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1.
Life Sci ; 245: 117386, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006528

RESUMO

AIMS: Steroid receptor coactivator-1 (SRC-1) is a key coactivator for the efficient transcriptional activity of steroids in the regulation of hippocampal functions. However, the effect of SRC-1 on hippocampal memory processes remains unknown. Our aim was to investigate the roles of hippocampal SRC-1 in the consolidation and reconsolidation of contextual fear memory in mice. MAIN METHODS: Contextual fear conditioning paradigm was constructed in adult male C57BL/6 mice to examine the fear learning and memory processes. Adeno-associated virus (AAV) vector-mediated RNA interference (RNAi) was infused into hippocampus to block hippocampal SRC-1 level. Immunofluorescent staining was used to detect the efficiency of transfection. High plus maze and open field test were used to determine anxiety and locomotor activity. Western blot analyses were used to detect the expression of SRC-1 and synaptic proteins in the hippocampus. KEY FINDINGS: We first showed that the expression of SRC-1 was regulated by fear conditioning training in a time-dependent manner, and knockdown of SRC-1 impaired contextual fear memory consolidation without affecting innate anxiety or locomotor activity. In addition, hippocampal SRC-1 was also regulated by the retrieval of contextual fear memory, and downregulation of SRC-1 disrupted fear memory reconsolidation. Moreover, knockdown of SRC-1 reversed the increased GluR1 and PSD-95 levels induced by contextual fear memory retrieval. SIGNIFICANCE: Our data indicate that hippocampal SRC-1 is required for the consolidation and reconsolidation of contextual fear memory, and SRC-1 may be a potential therapeutic target for mental disorders that are involved in hippocampal memory dysfunction.


Assuntos
Medo/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Memória/efeitos dos fármacos , Coativador 1 de Receptor Nuclear/antagonistas & inibidores , Animais , Western Blotting , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Clássico/fisiologia , Medo/fisiologia , Medo/psicologia , Imunofluorescência , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Coativador 1 de Receptor Nuclear/fisiologia
2.
Nat Commun ; 11(1): 471, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980655

RESUMO

Astrocytes may function as mediators of the impact of noradrenaline on neuronal function. Activation of glial α1-adrenergic receptors triggers rapid astrocytic Ca2+ elevation and facilitates synaptic plasticity, while activation of ß-adrenergic receptors elevates cAMP levels and modulates memory consolidation. However, the dynamics of these processes in behaving mice remain unexplored, as do the interactions between the distinct second messenger pathways. Here we simultaneously monitored astrocytic Ca2+ and cAMP and demonstrate that astrocytic second messengers are regulated in a temporally distinct manner. In behaving mice, we found that while an abrupt facial air puff triggered transient increases in noradrenaline release and large cytosolic astrocytic Ca2+ elevations, cAMP changes were not detectable. By contrast, repeated aversive stimuli that lead to prolonged periods of vigilance were accompanied by robust noradrenergic axonal activity and gradual sustained cAMP increases. Our findings suggest distinct astrocytic signaling pathways can integrate noradrenergic activity during vigilance states to mediate distinct functions supporting memory.


Assuntos
Nível de Alerta/fisiologia , Astrócitos/fisiologia , Norepinefrina/fisiologia , Sistemas do Segundo Mensageiro/fisiologia , Animais , Sinalização do Cálcio/fisiologia , Condicionamento Clássico/fisiologia , AMP Cíclico/metabolismo , Medo/fisiologia , Corantes Fluorescentes , Locus Cerúleo/citologia , Locus Cerúleo/fisiologia , Memória/fisiologia , Camundongos , Plasticidade Neuronal/fisiologia , Lobo Parietal/citologia , Lobo Parietal/fisiologia , Receptores Adrenérgicos/fisiologia
3.
Nat Commun ; 10(1): 5826, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862876

RESUMO

A Pavlovian bias to approach reward-predictive cues and avoid punishment-predictive cues can conflict with instrumentally-optimal actions. Here, we propose that the brain arbitrates between Pavlovian and instrumental control by inferring which is a better predictor of reward. The instrumental predictor is more flexible; it can learn values that depend on both stimuli and actions, whereas the Pavlovian predictor learns values that depend only on stimuli. The arbitration theory predicts that the Pavlovian predictor will be favored when rewards are relatively uncontrollable, because the additional flexibility of the instrumental predictor is not useful. Consistent with this hypothesis, we find that the Pavlovian approach bias is stronger under low control compared to high control contexts.


