The present study examined whether cardiovascular habituation to stress is affected by a change in the physical context in which a stressor is encountered. Twenty-five undergraduate students at the University of Central Florida, Palm Bay Campus, were exposed to 4 trials of a stressor consisting of mental arithmetic while under evaluative observation. It was hypothesized that if participants experienced a change in the physical context in which stress was experienced on the final trial, they would demonstrate impaired habituation to stress as indicated by measures of heart rate and blood pressure. Physical context was manipulated by either asking participants to move to another room upon the final exposure to the stressor or to remain in the same room in which they were initially exposed to the stressor for the final exposure. Participants were randomly assigned to one of 2 conditions, the Stable Room Condition (N = 10) or Novel Room condition (N = 15 ). Participants in the Stable Room Condition remained in the same physical context, or same room, throughout all trials and displayed habituation of systolic .blood pressure, diastolic blood pressure, and heart rate. Participants in the Novel Room condition were exposed to the same stressors, but were moved to a different physical context, or new room upon the final trial. The results demonstrated that participants in the novel room condition displayed significantly impaired habituation on measures on systolic blood pressure (p < .001) and diastolic blood pressure (p < .001). However, no significant difference in heart rate was observed between groups. These results indicate that a simple change in the physical context in which stress exposure occurs impairs cardiovascular habituation to stress. Implications and directions for future research are discussed.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This thesis reports on research examining the habituation of emotional variables to filmed violence. The following subjective emotional variables were assessed: positive feelings, anxiety, disgust, entertainment and anger. In addition, an objective measure of emotional response was recorded physiologically, using the startle eyeblink response. The mediating influence of personality, individual differences and contextual features on an individuals’ perception of and reaction to filmed violence were also explored. Study one was exploratory in nature served to identify and select the film stimuli to be employed in the subsequent studies. The primary aim of the study was to allow for the identification of violent stimuli considered to be most socially and culturally relevant. The present research builds on existing scientific literature which has began to appreciate that differences in the context of a portrayal holds important implications for its impact on viewers. Thus, a secondary and more specific desire of study one was to obtain an evaluation of the contextual features of the violent film segments. A sample of 30 participants viewed and rated the film stimuli on the variables of realism, fantasy and violence. From this exploratory study four violent film stimuli were subsequently employed. Study 2 used the eyeblink startle response proposed by Vrana, Spence and Lang (1988) to explore the habituation of emotional variables to a realistic depiction of filmed violence. Emotional response was assessed both objectively, using the eyeblink startle response and subjectively through individuals self-reports. In addition the study investigated the significance of individual differences as mediators of emotional response. Questionnaire and physiological data were obtained from 30 participants. Overall, repeated exposure to filmed violence resulted in a decline in both objective and subjective emotional response. Differences were identified in the manner in which men and women responded to the film. Women reacted initially and over time with more intense physiological and psychological reactions to the violent film than males. Specifically, men displayed more curiosity and reported greater entertainment and positive feelings in response to the film, whilst women found the violence more disgusting and reported higher levels of anger and anxiety. It was found that the eyeblink startle magnitude paralleled the subjective emotional processing of the violent film, thus providing further confirmatory evidence of its validity in the investigation of emotional reactions to a stimulus. Personality factors were found to mediate emotional response to filmed violence, with neuroticism most powerfully implicated. High levels of neuroticism were found to be associated with greater anger and anxiety and less positive feelings whilst viewing violent film. A high score on extraversion was correlated with higher levels of anger and lower levels of curiosity and entertainment. Whilst the aims of study 3 were identical to that of study 2, a variation in the contextual feature of the violent film stimuli under investigation was the distinguishing and pertinent feature. Study 2 provided data on the habituation of emotional response to a realistic depiction of filmed violence. Study 3 was concerned with emotional response over repeated exposure to a fantasized violent depiction. Therefore, allowing for a comparison regarding the effects of context on emotional response. The results of study 3, with respect to habituation of emotional response, personality and individual differences, were similar to that obtained in study 2. A comparison of the two studies, however, revealed that individuals responded significantly different to the contextual features of the violent portrayal. Compared to the fantasised portrayal the realistic film stimulus was reported to be more digusting, anxiety provoking and less entertaining. In addition, and not surprisingly respondents reported that the realistic portrayal resulted in the production of more anger and less positive feelings.

