898 resultados para Context effects (Psychology)
Resumo:
Self-presentation is the process by which individuals attempt to monitor and control how others perceive and evaluate them (Leary, 1992; Leary & Kowalski, 1990). Self-presentational concerns have been shown to influence a number of exercise-related behaviours, cognitions, and affective responses to exercise (e.g., social anxiety). Social anxiety occurs when an individual wants to create a specific impression on others, but is unsure (s)he will be successful (Leary & Kowalski, 1995). Social physique anxiety (SPA) is a specific form of social anxiety related the evaluation of one's body (Hart, Leary, & Rejeski, 1989). Both social anxiety and SPA may act as deterrents to exercise (Lantz, Hardy, & Ainsworth, 1997; Leary, 1992), so it is important to examine factors that may influence social anxiety and SPA; one such factor is self-presentational efficacy (SPE). SPE is one's confidence in successfully making desired impressions on others (Leary & Atherton, 1986) and has been associated with social anxiety and SPA (Leary & Kowalski, 1995; Gammage, Martin Ginis, & Hall, 2004). Several aspects of the exercise environment, such as the presence of mirrors, clothing, and the exercise leader or other participant characteristics, may be manipulated to influence self-presentational concerns (e.g., Gammage, Martin Ginis et aI., 2004; Martin & Fox, 2001; Martin Ginis, Prapavessis, & Haase, 2005). Given that the exercise leader has been recognized as one of the most important influences in the group exercise context (Franklin, 1988), it is important to further examine how the leader may impact self-presentational concerns. The present study examined the impact of the exercise leader's gender and physique salience (i.e., the extent to which the body was emphasized) on SPE, state social anxiety (SSA), and state social physique anxiety (SPA-S) of women in a live exercise class. Eighty-seven college-aged female non- or infrequent exercisers (i.e., exercised 2 or fewer times per week) participated in a group exercise class led by one of four leaders: a female whose physique was salient; a female whose physique was non-salient; a male whose physique was salient; or a male whose physique was non-salient. Participants completed measures of SPE, SSA, and SPA-S prior to and following completion of a 30- minute group exercise class. In addition, a measure of social comparison to the exercise leader and other participants with respect to attractiveness, skill, and fitness was completed by participants following the exercise class. A MANOV A was conducted to examine differences between groups on postexercise variables. Results indicated that there were no significant differences between groups on measures ofSPE, SSA, or SPA-S (allp's > .05). However, when all participants were collapsed into one group, a MANOV A showed a significant time effect (F(3, 81) = 19.45,p < .05, 1')2= .419). Follow-up ANOVAs indicated that post-exercise SPE increased significantly, while SSA and SPA-S decreased significantly (SPE: F(I, 83) = 30.87,p < .001,1')2 = .27; SSA: F(I,83) = 11.09,p < .001, 1')2 = .12; SPA-S: F (1,83) = 42.79,p < .001, 1')2 = .34). Further, results of a MANOVA revealed that participants who believed they were less fit than other group members (i.e., made negative social comparisons) reported significantly more post-exercise SSA and SP A-S than those who believed they were more fit than the other participants (i.e., made positive comparisons; SSA: F(2, 84) = 3.46, p < .05, 1')2 = .08; SPA-S: F(2, 84) = 5.69, p < .05, 1')2 = .12). These results may indicate that successfully completing an exercise class may serve as a source of SPE and lead to reduced social anxiety and SPA-S in this population. Alternatively, characteristics of the exercise leader may be less important than characteristics of the other participants. These results also suggest that the types of social comparisons made may influence self-presentational concerns in this sample. Future research should examine how the type of social comparison (i.e., negative or positive) made to the other group members may either generate or reduce anxiety. Also, factors that contribute to the types of social comparisons made with other exercisers should be examined. Implications for practice and research are discussed.
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Age-related differences in information processing have often been explained through deficits in older adults' ability to ignore irrelevant stimuli and suppress inappropriate responses through inhibitory control processes. Functional imaging work on young adults by Nelson and colleagues (2003) has indicated that inferior frontal and anterior cingulate cortex playa key role in resolving interference effects during a delay-to-match memory task. Specifically, inferior frontal cortex appeared to be recruited under conditions of context interference while the anterior cingulate was associated with interference resolution at the stage of response selection. Related work has shown that specific neural activities related to interference resolution are not preserved in older adults, supporting the notion of age-related declines in inhibitory control (Jonides et aI., 2000, West et aI., 2004b). In this study the time course and nature of these inhibition-related processes were investigated in young and old adults using high-density ERPs collected during a modified Sternberg task. Participants were presented with four target letters followed by a probe that either did or did not match one of the target letters held in working memory. Inhibitory processes were evoked by manipulating the nature of cognitive conflict in a particular trial. Conflict in working memory was elicited through the presentation of a probe letter in immediately previous target sets. Response-based conflict was produced by presenting a negative probe that had just been viewed as a positive probe on the previous trial. Younger adults displayed a larger orienting response (P3a and P3b) to positive probes relative to a non-target baseline. Older adults produced the orienting P3a and 3 P3b waveforms but their responses did not differentiate between target and non-target stimuli. This age-related change in response to targetness is discussed in terms of "early selection/late correction" models of cognitive ageing. Younger adults also showed a sensitivity in their N450 response to different levels of interference. Source analysis of the N450 responses to the conflict trials of younger adults indicated an initial dipole in inferior frontal cortex and a subsequent dipole in anterior cingulate cortex, suggesting that inferior prefrontal regions may recruit the anterior cingulate to exert cognitive control functions. Individual older adults did show some evidence of an N450 response to conflict; however, this response was attenuated by a co-occurring positive deflection in the N450 time window. It is suggested that this positivity may reflect a form of compensatory activity in older adults to adapt to their decline in inhibitory control.
