The effects of intensity of the unconditioned stimulus (US) on the acquisition and extinction of the conditioned emotional response (CER) in rats were investigated. The US intensities studied were 0.28, 0.49, 0.85, 1.55, and 2.91 ma. Both acquisition and extinction of the CER were found to be monotonic functions of US intensity, with the higher US intensities producing more rapid acquisition and more resistance to extinction. The lowest shock intensity failed to produce suppression. The 0.49 ma. subjects typically showed a partial recovery of normal operant behavior after development of a fairly profound CER. The results were interpreted as consistent wth the supposition that the CER is acquired in accordance with Pavlovian laws of classical conditioning. / Thesis / Master of Arts (MA)

The effects of intensity of the unconditioned stimulus (US) on the acquisition and extinction of the conditioned emotional response (CER) in rats were investigated. The US intensities studied were 0.28, 0.49, 0.85, 1.55, and 2.91 ma. Both acquisition and extinction of the CER were found to be monotonic functions of US intensity, with the higher US intensities producing more rapid acquisition and more resistance to extinction. The lowest shock intensity failed to produce suppression. The 0.49 ma. subjects typically showed a partial recovery of normal operant behavior after development of a fairly profound CER. The results were interpreted as consistent with the supposition that the CER is acquired in accordance with Pavlovian laws of classical conditioning. / Thesis / Master of Arts (MA)

In the present study, footshock, which produces a powerful aversive emotional response was used in a Pavlovian conditioning experiment as an unconditioned stimulis (UCS), and was paired with the presentation of a light used as a conditioned stimulis (CS). There is an accumulation of evidence that supports the assertion that dopaminergic (DA) neurons within the ventral tegmental area (VTA) are active in processes that contribute to the amygdala-based circuitry involved in regulating emotionally salient responses. To build upon findings implicating VTA DA, excitatory glutamate (Glu), NMDA and AMPA receptors, were examined with respect to their role in Pavlovian conditioned fear responding. Fear potentiated startle (FPS) was used to assess the effects of intra-VTA infused AP5, and intra-VTA infused CNQX on conditioned fear responding in laboratory rats. The administration of the NMDA receptor antagonist AP5 (at 1.0, 2.5, and 5.0ug doses), blocked the ability of a conditioned stimulus (CS) previously paired with footshock to become conditioned to the UCS. Similarly, administration of the AMPA receptor antagonist CNQX (at 1.0, 2.5, 5.0ug doses), inhibited the ability of the CS to become conditioned to the UCS. The results of this study indicate the VTA is an important site for synaptic modifications associated with fear learning, and that activation of excitatory Glutamatergic receptors in the VTA play a necessary part of the processing underlying fear conditioning. Measures of shock reactivity demonstrated that the infusion of AP5 and CNQX into the VTA did not inhibit baseline startle amplitudes. The administration of AP5 and CNQX did not suppress the perception of footshock as an aversive stimulus. This study provides further definition to established knowledge surrounding the neural processes whereby neutral environmental cues gain negative emotional salience as occurs in fear conditioning. It was hypothesised that the action of excitatory glutamatergic transmission within the VTA acts on NMDA and AMPA receptors is to assist in the acquisition of Pavlovian conditioned fear, possibly through the same synaptic mechanisms that govern LTP.

Tidigare studier har visat på sambandet mellan oräddhet, psykopati, aggressivitet och antisocialt beteende. Denna studie undersökte fenotypiska och genetiska relationer mellan komponenter i the skin conductance fear conditioning task och i psykopatiska personlighetsdrag. Data hämtades från den longitudinella studien; Tvillingstudie om riskfaktorer för antisocialt beteende (RFAB) vid University of Southern California och data från pågående tillfälle 5 inkluderades i studien. Resultatet visade på betydelsen av både genetiska och icke-gemensamma miljö influenser förklarade variansen i obetingad respons. I överensstämmelse med tidigare forskning visade resultaten att individer som visade på högre nivåer av manipulativt och svekfullt beteende också uppvisade större brister i rädslobetingelser. / Previous studies have shown a relationship among fearlessness, psychopathy, aggression and antisocial behavior. This study examined the phenotypic and genetic relationships among components of the skin conductance fear conditioning task and psychopathic personality traits. Data were retrieved from a longitudinal study; the Twin Study of Risk Factor for Antisocial Behavior at the University of Southern California. The present study included data from the ongoing Wave 5. Results indicated the importance of both genetic and non-shared environmental influences in explaining the variance in the unconditioned response. Consistent with previous research, the results showed that individuals who displayed higher levels of manipulative and deceitful traits also showed deficits in fear conditioning.

