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The Amount and Direction of Change of Background Noise as a Conditioned StimulusHilton, Anthony 05 1900 (has links)
This thesis is concerned with intensity characteristics of conditioned stimuli in acquisition of a conditioned emotional response (CER) in rats. A comparison was made of CSs which differed (between groups) with respect to amount and direction of change in white noise from a constant background stimulation level. The measure of conditioning was the degree to which the CS disrupted ongoing, food-motivated, bar-pressing activity. The major findings were (1) that rate of conditioning was a monotonic increasing function of amount of intensity change in either direction; and (2) an increase in noise intensity from background X to CS Y produced more rapid acquisition of the CER than did a decrease from background Y to CS X. (3) During pretests, a noise increase produced a small, but reliable, Increase in rate of bar-pressing, while a noise decrease produced a slight suppression. / Thesis / Master of Arts (MA)
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The Effects of the Intensity of the Unconditioned Stimulus on the Acquisition and Extinction of the Conditioned Emotional ResponseAnnau, Zoltan 05 1900 (has links)
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)
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AN INVESTIGATION OF THE PROCESS OF WORD RECOGNITIONLambert, Ronald Dick 09 1900 (has links)
Two experiments were conducted to examine parameters of the process of word recognition. In both experiments, subjects were required to guess the identity of words from which letters
were exposed.
In the first experiment, independent variables were frequency of occurrence in the language of stimulus words, number of letters selected from the words, and the position of the letters within the words. All three variables yielded significant effects.
Connotative meaning of the stimulus words and the number of letters exposed from the beginning of the words were varied in the second experiment. As in the first experiment, the effect due to number of letters was significant. Connotative meaning, however, did not contribute significantly to subjects’ recognition latencies. / Thesis / Master of Arts (MA)
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Binding of bacteria to poly (N-isopropylacrylamide) modified with vancomycin: Comparison of behavior of linear and highly branched polymersTeratanatorn, P., Hoskins, Richard, Swift, Thomas, Douglas, C.W.I., Shepherd, J., Rimmer, Stephen 21 July 2017 (has links)
Yes / The behavior of a linear copolymer of N-isopropyl acrylamide with pendant vancomycin functionality was compared to an analogous highly branched copolymer with vancomycin functionality at the chain ends. Highly branched poly(N-isopropylacrylamide) modified with vancomycin (HB-PNIPAM-van) was synthesized by functionalization of the HB-PNIPAM, prepared using reversible addition-fragmentation chain transfer polymerization. Linear PNIPAM with pendant vancomycin functionality (L-PNIPAM-van) was synthesized by functionalization of poly(N-isopropyl acrylamide-co-vinyl benzoic acid). HB-PNIPAM-van aggregated S. aureus effectively whereas the L-PNIPAM-van polymer did not. It was found that when the HB-PNIPAM-van was incubated with S. aureus the resultant phase transition provided an increase in the intensity of fluorescence of a solvatochromic dye, nile red, added to the system. In contrast, a significantly lower increase in fluorescence intensity was obtained when L-PNIPAM-van was incubated with S. aureus. These data showed that the degree of desolvation of HB-PNIPAM-van was much greater than the desolvation of the linear version. Using microCalorimetry it was shown that there were no significant differences in the affinities of the polymer ligands for D-Ala-D-Ala and therefore differences in the interactions with bacteria were associated with changes in the probability of access of the polymer bound ligands to the D-Ala-D-Ala dipeptide. The data support the hypothesis that generation of polymer systems that respond to cellular targets, for applications such as cell targeting, detection of pathogens etc., requires the use of branched polymers with ligands situated at the chain ends. / MRC
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L'efficacité du contrôle par le stimulus dans la thérapie cognitive-comportementale de l'insomnie chez les adultes : recension systématique et méta-analyse en réseauDemers Verreault, Mikael 26 March 2024 (has links)
