When making decisions, individuals evaluate several possible outcomes of their choice; however, some display heightened reward sensitivity, despite the potential for future negative consequences, which can lead one to make risky choices. Rewards are processed in the mesolimbic dopamine reward system, and this system is in part modulated by genetic polymorphisms that are associated with dopamine transmission. The current study tested if genetic polymorphisms that are associated with enhanced dopamine neurotransmission will be more neurally reward sensitive, score higher on self-reported impulsivity, and make riskier choices. In a sample of 85 participants, five genetic polymorphisms were genotyped and used to create a genetic risk score that represented dopamine transmission efficiency. Two groups (high and low efficiency) were created via median split and then compared on neural reward sensitivity (assessed by event-related potentials, specifically, the medial-frontal negativity [MFN] and the error-related negativity), impulsivity (assessed via self-report), and risky choice (measured using the Balloon Analogue Risk Task and self-report measures). Results indicated that individuals with higher levels of dopamine displayed a less negative MFN and more drinking behaviors than those with lower levels of dopamine. These results suggest that individuals with higher levels of dopamine are less sensitive to punishments, which could lead them to make riskier choices.

Over 20 years of research on terror management theory has demonstrated that reminders of death (mortality salience; MS) heighten individuals' investment in prioritized bases of value and meaning. Research in this vein has shown that MS intensifies people's efforts to demonstrate personal value on tasks relevant to their self-esteem ("self-esteem striving"). Though much work illustrates that such responses function to mitigate death-related concerns, to date no work has directly assessed the particular regulatory mechanisms that implement MS-induced self-esteem striving. The present study aimed to do so by measuring neural indices of performance monitoring. During a tasked framed as diagnostic of self-esteem relevant attributes, participants were randomly assigned to receive subliminal primes of the word death or of control terms. Response-locked brain signals were recorded to assess reactivity to correct and incorrect responses during the task. Results showed that death-primed (vs. control) participants exhibited greater neural reactivity following error commission as indexed by larger amplitude of the Error Related Negativity (ERN). Death-primed (vs. control) participants also exhibited intensified behavioral efforts to improve their performance following error commission (i.e., post-error slowing, post-error accuracy), effects that were likely mediated by the activity of neural mechanisms that generate the ERN. Furthermore, among death-primed participants, behavioral improvements on the self-esteem relevant task correlated with attenuations in death thought accessibility. Receiving death primes did not influence neural reactivity to correct responses (Correct Related Negativity; CRN) nor did it heighten a neural index of explicit error awareness (Error Positivity; Pe). Together these findings suggest that MS-induced self-esteem striving is implemented via automatic monitoring and avoidance of errors. The role of avoidance motivation in self-esteem striving is thus discussed.

Examined was whether the mismatch negativity (MMN) varied predictably in response to changes in the direction of frequency-modulated tone glides and equivalent second formant transitions in vowels (e.g., /ɪ/ as in “bit” and /e/ as in “bate”). A novel stimulus presentation paradigm was designed to distinguish the MMN from the N1 component. 10 normal-hearing adults with no neurological diseases were recruited and presented stimuli via insert earphones while they watched a silent, subtitled movie. Event-related potentials (ERPs) were recorded from 128 scalp electrodes. The MMN was successfully distinguished from the N1, marking participants’ ability to discriminate vowel stimuli only. A significant early P2 component, which decreased in size with successive stimulus presentations, was also elicited for vowels only and is believed to reflect formant encoding. Discrepancies between vowel and tone results are discussed along with clinical implications and contributions to the fields of ERP and vowel research.

The present thesis employed event-related potentials, the minute responses of the brain, to examine the differences in processing of increases and decreases in auditory intensity. The manner in which intensity was manipulated (i.e., whether it represented physical or psychological change) varied across the studies of the thesis. Study 1 investigated the processing of physical intensity change during wakefulness and natural sleep. An oddball paradigm (80 dB standard, 90 dB increment, 60 dB decrement) was presented to subjects during the waking state and during sleep. The increment elicited a larger deviant-related negativity and P3a than the decrement in the waking state. During sleep, only the increment deviant continued to elicit ERPs related to the detection of change. The waking and sleeping findings support the notion that increases in intensity are more salient to an observer. Studies 2 and 3 of this thesis determined the degree to which this differential salience could be attributed to the fact that intensity increments result in increased activation of the change and transient detection systems while intensity decrements result in greater activation of only the change detection system. In order to address this question, an alternating intensity pattern was employed (HLHLHLHL) with deviants created by the repetition of a tone in the sequence (HLHLHHHL) that violated the expectancy for a higher (psychological decrements) or lower intensity tone (psychological increments). Because deviant stimuli were physically identical to preceding standards, this manipulation should not have led to increased output of the transient detection system (N1 enhancement), permitting isolation of the output of the change detection system (Mismatch Negativity, MMN). The findings of these studies indicated that psychological increments resulted in shorter latency and larger amplitude MMNs than psychological decrements and that these differences could not be explained by the physical differences between deviant stimuli or temporal integration. This thesis provides convincing evidence that stimuli representing increments in intensity result in faster and more robust change detection. Further, the increased salience of increment stimuli cannot be solely explained by the contribution of transient detector activation, as it persists even when deviance-related processing is isolated to the change detection system.