This thesis explores Aristotle's theories of habituation and voluntariness and their impact on his ability to attribute moral responsibility to agents. Ultimately, I conclude that Aristotle should drop his assertions that we are morally responsible for our states of character in order to accommodate a compatibilist view that will still allow him to attribute moral responsibility for action to agents.

Aristotle famously claims that we become virtuous by performing virtuous actions. He also recognizes the potential puzzle this claim gives rise to: How can we perform virtuous actions unless we are already virtuous? After all, virtuous actions require virtuous motives – they are performed “for the sake of the noble” – and virtuous motives characteristically belong to virtuous people. Many modern commentators presume that Aristotle’s solution rests upon characterizing the actions of learners as actions that are the right things to do in the circumstances but are not done with virtuous motivation. But this leaves Aristotle with the problem of bridging what I call “the moral upbringing gap” – i.e. the gap between the motivationally-neutral actions of learners and the dispositions to act reliably from a virtuous motive that such actions are supposed to produce. This gap emerges because the weaker the link between the way in which the actions of learners are performed and the way in which virtuous actions are done by virtuous agents, the more difficult it will be to understand how the repeated performance of the learners’ actions produce genuinely virtuous dispositions. The main aim of this thesis is to show that (and how) shame plays a crucial role in the process of moral development as the moral emotion that provides continuity between the actions of the learners of virtue and the corresponding dispositions that those actions eventually yield. My view is that Aristotle understands shame not as mere fear of external disapproval, nor as mere tendency to find pleasure in the noble, but as an emotion responsive to praise and blame and consequently to considerations about the nobility and shamefulness of one’s own actions and one’s character. Understood this way, shame provides learners with the sort of motivation that allows them to perform genuinely virtuous actions before they have acquired practical wisdom and the stable dispositions characteristic of virtuous agents. Shame thus bridges the “moral upbringing gap” by providing the kind of motivation that, when entrenched by understanding, constitutes moral virtue.

Aristotle famously claims that we become virtuous by performing virtuous actions. He also recognizes the potential puzzle this claim gives rise to: How can we perform virtuous actions unless we are already virtuous? After all, virtuous actions require virtuous motives – they are performed “for the sake of the noble” – and virtuous motives characteristically belong to virtuous people. Many modern commentators presume that Aristotle’s solution rests upon characterizing the actions of learners as actions that are the right things to do in the circumstances but are not done with virtuous motivation. But this leaves Aristotle with the problem of bridging what I call “the moral upbringing gap” – i.e. the gap between the motivationally-neutral actions of learners and the dispositions to act reliably from a virtuous motive that such actions are supposed to produce. This gap emerges because the weaker the link between the way in which the actions of learners are performed and the way in which virtuous actions are done by virtuous agents, the more difficult it will be to understand how the repeated performance of the learners’ actions produce genuinely virtuous dispositions. The main aim of this thesis is to show that (and how) shame plays a crucial role in the process of moral development as the moral emotion that provides continuity between the actions of the learners of virtue and the corresponding dispositions that those actions eventually yield. My view is that Aristotle understands shame not as mere fear of external disapproval, nor as mere tendency to find pleasure in the noble, but as an emotion responsive to praise and blame and consequently to considerations about the nobility and shamefulness of one’s own actions and one’s character. Understood this way, shame provides learners with the sort of motivation that allows them to perform genuinely virtuous actions before they have acquired practical wisdom and the stable dispositions characteristic of virtuous agents. Shame thus bridges the “moral upbringing gap” by providing the kind of motivation that, when entrenched by understanding, constitutes moral virtue.