Assuntos
Encéfalo/fisiologia , Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Modelos Psicológicos , Recompensa , Adulto , Teorema de Bayes , Humanos
4.
Nat Neurosci ; 22(12): 2050-2059, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31768054

RESUMO

Affective learning and memory are essential for daily behavior, with both adaptive and maladaptive learning depending on stimulus-evoked activity in the amygdala circuitry. Behavioral studies further suggest that post-association offline processing contributes to memory formation. Here we investigated spike sequences across simultaneously recorded neurons while monkeys learned to discriminate between aversive and pleasant tone-odor associations. We show that triplets of neurons exhibit consistent temporal sequences of spiking activity that differed from firing patterns of individual neurons and pairwise correlations. These sequences occurred throughout the long post-trial period, contained valence-related information, declined as learning progressed and were selectively present in activity evoked by the recent pairing of a conditioned stimulus with an unconditioned stimulus. Our findings reveal that temporal sequences across neurons in the primate amygdala serve as a coding mechanism and might aid memory formation through the rehearsal of the recently experienced association.


Assuntos
Tonsila do Cerebelo/fisiologia , Memória/fisiologia , Neurônios/fisiologia , Potenciais de Ação/fisiologia , Animais , Condicionamento Clássico/fisiologia , Aprendizagem por Discriminação/fisiologia , Macaca fascicularis , Fatores de Tempo
5.
Acta Psychol (Amst) ; 201: 102952, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31733436

RESUMO

Interval timing, the ability to discern the duration of an event, is integral to appropriately navigating the world, from crossing the road to catching a ball. Several features of an event can affect its perceived duration, for example it has previously been shown that a large stimulus is perceived to last longer than a small stimulus. In the current article, participants performed either a Go/No-Go or variable foreperiod task prior to performing a temporal bisection task. In both the Go/No-Go and variable foreperiod tasks, participants learned an association between a particular response and a particular stimulus. Subsequently, the perceived duration of these stimuli was tested in a temporal bisection task. Our findings indicated that associating a stimulus with response inhibition (i.e. a No-Go stimulus) decreased perceived duration compared to a stimulus associated with a response (a Go stimulus). Associating a stimulus with either a short or long foreperiod, on the other hand, did not affect perceived duration. We relate this finding back to the coding efficiency theory and the processing principle. A No-Go stimulus requires more cognitive processing than a Go stimulus and would thus be predicted to increase, rather than decrease, perceived duration in both these time perception theories. Finally, we suggest how our findings might be used in future investigations of interval timing.


Assuntos
Aprendizagem por Associação/fisiologia , Condicionamento Clássico/fisiologia , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Percepção do Tempo/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
6.
Nat Neurosci ; 22(12): 2000-2012, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31712775

RESUMO

Acquisition and extinction of learned fear responses utilize conserved but flexible neural circuits. Here we show that acquisition of conditioned freezing behavior is associated with dynamic remodeling of relative excitatory drive from the basolateral amygdala (BLA) away from corticotropin releasing factor-expressing (CRF+) centrolateral amygdala neurons, and toward non-CRF+ (CRF-) and somatostatin-expressing (SOM+) neurons, while fear extinction training remodels this circuit back toward favoring CRF+ neurons. Importantly, BLA activity is required for this experience-dependent remodeling, while directed inhibition of the BLA-centrolateral amygdala circuit impairs both fear memory acquisition and extinction memory retrieval. Additionally, ectopic excitation of CRF+ neurons impairs fear memory acquisition and facilities extinction, whereas CRF+ neuron inhibition impairs extinction memory retrieval, supporting the notion that CRF+ neurons serve to inhibit learned freezing behavior. These data suggest that afferent-specific dynamic remodeling of relative excitatory drive to functionally distinct subcortical neuronal output populations represents an important mechanism underlying experience-dependent modification of behavioral selection.


