. It explains unexpected dopaminergic patterns with regard to the dominant hypothesis that dopamine parallels a reward prediction error signal by computing such signal over features rather than states, and makes it compatible with an alternative hypothesis that dopamine also contributes to the acquisition of incentive salience, making reward-related stimuli wanted for themselves. The present model shows promising properties for the investigation of Pavlovian conditioning, instrumental conditioning and their interactions.

Alcohol use disorder (AUD) is a mental disorder that negatively affects personal health and burdens the global health system. Alcohol-attributed harms can also extend beyond the drinkers to other people in the society through increased road traffic accidents and more interpersonal violent behaviors. The effects of this disorder make it crucial to investigate predisposing mechanisms in order to identify at-risk individuals and further develop novel interventions. Although aberrant learning and dysfunctions in decision-making have been observed in individuals with AUD, it is not yet clear whether they predispose the development of risky drinking behaviors or result from repetitive alcohol use. To disentangle this, we studied the drinking behaviors of a community sample comprising participants who were 18–24, which is when the prevalence of alcohol use typically peaks. This thesis investigates whether two types of learning mechanisms—the balance between goal-directed and habitual control and the susceptibility to interference between Pavlovian cues and instrumental behaviors—are associated with the development of risky alcohol drinking behaviors. For Study 1, we assessed how goal-directed and habitual controls at 18 predispose alcohol use development over the course of 3 years. Goal-directed and habitual control, which are informed by model-based (MB) and model-free (MF) learning, were assessed with a two-step sequential decision-making task during functional magnetic resonance imaging. Three-year drinking trajectories were constructed based on the Alcohol Use Disorders Identification Test (AUDIT-C; assessed every 6 months) and a gram/drinking occasion measure (binge drinking score; assessed yearly). Latent growth curve models were applied to examine how the MB and MF controls were associated with the drinking trajectories. We found that MB control was negatively associated with the development of the binge drinking score trajectory. In contrast, MF reward prediction signals in the ventromedial prefrontal cortex and the ventral striatum (VS) were associated with a higher starting point and a steeper increase/less decrease in AUDIT-C, respectively. For Study 2, we investigated the cross-sectional association between the susceptibility to interference between Pavlovian cues and instrumental behaviors and risky (binge) drinking behaviors at age 18. During a Pavlovian-to-instrumental transfer (PIT) task, the participants were instructed to “collect good shells” and “leave bad shells” while the appetitive (monetary gain) or aversive (monetary loss) Pavlovian cues were presented in the background. The behavioral interference PIT effect was characterized by an increased error rate (ER) during incongruent trials (“collecting good shells” in the presence of an aversive Pavlovian cue or “leaving bad shells” during the presentation of an appetitive Pavlovian cue) in comparison to congruent ones. Overall, the individuals demonstrated a substantial behavioral PIT effect. Neural PIT correlates were found in the VS, dorsomedial, and lateral prefrontal cortices (dmPFC and lPFC, respectively). High-risk drinkers, in comparison to low-risk drinkers, exhibited a stronger behavioral PIT effect, decreased lPFC responses, and increased trend-level VS responses. Moreover, the effective connectivity from the VS to the lPFC during the incongruent trials was weaker for the high-risk drinkers, which indicates that the altered interplay between bottom-up and top-down neural responses may contribute to the poor interference control performance of this group. During Study 3, we further examined whether the susceptibility to Pavlovian cues during conflict trials was associated with the development of drinking behaviors over 6 years from ages 18 to 24. The drinking behaviors were again constructed based on the AUDIT-C and the binge drinking score. The PIT task was assessed at ages 18 and 21. Following Study 2, the increased ER in the incongruent condition compared with the congruent condition (along with the neural responses in the VS, lPFC, and dmPFC during the incongruent trials) were included in the latent growth curve models as predictors. A stronger VS response during a conflict at age 18 was associated with a higher starting point in both drinking trajectories but was negatively associated with the development of the binge drinking score trajectory. At age 21, high ER and enhanced neural responses in the dmPFC were associated with a