Titre de l'écran-titre (visionné le 25 octobre 2023) / L'insomnie persistante est un trouble du sommeil fréquent qui touche environ 10 % à 15 % de la population adulte générale. La thérapie cognitive-comportementale de l'insomnie (TCC-I) est le traitement recommandé en première ligne pour ce trouble. Les écrits scientifiques suggèrent un manque de connaissances vis-à-vis certaines composantes de la TCC-I, dont le contrôle par le stimulus (SCT). Le présent mémoire s'intéresse à mieux comprendre le SCT afin d'en améliorer la portée thérapeutique. D'abord, une recension systématique a été réalisée afin de documenter les variantes dans les consignes du SCT ainsi que leur efficacité chez les adultes souffrant d'insomnie. Ensuite, trois méta-analyses en réseau ont été effectuées afin d'estimer et comparer l'efficacité du SCT à d'autres interventions psychologiques utilisées pour le traitement de l'insomnie. Une recherche documentaire a été effectuée dans les bases de données MEDLINE, PsycINFO, Embase, CINAHL, Psychology & Behavioral Sciences Collection, Web of Science et Cochrane Library sans restriction de langues entre la date de la première parution du SCT en 1972 et le 6 juin 2022. Vingt-trois études comprenant 1 603 participants ont été incluses. Les résultats indiquent que le SCT est une intervention individuelle efficace lorsque comparée à des conditions contrôles pour diminuer la latence d'endormissement et le temps total d'éveil pendant la nuit ainsi que pour augmenter le temps total de sommeil. Également, l'efficacité du SCT est comparable à plusieurs autres interventions psychologiques qui comprennent parfois des consignes contraires à celles proposées dans le SCT. Ces résultats suggèrent que certaines consignes du SCT (c.-à-d., réserver la chambre à coucher aux activités sexuelles et à dormir ainsi que sortir du lit après 10 à 15 minutes d'éveil) semblent être les moins optimales. De nouvelles études testant l'efficacité des différentes consignes du SCT sont nécessaires afin de comprendre davantage les mécanismes d'action du SCT et augmenter son efficacité. / Persistent insomnia is a common sleep disorder that affects approximately 10-15% of the general adult population. Cognitive-behavioral therapy for insomnia (CBT-I) is the recommended first-line treatment for this disorder. The scientific literature reveals a lack of knowledge regarding certain characteristics of CBT-I, including stimulus control (SCT). This doctoral dissertation focuses on better understanding SCT in order to improve its therapeutic scope. First, a systematic review was conducted to document the variations in the SCT instructions and their effectiveness in adults with insomnia. Next, three network meta-analyses were performed to estimate and compare the effectiveness of SCT to other psychological interventions used for the treatment of insomnia. A literature search was performed in MEDLINE (Ovid), PsycINFO (Ovid), Embase (Elsevier), CINAHL (EBSCO), Psychology & Behavioral Sciences Collection (EBSCO), Web of Science and Cochrane Library (Wiley) databases without language restriction between the date of the first publication of the SCT in 1972 and June 6, 2022. 23 studies with 1603 participants were included. The quality of the included studies was generally poor. The results indicate that SCT is an effective individual intervention when compared to control conditions in decreasing sleep onset latency and wake after sleep onset as well as increasing total sleep time. Also, the effectiveness of the SCT is comparable to several other psychological interventions that sometimes include instructions contrary to those proposed in the SCT. These results suggest that certain SCT instructions (i.e., reserve the bedroom for sexual activities and sleeping and getting out of bed after 10 to 15 minutes) seem to be the least optimal. Also, the results further support the hypothesis of cognitive or emotional activation regarding the mechanism of action of SCT. Further studies testing the effectiveness of different SCT instructions are needed to better understand the mechanism of action of SCT and to increase its effectiveness.
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A Stimulus Control Analysis of the Misinformation EffectTait, Kelly M. 08 1900 (has links)
This paper explores research on the misinformation effect and hypothesizes a new explanation for the occurrence misinformation effect. Current psychological theories states the misinformation effect occurs when memories are skewed by the presentation of new information after an initial event. This effect has been tested in a multitude of ways, including testing words lists, pictures, colors, and change blindness. Socially, the misinformation effect has been used to explain the inaccuracies of eyewitness testimony. The current judicial system relies on the fallible memory of people and has wrongfully imprisoned numerous innocents. The purpose of this research is to show the misinformation effect is not a problem with memory storage and retrieval, but rather a product of selective stimulus control.