Assuntos
Complexo Nuclear Basolateral da Amígdala/fisiologia , Núcleo Central da Amígdala/fisiologia , Medo/fisiologia , Ácido Glutâmico/fisiologia , Animais , Condicionamento Clássico/fisiologia , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Potenciais Pós-Sinápticos Excitadores/fisiologia , Extinção Psicológica/fisiologia , Reação de Congelamento Cataléptica/fisiologia , Camundongos Transgênicos , Vias Neurais/fisiologia , Somatostatina/genética , Somatostatina/metabolismo
7.
Exp Psychol ; 66(4): 257-265, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31530250

RESUMO

It is generally assumed that relational knowledge is the foundation of higher cognition such as (analogical and conditional) reasoning, language, the use of relational categories, and planning. Dual-system models (e.g., Kahneman, 2011) that divide the realm of cognition into two systems with opposing properties (e.g., fast vs. slow, intentional vs. unintentional, conscious vs. unconscious, associative vs. propositional) foster the view that other psychological phenomena are not relational in nature. In this paper, I argue that the impact of relational knowledge is more widespread than dual-system models imply. More specifically, I review evidence suggesting that also Pavlovian conditioning, implicit evaluation, and habitual responding are mediated by relational knowledge. Considering the idea that relational knowledge underlies also fast, unintentional, unconscious, and seemingly associative psychological phenomena is not only theoretically important but also reveals new opportunities for influencing thinking and behavior.


Assuntos
Cognição/fisiologia , Condicionamento Clássico/fisiologia , Humanos , Resolução de Problemas
8.
Psychopharmacology (Berl) ; 236(8): 2373-2388, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31367850

RESUMO

In the context of Pavlovian conditioning, two types of behaviour may emerge within the population (Flagel et al. Nature, 469(7328): 53-57, 2011). Animals may choose to engage either with the conditioned stimulus (CS), a behaviour known as sign-tracking (ST) which is sensitive to dopamine inhibition for its acquisition, or with the food cup in which the reward or unconditioned stimulus (US) will eventually be delivered, a behaviour known as goal-tracking (GT) which is dependent on dopamine for its expression only. Previous work by Lesaint et al. (PLoS Comput Biol, 10(2), 2014) offered a computational explanation for these phenomena and led to the prediction that varying the duration of the inter-trial interval (ITI) would change the relative ST-GT proportion in the population as well as phasic dopamine responses. A recent study verified this prediction, but also found a rich variance of ST and GT behaviours within the trial which goes beyond the original computational model. In this paper, we provide a computational perspective on these novel results.


Assuntos
Simulação por Computador , Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Objetivos , Animais , Dopamina/metabolismo , Masculino , Motivação , Recompensa , Fatores de Tempo
9.
J Exp Psychol Anim Learn Cogn ; 45(4): 446-463, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31368765

RESUMO

Three experiments with rats assessed the effects of introducing predictive ambiguity by reversing a Pavlovianly trained discrimination on subsequent context and temporal conditioning. The experience of discrimination reversal did not facilitate context conditioning when the food was presented on a variable time schedule (Experiment 1a). However, in Experiment 1b, discrimination reversal enhanced subsequent learning of a fixed temporal interval associated with unsignaled food presentation in comparison with consistent training. In Experiment 2, temporal discrimination after reversal and consistent training was compared with a naïve control. The experience of discrimination facilitated subsequent temporal conditioning with respect to the naïve control, and discrimination reversal enhanced temporal conditioning even further. In Experiment 3, reversal enhanced learning of the fixed temporal interval, regardless of whether it was relatively short or long (i.e., 30 s or 60 s). Results are discussed in terms of current associative theories of human and nonhuman conditioning and attention. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Comportamento Apetitivo/fisiologia , Condicionamento Clássico/fisiologia , Aprendizagem por Discriminação/fisiologia , Reversão de Aprendizagem/fisiologia , Percepção do Tempo/fisiologia , Animais , Condicionamento Operante/fisiologia , Feminino , Desempenho Psicomotor/fisiologia , Ratos , Ratos Wistar
10.
J Exp Psychol Anim Learn Cogn ; 45(4): 405-412, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31368766