risky AUDIT-C trajectory that started to emerge and develop until age 24. Through exploratory cluster analyses of the drinking trajectories, we identified two subgroups: the drinking behavior in the 'late riser' group escalated after age 21, whereas the drinking of 'early peakers' culminated at this age and then declined. The late risers displayed enhanced dmPFC responses and higher ER during conflict at age 21. Interestingly, this group also exhibited an increased ER from ages 18 to 21. Taken altogether, the unbalanced goal-directed to habitual control, informed by less MB and more MF control, appears to be a strong predisposing candidate mechanism that underlies the development of risky drinking behaviors during young adulthood. At age 18, the susceptibility to interference between Pavlovian cues and instrumental behaviors was associated with risky drinking behavior. The development of risky drinking behaviors over the 6 years was associated with the behavioral interference PIT effect at age 21 and its change from ages 18 to 21. Researchers could further explore the dynamics in PIT to predict risky drinking behaviors in the future.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Chez l’espèce humaine comme pour de nombreuses autres espèces animales, lorsque des stimuli environnementaux précèdent de façon régulière la présentation d’événements importants pour un individu, ces stimuli vont acquérir sous certaines conditions la capacité à évoquer des comportements dits d’anticipation. Cette capacité est considérée par de nombreux auteurs comme ayant une haute valeur adaptative, favorisant le contact avec des événements appétitifs et permettant l’évitement d’événements aversifs. Ces dernières décennies, deschercheurs ont initié un rapprochement entre le phénomène d’anticipation et le conditionnement Pavlovien. Ce rapprochement repose à la fois sur une similarité dans les caractéristiques des événements mis en jeux mais surtout sur de nombreux effets et phénomènes semblables, amenant ces auteurs à considérer que les comportements ditsd’anticipation, d’une façon générale, reposeraient sur le processus Pavlovien. Leconditionnement Pavlovien offre une littérature extrêmement riche dont l’une des principalesquestions de recherche concerne le problème des conditions à l’apparition du processus.Parmi les hypothèses existantes, l’Hypothèse de l’Information est sans aucun doute l’une desplus importantes par son influence. Selon cette hypothèse, un apprentissage associatifPavlovien n’aura lieu que lorsqu’un événement important sera présenté de façon inattendu à un sujet, et l’apprentissage, ou les associations apprises, ne porteront que sur des stimuli prédictifs de l’événement important (i.e. permettant son anticipation). A travers deux expériences appliquant une procédure de conditionnement rétrograde à une procédure de renforcement conditionné, nous avons cherché à tester les propositions faites par cette hypothèse. Nos résultats vont directement à l’encontre de ces propositions et vont au contraire dans le sens de deux autres propositions théoriques faites sur le conditionnement Pavlovien,illustrées par le modèle SOP et l’Hypothèse du Codage Temporel. Ces deux propositions sont testées au sein d’une troisième et dernière expérience, dont les implications pour ces modèles comme pour la conceptualisation du conditionnement Pavlovien et de l’anticipation de façon générale sont discutées. / In human and non-human animals, environmental stimuli that reliably accompany the presentation of significant events are able after repeated exposures of eliciting anticipatory behaviors. Many authors underlined the adaptive value of anticipatory responses, and suggested a connection with Pavlovian conditioning. Linking anticipatory behaviors to Pavlovian conditioning is supported by the similarity in procedure (i.e. a pairing between a neutral stimulus with a significant event), but also on the common effects and phenomena, and the authors assume that Pavlovian conditioning is the process underlying the anticipation of events. This assumption is at the heart of the Information Hypothesis, and more generally of a functional and predictive perspective of Pavlovian conditioning. According to the Information Hypothesis, Pavlovian conditioning only occurs when an unexpected significant event is presented, and learning (i.e. the formation of association) would be about stimuli that allow the anticipation of the significant event. Using a backward conditioning procedure in a conditioned reinforcement preparation, we tested the assumptions made by the Information Hypothesis. The results found argue against the Information Hypothesis and, in contrast, support the assumption made by two others types of leaning models, illustrated by the Temporal Coding Hypothesis and the SOP model. The Temporal Coding Hypothesis and SOP are tested in a third experiment. Implications for Pavlovian conditioning models and anticipatory behaviors in general are discussed.