Current research in stuttering suggests that individuals who stutter (IWS) may have a hyperactive error-monitoring system, leading to the exacerbation and anticipation of verbal dysfluencies. Using a neurophysiological marker of error processing known as the feedback error-related negativity, the current thesis involved three studies. First, a pilot study was conducted to ensure that word feedback cues were usable in the current paradigm. Second, a classic virtual T-maze task was used to assess the generic error processing mechanism of IWS. Third, an adaptation of the T-maze was used to assess the integrity of the reinforcement learning system of IWS and their ability to associate reward and error information of personalized problem words with predictive cues. Results suggest preliminary evidence for functional generic error processing in IWS and disrupted error processing when conditioned predictive cues are needed to predict fluent versus dysfluent outcomes. / Graduate

Relying mainly on R. B. Pippin’s and D. Moggach’s interpretative works on Kant and Hegel, the thesis tackles the problem of the reception of Kant by Hegel. It does so by looking into the impact of Kant’s first critique on the Preface, the Introduction and the first part of the section Self-consciousness of the Phenomenology of Spirit. Three Kantian conditions for there to be freedom are identified and shown to be reinterpreted by Hegel in a continuist perspective. These three conditions are spontaneity, reflectivity and negativity which propels and retains the free Kantian subject in the Hegelian becoming of reality.

Mental disorders present difficulties in the research of their mechanisms, considering the high levels of comorbidity and the lack of specific neuroscience data to evaluate them. Estipulating deficit circuits in the disorders and the best treatment is a complex task, given the limited comprehension of the factors that correlate to the disorders. The utilization of biomarkers has proved an efficient and reliable alternative to provide precise diagnosis. Among the biomarkers, the Error-Related Negativity component, an event-related cortical potential, has presented high indexes of stability and validity in correlating to anxiety, obsessive, and mood-related mental disorders. The present dissertation evaluated irritability traits in a community sample, using a Flanker task, that has consistently elicited Error-Related Negativity according to the literature. Our results corroborate literature and found a frontocentral negativity, that peaked around 100ms after the commission of an error in the Flanker Task. However, our manipulation of negative feedback did not support literature, and ERN amplitudes were less enhanced post negative feedback. The relationship between irritability and ERN remains unclear. Future studies should, therefore, address these questionings.

Neural correlates of consciousness (NCCs) represent the physiological processes related to consciousness and awareness. Consciousness is theorized as a recurrent process of integration between separate but specialized brain areas. Previous research has used electroencephalography (EEG) to locate NCCs of sensory awareness in vision through event-related potentials (ERPs). Two ERP components thought to represent visual awareness are the visual awareness negativity (VAN) and late positivity (LP). VAN and LP have been extensively studied, yet little research has been conducted in other sensory modalities. In this study, the presence of an auditory awareness negativity (AAN) and associated LP is investigated in 23 subjects using EEG. To avoid false positives in data analysis, two research hypotheses were preregistered. The results indicate that auditory LP does occur, but that AAN does not, in hypothesized intervals. However, the data suggest that AAN may occur at a later interval. Possible attributes of the later interval are discussed. In sum, the data provide results consistent with recurrent theories of sensory awareness.

Auditiv mismatch negativity (MMN) är en neurologisk hjärnrespons som visar hur känslig hjärnan är för auditiva förändringar. Perceptuell load teorin argumenterar att krävande visuella sökuppgifter eliminerar auditiva distraktorer från att bearbetas i arbetsminnet. Syftet är att observera event-related potential (ERP) händelser för att se om avvikande ljud exkluderas under hög visuell belastning. Ett korsmodalt uppmärksamhetstest utfördes där deltagarna (N = 26) fick utföra en visuell sökuppgift med två svårighetsgrader samtidigt som de skulle ignorera tonfrekvenser som spelades upp i bakgrunden. Resultatet visade auditiv MMN-respons under både låg och hög visuell belastning. Det fanns ingen tydlig skillnad på MMN mellan låg och hög belastning. Hörselcortex registrerade en avvikande ton i oddball och att samma ton fanns i kontroll-upplägget. Argument för att distraktorer bearbetas under kontrollerad uppmärksamhet. Ytterligare studier med större stickprov och olika ljudfrekvenser, naturliga och icke naturliga, krävs för att se hur ljuden påverkar bearbetningsprocessen.

[pt] Esta dissertação tem como objetivo a análise e articulação dos conceitos de trauma, repetição e pulsão de morte em Freud, embora algumas contribuições de psicanalistas pós-freudianos também sejam consideradas. A riqueza dos conceitos em questão se apresenta pelo seguinte paradoxo: ao mesmo tempo em que testemunham um limite do aparelho psíquico, lançam para o trabalho. O que motiva essa pesquisa, portanto, é justamente a indagação sobre as vicissitudes destes limites - limite do psiquismo e da representação, com o intuito de problematizá-los. Pois é preciso pensar sempre em uma dupla potencialidade do que se apresenta como limite: por um lado potência de abertura e por outro, agente de fechamento. Não queremos com isso diminuir a importância da representação no trabalho analítico como objetivo essencial, mas apontar para a importância da valorização e discriminação de modos de trabalho do psiquismo que não o trabalho representacional, buscando enfatizar a importância da negatividade para a o enriquecimento e complexificação do psiquismo. / [en] The purpose of this thesis is to analyse and articulate the concepts of trauma, repetition and death drive in Freud, although some contributions of post-freudian psychoanalysts will also be considered. The richness of these concepts can be sustained by the following paradox: they witness a limit of the psychic apparatus, at the same time that lances it for work. What motivates this research, therefore, is precisely the question about the vicissitudes of these limits - limits of the psyche and representation, in order to discuss them. One must always think about a dual capability that presents itself as a limit: one for the power of opening, and the other as a closing agent. This is not to diminish the importance of the representation in an analytical work as an essential goal, but to point out the importance of the valuation and discrimination of other working modes of the psyche rather than a representational work, in order to emphasize the importance of negativity for the enrichment and complexity of the psyche.