In the present study, footshock, which produces a powerful aversive emotional response was used in a Pavlovian conditioning experiment as an unconditioned stimulis (UCS), and was paired with the presentation of a light used as a conditioned stimulis (CS). There is an accumulation of evidence that supports the assertion that dopaminergic (DA) neurons within the ventral tegmental area (VTA) are active in processes that contribute to the amygdala-based circuitry involved in regulating emotionally salient responses. To build upon findings implicating VTA DA, excitatory glutamate (Glu), NMDA and AMPA receptors, were examined with respect to their role in Pavlovian conditioned fear responding. Fear potentiated startle (FPS) was used to assess the effects of intra-VTA infused AP5, and intra-VTA infused CNQX on conditioned fear responding in laboratory rats. The administration of the NMDA receptor antagonist AP5 (at 1.0, 2.5, and 5.0ug doses), blocked the ability of a conditioned stimulus (CS) previously paired with footshock to become conditioned to the UCS. Similarly, administration of the AMPA receptor antagonist CNQX (at 1.0, 2.5, 5.0ug doses), inhibited the ability of the CS to become conditioned to the UCS. The results of this study indicate the VTA is an important site for synaptic modifications associated with fear learning, and that activation of excitatory Glutamatergic receptors in the VTA play a necessary part of the processing underlying fear conditioning. Measures of shock reactivity demonstrated that the infusion of AP5 and CNQX into the VTA did not inhibit baseline startle amplitudes. The administration of AP5 and CNQX did not suppress the perception of footshock as an aversive stimulus. This study provides further definition to established knowledge surrounding the neural processes whereby neutral environmental cues gain negative emotional salience as occurs in fear conditioning. It was hypothesised that the action of excitatory glutamatergic transmission within the VTA acts on NMDA and AMPA receptors is to assist in the acquisition of Pavlovian conditioned fear, possibly through the same synaptic mechanisms that govern LTP.

No description available.

The aim of this research is to expand the framework of contemporary conflict resolution by constructing a complementary relationship between Western epistemologies and a Buddhist epistemology. Despite its evolution and development through self-reflexivity and self-critique, contemporary conflict resolution established upon Western epistemologies has confined the understanding of human mind to social/cultural orientations and left a comprehensive and qualitative analysis of the potential of individual human mind underdeveloped. Buddhist epistemology, the central theme of which is to address human suffering that is mainly psychological and subjective, makes a critical analysis of human subjectivity in terms of how it can be become a root cause of suffering including conflict and how it can be addressed by gaining an insight into the social/cultural construction of human subjectivity. The argument of the thesis is that when a socially/culturally-oriented view of human mind and a deeper and more profound view of human mind are combined together, we can engage in a qualitatively richer and deeper analysis of the psychological and subjective dynamics of conflict resolution.

Several variables have been shown to influence resistance to change including rate, magnitude, and delay to reinforcement (Nevin, 1974). One variable that has not been studied with humans concerns the evaluation of resistance to change with unconditioned and conditioned reinforcers. In Experiment 1 (Resistance to Extinction Assessment), 5 participants' behaviors were reinforced during a baseline phase on a mult VI 30 s VI 30 s schedule with either a conditioned (i.e., token) or unconditioned reinforcer (i.e., food). Following equal reinforcement rates across components, extinction was introduced as a disruptor. All participants showed greater resistance to extinction in the component associated with conditioned reinforcers than unconditioned reinforcers. In Experiment 2 (Varied Distractors Assessment), 4 participants experienced a baseline phase the same as Experiment 1 (i.e., mult VI 30 s VI 30 s). Each participant was then exposed to prefeeding and distraction as disruptors in separate analyses. Results showed that behaviors were more resistant to distraction with conditioned than unconditioned reinforcers, similar to Experiment 1. However, when prefeeding disrupted responding, greater resistance to change was observed with unconditioned reinforcers than conditioned reinforcers. Implications of the results are discussed.