Estudos reportando que a autoadministração repetida de drogas de abuso causa mudanças comportamentais, e na expressão de FosB, diferentes às causadas pela administração passiva repetida da mesma droga, em conjunto com estudos de discriminação de estímulos, têm sido chaves para compreender a dependência às drogas. Neste estudo se apresentam resultados de 3 experimentos que avaliaram diferenças gênicas e comportamentais entre a autoadministração de morfina e cocaína sob uma contingência operante, e a administração passiva destas drogas sob uma contingência Pavloviana, usando um modelo de administração de drogas acoplado e um protocolo de transferência operante-Pavloviana (PIT) seletiva em ratos. Os sujeitos foram distribuídos em três grupos: Administração por Contingência Operante (CO), Administração por Contingência Pavloviana (CP) e Controle (Ctr). No Experimento 1, cada sujeito do grupo CO foi exposto a sessões de autoadministração endovenosa de morfina. Depois, a expressão do gene FosB foi medida utilizando uma técnica imuno-histoquímicas em diferentes áreas do cérebro. No Experimento 2 os ratos foram expostos a um protocolo de PIT, treinando de forma inicial as contingências operante e Pavloviana separadamente, em associação a S1, utilizando infusões de morfina como reforçador. Em seguida foi treinado um encadeado de respostas (busca e administração) e finalmente, os sujeitos foram testados para avaliar o controle de estímulos que S1 adquiriu sobre as respostas de busca e administração. O Experimento 3 foi realizado utilizando os métodos dos primeiros dois experimentos, utilizando cocaína como reforçador. Em conjunto, os dados imunohistoquímicos e comportamentais sugerem que a maior expressão de FosB em subáreas envolvidas na dependência às drogas, em comparação entre os grupos CO e CP, está relacionada ao controle de estímulos estabelecido por S1 pelas diferentes contingências de aprendizagem. Ainda, os resultados apontam que estas áreas em que se encontrou uma expressão de FosB diferencial por diferentes contingências de administração de drogas coincidem com algumas das reportadas como envolvidas na PIT. Os resultados estão em concordância com estudos que reportam que a administração repetida de uma droga em contingências operantes ou pavlovianas alteram diferencialmente estruturas cerebrais envolvidas nos processos da dependência às drogas e apoiam a literatura que reporta que o estabelecimento de controle de estímulos que caracteriza a dependência se pode estabelecer por processos de aprendizagem na contingência operante e Pavloviana / Studies reporting that repeated drug self-administration produces behavioral changes, and in FosB expression, different from those produced by repeated passive administration of the same drug have been very important, together with stimulus control studies, have been the key to understand mechanisms underlying drug abuse. This study presents results from 3 experiments evaluating gene and behavioral differences between self-administration of morphine and cocaine under an operant contingency, and passive administration of these drugs under a Pavlovian contingency, using a yoked drug administration model and a selective Pavlovian to instrumental transfer (PIT) protocol in rats. Subjects were divided into three groups: Operant Contingency Administration (CO), Pavlovian Contingency Administration (CP) and Control (Ctr). In Experiment 1, each subject in the CO group was exposed to intravenous morphine self-administration sessions. Then, expression of FosB gene was measured using an immunohistochemical technique in different areas of the brain. In Experiment 2 rats were exposed to a PIT protocol, initially training the operant and Pavlovian contingencies separately in association with S1, using morphine infusions as a reinforcer. Then a chain of responses (seeking and taking) was trained and finally, subjects were tested to evaluate S1 stimulus control over search and administration responses. Experiment 3 was performed using the methods from the first two experiments, using cocaine as a reinforcer. Together, immunohistochemical and behavioral data interact and suggest that a higher expression on FosB expression in subareas involved in drug dependence, in comparison between CO and CP groups, is related to stimuli control established by S1 through the different learning contingencies. Moreover, results point out these same areas in which different FosB expression was found by different drug administration contingencies match some of those reported as being involved in PIT. Results are in agreement with studies reporting that repeated administration of a drug in operant or pavlovian contingencies differentially alter brain structures involved in drug dependence processes and support literature reporting the establishment of stimulus control characterizing addiction can be establish by learning processes in the operant and Pavlovian contingencies