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Conception de générateurs sinusoïdaux embarqués pour l'auto-test des circuits mixtes / Design of embedded sinusoidal signal generators for mixed signal Built-in Self-TestMalloug, Hani 28 September 2018 (has links)
Développer un générateur de signal analogique efficace est un élément clés pour les BIST des circuits analogiques et mixtes afin de produire le stimulus de test approprié, et remplacer les générateurs de signaux externes couteux dans les protocoles de standard de test fonctionnel analogique et mixte. Dans cette optique, nous présentons dans cette thèse des stratégies différentes de génération de signal sinusoïdal, basées sur les techniques d’annulation d’harmonique, pour le design d’un synthétiseur embarqué de signal sinusoïdal à haute fréquence. Les générateurs proposés utilisent des circuits numériques pour produire un ensemble de signaux carrés déphasés. Ces signaux carrés sont pondérés et combinés en appliquant différentes stratégies d’annulation d’harmonique dans un convertisseur numérique-analogique simplifié. Le générateur sélectionné permet d’annuler toutes les harmoniques en dessous de la 11ème. De plus, une simple stratégie de calibration a été conçue pour compenser l’effet de mismatch et de la variation de process de fabrication sur l’efficacité de la technique d’annulation d’harmonique. La simplicité du circuit rend cette approche adaptable pour le BIST des circuits intégrés analogique et mixte. Les modèles comportementaux, les simulations électriques d’un design en 28nm FDSOI et les résultats expérimentaux sont fournis pour valider la fonctionnalité du générateur proposé. Les résultats obtenus montrent des performances du circuit calibré autour de 52dB de SFDR pour un signal généré à 166MHz. / One of the main key points to enable mixed-signal BIST solutions is the development of efficient on-chip analog signal generators that can provide appropriate test stimuli and replace costly external signal generators in standard analog and mixed-signal functional test protocols. In this line, we present in this thesis different sinewave generation strategies based on harmonic cancellation techniques to design a high-frequency on-chip sinusoidal synthetize. The proposed generators employ digital hardware to provide a set of phase-shifted digital square-wave signals. These square-wave signals are scaled and combined using different harmonic cancellation strategies in a simplified current-steering DAC. The selected generator allows the cancellation of all harmonic components up to the eleventh. Additionally, a simple calibration strategy has been devised to compensate the impact of process variations and mismatch on the effectiveness of the harmonic cancellation. The simplicity of the circuitry makes this approach suitable for mixed-signal BIST applications. Electrical simulations of a 28nm FDSOI design and experimental results are provided to validate the functionality of the proposed signal generator. Obtained results show a calibrated performance around 52dB of SFDR for a generated sinusoidal signal at 166 MHz.
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The behavorial effects of mere exposure in response to affectively neutral and negatively valenced stimuliYoung, Steven G. January 2007 (has links)
Thesis (M.A.)--Miami University, Dept. of Psychology, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 21-24).
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Contrasting the extended comparator hypothesis and acquisition-focused models of learning differential predictions of retrospective revaluation /McConnell, Bridget L. January 2008 (has links)
Thesis (M.S.)--State University of New York at Binghamton, Department of Psychology, 2008. / Includes bibliographical references.