RESUMO

Defensive responses to threatening events in the environment are displayed by a vast number of animals, both vertebrate and invertebrate. These defensive responses can be associated with salient neutral stimuli that are present along with the threatening stimulus. This is referred to as aversive conditioning. Animals with more simple nervous systems, such as Aplysia, C elegans, and Drosophila, have facilitated identification of some the physiological processes that support aversive conditioning. Perhaps even more basic information regarding the neurobiology of learning and memory may be gleaned from animals that have special characteristics not found in other species. Tardigrades, also known as "water bears," are microscopic eight-legged animals that live in various aquatic and terrestrial environments. They are known for their resilience to extreme conditions because of their ability to enter a cryptobiotic "tun" state during which they turn off their metabolism. Thus, tardigrades present an ideal model to study the metabolic requirements for memory storage. However, there is no prior research on tardigrade learning and memory. The purpose of this study was to demonstrate aversive conditioning in a tardigrade species, Dactylobiotus dispar. Associative learning was confirmed by numerous control conditions (unconditioned stimulus [US] only, conditional stimulus [CS] only, backward pairing, random pairing). Short-term memories were formed after a single pairing of the CS and US. This research introduces an important new animal model to the study of the neurobiology of aversive conditioning with important ramifications for understanding the metabolic influences on learning and memory. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Memória de Curto Prazo/fisiologia , Tardígrados/fisiologia , Animais , Modelos Animais
11.
J Exp Psychol Anim Learn Cogn ; 45(4): 485-501, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31368769

RESUMO

Conditioned responding extinguishes more slowly after partial (inconsistent) reinforcement than after consistent reinforcement. This Partial Reinforcement Extinction Effect (PREE) is usually attributed to learning about nonreinforcement during the partial schedule. An alternative explanation attributes it to any difference in the rate of reinforcement, arguing that animals can detect the change to nonreinforcement more quickly after a denser schedule than a leaner schedule. Experiments 1a and 1b compared extinction of magazine responding to a conditioned stimulus (CS) reinforced with 1 food pellet per trial and a CS reinforced with 2 pellets per trial. Despite the difference in reinforcement rate, there was no reliable difference in extinction. Both experiments did demonstrate the conventional PREE comparing a partial CS (50% reinforced) with a consistent CS. Experiments 2 and 3 tested whether the PREE depends specifically on learning about nonreinforced trials during partial reinforcement. Rats were trained with 2 CS configurations, A and AX. One was partially reinforced, the other consistently reinforced. When AX was partial and A consistent, responding to AX extinguished more slowly than to A. When AX was consistent and A was partial, there was no difference in their extinction. Therefore, pairing X with partial reinforcement allowed rats to show a PREE to AX that did not generalize to A. Pairing A with partial reinforcement meant that rats showed a PREE to A that generalized to AX. Thus, the PREE depends on learning about nonreinforced trials during partial reinforcement and is not because of any difference in per-trial probability of reinforcement. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Ratos Sprague-Dawley/anatomia & histologia , Animais , Condicionamento Operante/fisiologia , Extinção Psicológica/fisiologia , Feminino , Desempenho Psicomotor/fisiologia , Ratos , Esquema de Reforço
12.
Nat Commun ; 10(1): 3690, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31417086

RESUMO

Associative memory is the main type of learning by which complex organisms endowed with evolved nervous systems respond efficiently to certain environmental stimuli. It has been found in different multicellular species, from cephalopods to humans, but never in individual cells. Here we describe a motility pattern consistent with associative conditioned behavior in the microorganism Amoeba proteus. We use a controlled direct-current electric field as the conditioned stimulus, and a specific chemotactic peptide as the unconditioned stimulus. The amoebae are capable of linking two independent past events, generating persistent locomotion movements that can prevail for 44 min on average. We confirm a similar behavior in a related species, Metamoeba leningradensis. Thus, our results indicate that unicellular organisms can modify their behavior during migration by associative conditioning.