Die These fasst die ersten Untersuchungen zum Pawlowsch`-Instrumentellen Transfer in alkoholabhängigen (AA) Patienten zusammen. Es ist bekannt, dass kontextuelle Umgebungsreize Verhalten beeinflussen. Tier- und Humanstudien haben gezeigt, dass positive Pawlowsche Reize instrumentelles Antwortverhalten verstärken und negative Pawlowsche Reize dieses reduzieren (PIT-Effekt). Bei Abhängigkeit wird angenommen, dass dieser Mechanismus relevant für Rückfall ist, da z.B. drogenassoziierte Reize bei Patienten im Vergleich zu Kontrollen erhöhtes Verlagen und funktionelle Aktivität in Belohnungsarealen auslösen. In Tier- und Humanstudien wurden stärkere PIT-Effekte vor allem mit funktioneller Aktivierung im Nucleus Accumbens (NAcc) beobachtet. Weiterhin zeigten sich bei Probanden mit stärkerem PIT-Effekt und bei AA Patienten erhöhte Impulsivitätswerte. Die PIT-Aufgabe besteht aus 3 Hauptteilen: i) Instrumentelle Konditionierung, ii) Pawlowsche Konditionierung, iii) Transfer mit Pawlowschen oder alkoholassoziierten Kontextstimuli. Impulsives Auswahlverhalten wurde durch die delay discounting Aufgabe erhoben. Es zeigten sich signifikant stärkere PIT-Effekte mit Pawlowschen Kontextreizen in AA Patienten im Vergleich zu Kontrollen mit funktioneller Aktivierung im NAcc, die zur Rückfallvorhersage beitrug. Der Transfer mit alkoholassoziierten Kontextreizen bewirkte eine signifikante Reduktion des instrumentellen Antwortverhaltens mit neuronalem Korrelat im NAcc nur bei abstinenten Patienten. Impulsives Auswahlverhalten und PIT hingen nur bei Patienten positiv zusammen. Die Studien lassen darauf schließen, dass PIT ein für Rückfall wichtiger Mechanismus ist mit funktionellem Korrelat im NAcc, der sich für motivationale Prozesse als auch als Salienzsignal relevant gezeigt hat. Die Subgruppe von hoch impulsiven Patienten ist im Besonderen durch Kontextreize im instrumentellen Antwortverhalten beeinflussbar, daher sollte ihr besondere Aufmerksamkeit bei Interventionen zukommen. / This thesis summarizes the first Pavlovian-to-instrumental transfer (PIT) studies in alcohol-dependent (AD) patients. Contextual stimuli are known to influence our behavior. Animal and human studies showed that positive Pavlovian stimuli enhance and negative Pavlovian stimuli reduce instrumental behavior (PIT effect). This mechanism might be relevant for relapse risk, as drug-associated stimuli have shown to enhance e.g. craving and functional activation in reward-related brain areas in patients compared to controls. In animal and human studies enhanced PIT effects were associated with activation particularly in the nucleus accumbens (NAcc). Moreover, control subjects with stronger PIT effects and AD patients were more impulsive on different facets of impulsivity. The PIT task consists of three main parts: i) instrumental conditioning, ii) Pavlovian conditioning, iii) transfer with Pavlovian background stimuli and instrumental task in the foreground (nondrug-related PIT: Pavlovian contextual cues; drug-related PIT: alcohol-related contextual cues). Choice impulsivity was measured by delay discounting task. We observed significantly enhanced nondrug-related PIT effects in AD patients compared to controls with a functional activation in the NAcc being predictive for relapse. Regarding drug-related PIT effects, we observed significantly reduced instrumental behavior during alcohol-related backgrounds with neural correlates in the NAcc in abstainers only. Choice impulsivity was positively related to PIT in AD patients only. Our data suggest that PIT is a mechanism contributing to relapse in AD patients with functional correlations within the NAcc, which based on our data is involved in motivation and attribution of salience. The subgroup of high impulsive patients is particularly susceptible for PIT effects, thus should be main target for intervention programs.