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Efeitos de estímulos emocionais sobre a ocorrência de falsas memórias : investigação por meio do paradigma da equivalência de estímulos / Effects of emotional stimuli on the occurrence of false memories : investigation through the paradigm of the equivalence of stimuliPedrosa, Sabrina Campos Dias 29 March 2017 (has links)
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Previous issue date: 2017-03-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / False memories can be defined as recollections that do not correspond to the facts experienced by subjects. Cognitive research have pointed out that the referred phenomenon is, to some extent, determined by semantic relations among stimuli. Based on these studies, behavior analysts have proposed experimental analogous of false memories using the stimulus equivalence paradigm to establish symbolic relations. The current master’s thesis was composed by one preliminary study and two main studies. The preliminary study aimed to assess the valence and arousal of pictures depicting facial expressions, and to select the meaningful stimuli that were employed on the class formation procedures of Studies 1 and 2. Study 1 aimed to analyze possible effects of emotional stimuli with different valences (positive, neutral and negative) on the occurrence of false memories. For this purpose, a systematic replication of Aggio’s (2014) Study 3, using lists of symbolically related stimuli through the stimulus equivalence paradigm was carried out. The main experimental manipulations of Study 1, in the present thesis, were the control of valence and arousal magnitudes attributed to the emotional stimuli; the use of emotional stimuli in the class formation procedure, which contained the unrelated distracting stimuli; and the randomization of list order presentation. Study 1 was structured in four phases, which encompassed 1) the establishment of six equivalence classes; 2) a false memories test with a memorization task and a recognition test, held one week after the beginning of Phase 1; 3) class merger and maintenance test, and 4) stimuli assessment through a semantic differential. Results showed that the false memories effect, under symbolic control, occurred only in relation to the positive stimuli list. It was hypothesized that the stability of the equivalence classes was an intervening variable. In order to verify the aforementioned hypothesis and search for new evidences regarding the effects of emotional valence on the establishment of false memories, a second study was proposed. The Study 2 had the same procedure as Study 1, with the exception of two changes: the reduction of the time interval employed between the first and the second phase, and the insertion of baseline review blocks of the six equivalence classes before the false memories test. These changes were adopted in order to increase the probability that the equivalence relations were stable and strengthened at the moment of the false memories test. Results showed the occurrence of the false memories effect in positive and neutral lists. These results suggest that stimuli with negative emotional valence can reduce the probability of false memories occurrence. / Falsas memórias podem ser definidas como lembranças não fidedignas aos fatos vivenciados pelos sujeitos. Pesquisas de base cognitivista têm apontado que o referido fenômeno é, em alguma medida, determinado por relações semânticas entre estímulos. A partir dessas evidências, analistas do comportamento propuseram análogos experimentais de falsas memórias com o emprego do paradigma da equivalência de estímulos como recurso para o estabelecimento de relações simbólicas. A presente dissertação foi composta por um estudo preliminar e por dois estudos principais. O estudo preliminar objetivou avaliar as propriedades de valência e alerta de imagens de expressões faciais, além de selecionar os estímulos significativos que seriam empregados na formação das classes de equivalência estabelecidas nos Estudos 1 e 2. O Estudo1 visou analisar os possíveis efeitos de estímulos emocionais com diferentes valências (positiva, neutra e negativa) sobre a ocorrência de falsas memórias. Para tanto, foi proposta uma replicação sistemática do Estudo 3 de Aggio (2014), o qual fez uso de listas de estímulos simbolicamente relacionados por meio do paradigma da equivalência de estímulos. As principais manipulações experimentais propostas, no Estudo 1, da presente dissertação, foram o controle das magnitudes das propriedades de valência e alerta atribuídas aos estímulos emocionais; a utilização de estímulos emocionais na formação das classes que continham os distratores não relacionados e o balanceamento das ordens de apresentação das listas. O Estudo 1 foi estruturado em quatro fases que envolveram: 1) estabelecimento de seis classes de equivalência; 2) teste de falsas memórias, compreendendo uma tarefa de memorização e um teste de reconhecimento, realizados uma semana após o início da Fase 1; 3) teste de fusão e de manutenção de classes e 4) avaliação de estímulos por meio de instrumento de diferencial semântico. Os resultados demonstraram que o efeito de falsas memórias, sob controle simbólico, ocorreu apenas na lista de estímulos de valência positiva. A estabilidade das classes de equivalência foi apontada como uma possível variável interveniente na determinação dos referidos resultados. A fim de verificar a hipótese supracitada e buscar novas evidências em relação aos efeitos da valência emocional, sobre o fenômeno das falsas memórias, foi proposto um segundo estudo. O Estudo 2 teve um procedimento idêntico ao adotado no Estudo 1, com exceção de duas modificações: a redução do intervalo de tempo empregado entre a primeira e a segunda fase e a inserção de blocos de revisão de relações de linha de base das seis classes de equivalência, antes da realização das tarefas de teste de falsas memórias. As alterações citadas foram adotadas a fim de aumentar a probabilidade de que as relações de equivalência estivessem estáveis e fortalecidas no momento de realização das tarefas de teste de falsas memórias. Os resultados indicaram a ocorrência do efeito de falsas memórias nas listas de valência positiva e neutra. Os referidos resultados sugerem que estímulos com valência emocional negativa podem reduzir a probabilidade de ocorrência de falsas memórias.
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