The aim of this research is to expand the framework of contemporary conflict resolution by constructing a complementary relationship between Western epistemologies and a Buddhist epistemology. Despite its evolution and development through self-reflexivity and self-critique, contemporary conflict resolution established upon Western epistemologies has confined the understanding of human mind to social/cultural orientations and left a comprehensive and qualitative analysis of the potential of individual human mind underdeveloped. Buddhist epistemology, the central theme of which is to address human suffering that is mainly psychological and subjective, makes a critical analysis of human subjectivity in terms of how it can be become a root cause of suffering including conflict and how it can be addressed by gaining an insight into the social/cultural construction of human subjectivity. The argument of the thesis is that when a socially/culturally-oriented view of human mind and a deeper and more profound view of human mind are combined together, we can engage in a qualitatively richer and deeper analysis of the psychological and subjective dynamics of conflict resolution.

O desequilíbrio da homeostase emocional tem sido considerado como um mecanismo subjacente aos transtornos de ansiedade e humor. Em fêmeas, as alterações na secreção hormonal durante as diferentes fases do ciclo estral podem ser a base das alterações na reatividade emocional a eventos estressantes. Estudos comportamentais sobre diferenças sexuais no processamento das emoções mostram resultados conflitantes em fêmeas devido às dificuldades na seleção dos melhores modelos animais para testar as diferenças associadas ao ciclo estral. Uma vez que os testes comportamentais foram desenvolvidos em animais do sexo masculino, eles podem não ser apropriados para fêmeas. O presente estudo foi desenvolvido para contribuir nessa linha de pesquisa usando diferentes modelos de animais de medo incondicionado e condicionado, considerando as diferentes fases do ciclo estral das ratas. Comparou-se o desempenho de machos e fêmeas nas quatro fases do ciclo estral em dois testes de medo incondicionado: o switch-off, em que ratos cruzam uma caixa vai-e-vem para desligar uma luz aversiva, e o registro de vocalizações ultrassônicas (VUSs) a 22 kHz emitidos por animais sob o estresse agudo de restrição. Nos testes de medo condicionado, registrou-se o sobressalto potencializado pelo medo e a resposta decongelamento a um contexto aversivo. Em ambos os testes de medo condicionado, a reatividade emocional não se mostrou diferente entre os sexos. No entanto, no que diz respeito ao medo incondicionado, ratas em diestro tardio apresentaram maior reatividade emocional em desligar a luz intensa e maior emissão de VUSs em resposta à restrição em relação a outras fases do ciclo. Estes achados sugerem que o perfil hormonal durante a fase do diestro 2 pode aumentar a reatividade emocional de ratas frente a estímulos inatos, porém não àqueles aprendidos. / Dysfunctional emotional regulation has been implicated as a potential mechanism underlying anxiety and mood disorders. Changes in hormonal secretion during the different phases of the estrous cycle may underlie changes in emotional reactivity to stressful events in female animals. Previous behavioral studies of sex differences in emotion processing in females have yielded conflicting results. This may be due to the range of different behavioral tests used and difficulties in selecting the best animal models to test for estrous cycle-linked differences in responsiveness. Furthermore, the commonly used behavioral tests were developed in male animals and it may not be appropriate to translate directly the protocols from males to females. In the present study we have attempted to address these problems by using different animal models of anxiety based on tests for unconditioned or conditioned fear. We compared the performance of male rats and female rats at four stages of the estrous cycle defined by differences in vaginal cytology. To test for unconditioned fear, we used two tests: a light switch- off test, in which rats escape to the other compartment of a shuttle-box to turn off an aversive light and recordings of 22 kHz ultrasound vocalizations (USVs) during acute restraint stress. For the conditioned fear paradigm, we used fear potentiated startle in an aversive context and conditioned freezing using an aversive context as the conditioned stimulus. In both tests of conditioned fear there were no gender or estrous cycle-linked differences in emotional reactivity. However, with respect to unconditioned fear, female rats in late diestrus showed greater emotional reactivity expressed as switch-off responses to a light environment and USVs in response to restraint compared to other phases of the cycle. These findings suggest that the hormonal profile during the late diestrous phase may predispose to up-regulated emotional reactivity in rats facing emotional challenges to unconditioned, but not conditioned fear- inducing stimuli.