Pesquisas com drogas de abuso têm mostrado consistentemente que a apresentação de estímulos ambientais associados ao uso destas substâncias pode induzir comportamentos de busca e autoadministração das mesmas. Existe a hipótese de que o controle que estímulos ambientais adquirem sobre comportamentos de autoadministração e busca por drogas de abuso poderia ser influenciado tanto pela forma de administração da droga, autoadministração (administração ativa) ou heteroadministração (administração passiva), quanto pela contingência (operante ou respondente) em que a droga foi associada com tais estímulos. Foram formados trios compostos por um sujeito de cada grupo (CONT, ACOP e VEÍC) e realizados dois experimentos. Inicialmente os sujeitos de cada trio foram acoplados por meio de caixas experimentais separadas e expostos a tentativas discretas de apresentação dos estímulos luminosos, S1 e S2, simultaneamente. Como consequência do girar a roda operante na presença de S1 por um integrante do grupo CONT, este recebia uma infusão endovenosa de morfina (0,75 mg/kg), e simultaneamente os animais acoplados no trio recebiam uma infusão de morfina na mesma dose (grupo ACOP) ou de veículo (grupo VEÍC). Posteriormente, os sujeitos de todos os grupos foram treinados a pressionar uma barra por infusões endovenosas de morfina, sem contingência discriminativa programada alguma. Para esta fase, no experimento 1, S2 esteve presente durante as sessões experimentais, porém no experimento 2, nenhum S foi apresentado. Finalmente, os estímulos S1 e S2 foram apresentados em tentativas discretas, em condições de extinção. Os resultados mostram que, durante a extinção, o desempenho dos animais do grupo CONT, mas não os dos grupos ACOP e VEÍC, foi condizente com o treino recebido inicialmente (com 80% ou mais de respostas na barra em presença de S1), indicando que foi estabelecido controle discriminativo sobre a autoadministração de morfina no treino sob a contingência operante, mas não sob a respondente. Estes resultados sugerem que comportamentos de autoadministração e busca por drogas de abuso são influenciados tanto pela forma de administração da droga, quanto pelo tipo de contingência em que uma droga é associada com estímulos ambientais / Drug abuse research has consistently shown that presentation of a drug associated with environmental stimuli can induce drug-seeking and drug-administration behaviors. It has been hypothesized that stimuli control over drug-seeking and self-administration behaviors could be influenced by drug administrations nature, self-administration (active administration) or hetero-administration (passive administration), and also influenced by the drug-stimuli association contingency (operant or respondent). Animals were exposed to right jugular vein catheterization procedure. Groups Contingent (C), Yoked (Y) and Toked Saline (YS) were formed randomly after recovery. Yoked triads were formed with one subject from each group and two experiments were executed. Initially a discriminative training (light stimuli S1 and S2 discrete trials) was presented to triads. Each time C S group member turned an instrumental wheel in presence of S1, simultaneously, an intravenous morphine infusion (0.75 mg/kg) were administrated to that subject and yoked Y group member, as well as an intravenous saline infusion was administrated to yoked YS group member, in every triad. Afterward all subjects were individually trained to lever-press for an intravenous morphine infusion with no discrimination contingency programed. In this phase, S2 was presented through sessions in Experiment 1, while in Experiment 2 no S were presented. After achieving response stability, subjects were exposed to extinction sessions. Stimuli S1 and S2 discrete trials were presented but no consequences were programed for bar-press responses. Results show that only C groups performance was consistent with the previously received discriminative training (80% or more of bar-press responses in S1 presence) during extinction sessions, indicating that an operant training, but not a respondent training, successfully established morphine self-administration discriminative control. These results suggest that self-administration behaviors are in fact influenced by drugs administration nature and also by the drug-stimuli association contingency