Assuntos
Amoeba/fisiologia , Aprendizagem por Associação/fisiologia , Condicionamento Clássico/fisiologia , Locomoção/fisiologia
13.
J Exp Psychol Anim Learn Cogn ; 45(4): 390-404, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31414879

RESUMO

Many theories of conditioning describe learning as a process by which stored information about the relationship between a conditioned stimulus (CS) and unconditioned stimulus (US) is progressively updated upon each occasion (trial) that the CS occurs with, or without, the US. These simple trial-based descriptions can provide a powerful and efficient means of extracting information about the correlation between 2 events, but they fail to explain how animals learn about the timing of events. This failure has motivated models of conditioning in which animals learn continuously, either by explicitly representing temporal intervals between events or by sequentially updating an array of associations between temporally distributed elements of the CS and US. Here, I review evidence that some aspects of conditioning are not the consequence of a continuous learning process but reflect a trial-based process. In particular, the way that animals learn about the absence of a predicted US during extinction suggests that they encode and remember trials as single complete episodes rather than as a continuous experience of unfulfilled expectation of the US. These memories allow the animal to recognize repeated instances of nonreinforcement and encode these as a sequence that, in the case of a partial reinforcement schedule, can become associated with the US. The animal is thus able to remember details about the pattern of a CS's reinforcement history, information that affects how long the animal continues to respond to the CS when all reinforcement ceases. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Aprendizagem por Associação/fisiologia , Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Animais
14.
Nat Commun ; 10(1): 3591, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399570

RESUMO

Practice improves perception and enhances neural representations of trained visual stimuli, a phenomenon known as visual perceptual learning (VPL). While attention to task-relevant stimuli plays an important role in such learning, Pavlovian stimulus-reinforcer associations are sufficient to drive VPL, even subconsciously. It has been proposed that reinforcement facilitates perceptual learning through the activation of neuromodulatory centers, but this has not been directly confirmed in primates. Here, we paired task-irrelevant visual stimuli with microstimulation of a dopaminergic center, the ventral tegmental area (VTA), in macaques. Pairing VTA microstimulation with a task-irrelevant visual stimulus increased fMRI activity and improved classification of fMRI activity patterns selectively for the microstimulation-paired stimulus. Moreover, pairing VTA microstimulation with a task-irrelevant visual stimulus improved the subject's capacity to discriminate that stimulus. This is the first causal demonstration of the role of neuromodulatory centers in VPL in primates.


Assuntos
Condicionamento Clássico/fisiologia , Macaca mulatta/fisiologia , Área Tegmentar Ventral/fisiologia , Percepção Visual/fisiologia , Animais , Estimulação Encefálica Profunda/instrumentação , Estimulação Encefálica Profunda/métodos , Neuroestimuladores Implantáveis , Imagem por Ressonância Magnética , Masculino , Microeletrodos , Estimulação Luminosa/instrumentação , Estimulação Luminosa/métodos , Área Tegmentar Ventral/diagnóstico por imagem
15.
Behav Ther ; 50(5): 967-977, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31422851

RESUMO

In exposure therapy, the client can either be confronted with the fear-eliciting situations in a hierarchical way or in a random way. In the current study we developed a procedure to investigate the effects of hierarchical versus random exposure on long-term fear responding in the laboratory. Using a fear conditioning procedure, one stimulus (CS+) was paired with an electric shock (US), whereas another stimulus was not paired with the shock (CS-). The next day, participants underwent extinction training including presentations of the CS-, CS+ and a series of morphed stimuli between the CS- and CS+. In the hierarchical extinction condition (HE; N = 32), participants were first presented with the CS-, subsequently with the morph most similar to the CS-, then with the morph most similar to that one, and so forth, until reaching the CS+. In the random extinction condition (RE; N = 32), the same stimuli were presented but in a random order. Fear responding to the CS+, CS- and a new generalization stimulus (GS) was measured on the third day. Higher expectancy violation, t(62) = -2.67, p = .01, physiological arousal, t(62) = -2.08, p = .04, and variability in US-expectancy ratings, t(62) = -2.25, p = .03, were observed in the RE condition compared to the HE condition, suggesting the validity of this novel procedure. However, no differences between the RE and HE condition were found in fear responding as tested one day later, F(1, 62) < 1. In conclusion, we did not find evidence for differential long-term fear responding in modeling hierarchical versus random exposure in Pavlovian fear extinction.