The ability to detect and react to a predator odour is crucial for prey species. In the present study 10 mice (Mus musculus) were used to test the behavioural response of mice towards two predator odours (3-methyl-1-butanethiol and 3-mercapto-3-methyl-butan-1-ol) and one fruity odour (n-pentyl acetate). All three odours were tested against a near odourless blank stimulus (diethyl phthalate). The animals were individually placed in a test chamber of two equally sized compartments divided by a vertical Plexiglas wall with a semicircular opening. Their proximity to the odours, placed beneath the floor in petri dishes in each compartment, was measured continuously with stop watches. The mice spent less time in proximity to 3-methyl-1-butanethiol and n-pentyl acetate compared to diethyl phthalate (P&lt;0,05). The mice did not prefer any specific compartment in the test with 3-mercapto-3-methyl-butan-1-ol compared to diethyl phthalate (P&gt;0,05). The avoidance of 3-methyl-1-butanethiol and n-pentyl acetate can be explained either by neophobia, or in the case of 3-methyl-1-butanethiol that it contains sulphur. The lack of behavioural response towards 3-mercapto-3-methyl-butan-1-ol may be due to its loss of intensity over time. From this study it is not certain if mice have an innate fear of predator odours.

No description available.

A significant goal in studies on learning and memory is to relate cellular plasticity to the modification of behaviour. The phenomenon of dual-process learning affords an ideal opportunity to explore the complexities inherent in establishing this relationship. Dual-process learning occurs when depression (habituation) and facilitation (sensitization) are expressed simultaneously within a neural network and compete to determine the behavioural outcome. A large body of literature is reviewed to define characteristics which are common across the neural networks that exhibit dual-process learning: depression occurs at loci early in the reflex pathway, upstream of the modulatory system necessary for the induction of facilitation. Consequently, depression not only competes directly with facilitation for the determination, of behavioural change (by serial and/or parallel expression), but depression also precludes the ongoing development and maintenance of sensitization (by serial induction). A mathematical model is presented to formally describe the nature of this competition and how this competition leads to the kinetics of dual-process learning. The tentacle withdrawal reflex of the snag Helix aspersa exhibits dual-process learning and was further investigated in this study. The neural circuit mediating tentacle withdrawal is described along with the nature and the location of plasticity which occurs within that circuit. In turn, plasticity at the cellular level is related, via the network level, to plasticity at the behavioural level. The data demonstrate the importance of localizing the sites of plasticity within a neural network in order to explain (1) how plasticity at a particular locus influences plasticity occurring elsewhere in the network and (2) how plasticity at different loci affect different aspects of behaviour.

The goal habituation model of vigilance proposed by Ariga and Lleras (2011) posits that it is possible to attenuate the vigilance decrement (the decline in performance that occurs with time-on-task) through dis-habituation of a vigilance task’s goal. The goal in a vigilance task is to detect critical signals. Hence, a switch away from this goal should dishabituate the task goal. When a person resumes the vigilance task, the person’s performance should improve. Follow up studies to the Ariga and Lleras study have not found supporting evidence (Helton & Russell, 2011; 2012). The methods in these follow up studies differed from those of Ariga and Lleras in a number of ways. The present study attempts to replicate the original Ariga and Lleras (2011) work using methods that more closely follow the original study. The present research sought to uncover confounds in the original article through replicating the original task and manipulating variables in line with hypotheses made by attentional resource theory. Overall, the results of this research present a challenge to the goal habituation model. Rest breaks, not goal switching; lessened the magnitude of the decline in sensitivity with time on task, while task switching resulted in a temporary re-correction of increasingly conservative responding that occurred with greater time on task. We also found support for the context dependent relationship of task-unrelated thought, (TUT) and task demand. Given that the vigil was determined to impose relatively low workload, pre-task TUT was associated with average performance rather than post-task TUT. Finally, we discuss the dangers of over compliance with signal detection theory (SDT) measures. We explain that SDT sensitivity and bias measures are not independent given responding floor and ceiling effects during low demanding tasks such as the present. It is argued that this may have distorted the original conclusion arrived at by Ariga and Lleras (2011).