Assuntos
Atenção/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Medo/fisiologia , Generalização do Estímulo/fisiologia , Adulto , Feminino , Resposta Galvânica da Pele , Humanos , Terapia Implosiva , Masculino
16.
Acta Psychol (Amst) ; 199: 102894, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31349030

RESUMO

Human beings possess the adaptive ability to apply experiential knowledge to new situations. Although this generalization capability has been demonstrated in fear and reward learning, it remains unclear whether it extends to analgesic and hyperalgesic pain responses. Here, we conducted two experiments (total n = 104) to test the generalization effects of placebo analgesia and nocebo hyperalgesia. The first experiment, using a category-based conditioning paradigm in which two categories of images were used as acquisition stimuli, assessed whether pain perception can be generalized to never-seen pictures of the same category in the generalization phase. The second experiment adopted a single stimulus for each category as CS to further examine the generalization effects after learning a single exemplar. Pain ratings showed that participants reported higher pain or lower pain when the pain was preceded by novel stimuli that were conceptually similar to the previously conditioned stimuli, suggesting a generalization of analgesic and hyperalgesic pain modulation effects. These results provide novel evidence that analgesic and hyperalgesic effects on pain perception can be generalized to conceptually similar new items.


Assuntos
Condicionamento Clássico/fisiologia , Aprendizagem/fisiologia , Percepção da Dor/fisiologia , Estimulação Luminosa/métodos , Adulto , Medo/fisiologia , Medo/psicologia , Feminino , Humanos , Masculino , Efeito Nocebo , Medição da Dor/métodos , Medição da Dor/psicologia , Efeito Placebo , Adulto Jovem
17.
Brain Stimul ; 12(6): 1448-1455, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31289015

RESUMO

BACKGROUND: Drug use causes the formation of strong cue/reward associations which persist long after cessation of drug-taking and contribute to the long-term risk of relapse. Extinguishing these associations may reduce cue-induced craving and relapse. Previously, we found that pairing vagus nerve stimulation (VNS) with extinction of cocaine self-administration reduces cue-induced reinstatement; however, it remains unclear whether this was primarily caused by extinguishing the context, the instrumental response, or both. OBJECTIVE: Hypothesis: We hypothesized that VNS can facilitate the extinction of both contextual cues and instrumental responding. METHODS: Extinction of context was first tested using Pavlovian conditioned place preference (CPP). Next, the impact of VNS on the extinction of instrumental responding was assessed under ABA and AAA context conditions. In each extinction context separate groups of rats were either provided the opportunity to perform the instrumental response, or the levers were retracted for the duration of extinction training. Reinstatement was induced by reintroduction of the conditioned stimuli and/or the drug-paired context. Data were analyzed using one-way or two-way repeated measures ANOVAs. RESULTS: VNS during extinction reduced reinstatement of CPP. VNS also reduced cue- and context-induced reinstatement of the instrumental response under both AAA and ABA conditions. The subjects' ability to engage with the lever during extinction was crucial for this effect. P values < 0.05 were considered significant. CONCLUSIONS: Craving occurs in response to a range of conditioned stimuli and contexts; VNS may improve outcomes of behavioral therapy by facilitating extinction of both an instrumental response and/or contextual cues.


Assuntos
Cocaína/administração & dosagem , Condicionamento Clássico/fisiologia , Fissura/fisiologia , Extinção Psicológica/fisiologia , Estimulação do Nervo Vago/métodos , Animais , Condicionamento Clássico/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Condicionamento Operante/fisiologia , Fissura/efeitos dos fármacos , Sinais (Psicologia) , Masculino , Ratos , Ratos Sprague-Dawley , Recompensa , Autoadministração , Estimulação do Nervo Vago/tendências
18.
Soc Cogn Affect Neurosci ; 14(7): 769-775, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31309971

RESUMO

Previous research has linked sensation seeking with a heightened risk for drug abuse and other risk-taking behavior. As appetitive conditioning presents a model for the etiology and maintenance of addictive behavior, investigating sensation seeking in a classical conditioning paradigm might elucidate possible pathways toward addiction within this model. Furthermore, the theoretical concept underlying sensation seeking proposes a negative relationship between reward processing and sensation seeking in only moderately arousing situations, which has been neglected by previous research. This study aimed to investigate this inverse relationship in moderately stimulating situations entailing reward processing using functional magnetic resonance imaging. Subjects (N = 38) participated in a classical conditioning paradigm in which a neutral stimulus (CS+) was repeatedly paired with a monetary reward, while another neutral stimulus (CS-) was not. Imaging results revealed a negative relationship between sensation seeking and neural responses in the insula, amygdala and nucleus accumbens during the early phase and in the dorsal anterior cingulate cortex during the late phase of conditioning. These findings suggest reduced reward learning and consequently diminished processing of outcome expectancy in appetitive conditioning in subjects with high sensation seeking scores. The results are discussed with respect to clinical implications.


Assuntos
Condicionamento Clássico/fisiologia , Núcleo Accumbens/fisiologia , Sensação/fisiologia , Adulto , Tonsila do Cerebelo/fisiopatologia , Feminino , Humanos , Aprendizagem/fisiologia , Imagem por Ressonância Magnética , Masculino , Recompensa , Adulto Jovem
19.
Behav Processes ; 166: 103898, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31265879

RESUMO

Three experiments tested the effect of experiencing extinction on learning about a differential conditioned inhibitor that was trained as an excitor. A human predictive learning task was used in which participants had to evaluate the probability of different colored fertilizers (Cues) leading plants to flourish or not (Outcome). Experiment 1 found that presenting the target cue without outcome while other cues were followed by the outcome made the target cue a conditioned inhibitor, passing both, retardation (Experiment 1a) and summation (Experiment 1b) tests of conditioned inhibition. Subsequent extinction of a different cue facilitated reversing the relationship between the conditioned inhibitor and the outcome regardless of whether the situation could be solved by using simple rules (Experiment 2) or not (Experiment 3). Results are discussed in terms of attentional theories that suggest extinction produces a nonspecific increase in attention that facilitates learning.


Assuntos
Aprendizagem por Associação/fisiologia , Condicionamento Clássico/fisiologia , Extinção Psicológica/fisiologia , Adolescente , Adulto , Atenção/fisiologia , Sinais (Psicologia) , Feminino , Humanos , Masculino , Adulto Jovem
20.
Psychopharmacology (Berl) ; 236(12): 3465-3476, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31286155

RESUMO

RATIONALE: Experimental tasks that demonstrate alcohol-related attentional bias typically expose participants to single-stimulus targets (e.g. addiction Stroop, visual probe, anti-saccade task), which may not correspond fully with real-world contexts where alcoholic and non-alcoholic cues simultaneously compete for attention. Moreover, alcoholic stimuli are rarely matched to other appetitive non-alcoholic stimuli. OBJECTIVES: To address these limitations by utilising a conjunction search eye-tracking task and matched stimuli to examine alcohol-related attentional bias. METHODS: Thirty social drinkers (Mage = 19.87, SD = 1.74) were asked to detect whether alcoholic (beer), non-alcoholic (water) or non-appetitive (detergent) targets were present or absent amongst a visual array of matching and non-matching distractors. Both behavioural response times and eye-movement dwell time were measured. RESULTS: Social drinkers were significantly quicker to detect alcoholic and non-alcoholic appetitive targets relative to non-appetitive targets in an array of matching and mismatching distractors. Similarly, proportional dwell time was lower for both alcoholic and non-alcoholic appetitive distractors relative to non-appetitive distractors, suggesting that appetitive targets were relatively easier to detect. CONCLUSIONS: Social drinkers may exhibit generalised attentional bias towards alcoholic and non-alcoholic appetitive cues. This adds to emergent research suggesting that the mechanisms driving these individual's attention towards alcoholic cues might 'spill over' to other appetitive cues, possibly due to associative learning.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Viés de Atenção/fisiologia , Cerveja , Sinais (Psicologia) , Movimentos Oculares/fisiologia , Estimulação Luminosa/métodos , Adolescente , Adulto , Atenção/fisiologia , Condicionamento Clássico/fisiologia , Feminino , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Distribuição Aleatória , Tempo de Reação/fisiologia , Adulto Jovem
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