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The present research was designed to examine whether sex and/or emotional valence pl aya role in the cognitive consequences (e.g., memory) of expressive suppression. Seventy-two (36 male and 36 female) undergraduates were randomly assigned to either a control or expressive suppression condition, and were asked to watch silent film clips intended to elicit amusement and disgust. While watching each film, participants listened to sixteen nonemotional words. After each film, participants were asked to answer questions about wha t they had seen in the film (visual memory), to recall as many words as they could (auditory recall memory), and to select from a list any words that they had heard during the previous film clip (auditory recognition memory). With regard to the effects of expressive suppression on visual memory, results indicated a 3-way interaction between condition, sex and film emotion: Men performed more poorly than women on the visual memory test after watching both the amusing and disgusting films in the control condition, and when watching the amusing film in the expressive suppression condition. However, men in the expressive suppression condition performed better than women after watching the disgusting film. In terms of the effects of expressive suppression on auditory memory (recognition and recall), a condition x film emotion interaction indicated that there was no difference in auditory memory for the expressive suppression and control conditions when watching the amusing film, but that the expressive suppression group showed poorer auditory memory than the control group for words presented during the disgusting film. Moreover, a ma in effect of sex on auditory memory suggested that men recalled and recognized more words than women across conditions. Taken together, these findings suggest that both sex and the emotional valence of films may influence the effects of expressive suppression on memory. Results will be discussed in the context of previous literature concerning the effects of expressive suppression on cognition.
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Previously, studies investigating emotional face perception - regardless of whether they involved adults or children - presented participants with static photos of faces in isolation. In the natural world, faces are rarely encountered in isolation. In the few studies that have presented faces in context, the perception of emotional facial expressions is altered when paired with an incongruent context. For both adults and 8- year-old children, reaction times increase and accuracy decreases when facial expressions are presented in an incongruent context depicting a similar emotion (e.g., sad face on a fear body) compared to when presented in a congruent context (e.g., sad face on a sad body; Meeren, van Heijnsbergen, & de Gelder, 2005; Mondloch, 2012). This effect is called a congruency effect and does not exist for dissimilar emotions (e.g., happy and sad; Mondloch, 2012). Two models characterize similarity between emotional expressions differently; the emotional seed model bases similarity on physical features, whereas the dimensional model bases similarity on underlying dimensions of valence an . arousal. Study 1 investigated the emergence of an adult-like pattern of congruency effects in pre-school aged children. Using a child-friendly sorting task, we identified the youngest age at which children could accurately sort isolated facial expressions and body postures and then measured whether an incongruent context disrupted the perception of emotional facial expressions. Six-year-old children showed congruency effects for sad/fear but 4-year-old children did not for sad/happy. This pattern of congruency effects is consistent with both models and indicates that an adult-like pattern exists at the youngest age children can reliably sort emotional expressions in isolation. In Study 2, we compared the two models to determine their predictive abilities. The two models make different predictions about the size of congruency effects for three emotions: sad, anger, and fear. The emotional seed model predicts larger congruency effects when sad is paired with either anger or fear compared to when anger and fear are paired with each other. The dimensional model predicts larger congruency effects when anger and fear are paired together compared to when either is paired with sad. In both a speeded and unspeeded task the results failed to support either model, but the pattern of results indicated fearful bodies have a special effect. Fearful bodies reduced accuracy, increased reaction times more than any other posture, and shifted the pattern of errors. To determine whether the results were specific to bodies, we ran the reverse task to determine if faces could disrupt the perception of body postures. This experiment did not produce congruency effects, meaning faces do not influence the perception of body postures. In the final experiment, participants performed a flanker task to determine whether the effect of fearful bodies was specific to faces or whether fearful bodies would also produce a larger effect in an unrelated task in which faces were absent. Reaction times did not differ across trials, meaning fearful bodies' large effect is specific to situations with faces. Collectively, these studies provide novel insights, both developmentally and theoretically, into how emotional faces are perceived in context.
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Two experiments investigated effects of active processing of risk information on participants' understanding and judgments. It was hypothesized that more active processing would lead to better understanding and differences in affective judgments (e.g. increased satisfaction and reduced perceived risk to health). In both experiments participants were given a written scenario about their being prescribed a fictitious medication. This medication was said to cause side effects in 2% of people who took it. Before answering a series of written questions, participants in the active conditions of both experiments were asked to carry out a reflective task (portraying the size of risk on a bar chart in Experiment 1 and answering a reflective question in Experiment 2). The results showed that active participants rated the likelihood of experiencing possible side effects significantly lower than passive participants (Experiment 1), and that active participants were significantly more satisfied with the information and judged perceived risk to health from taking the medication significantly lower than passive participants (Experiment 2). In both experiments, active participants were significantly more correct in their probability and frequency estimates. The studies demonstrate that active processing of risk information leads to improved understanding of the information given. This has important implications for risk communication. In the context of health, better understanding should lead to improved decision-making and health outcomes. Copyright (C) 2004 John Wiley Sons, Ltd.
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While eye movements have been used widely to investigate how skilled adult readers process written language, relatively little research has used this methodology with children. This is unfortunate as, as we discuss here, eye-movement studies have significant potential to inform our understanding of children’s reading development. We consider some of the empirical and theoretical issues that arise when using this methodology with children, illustrating our points with data from an experiment examining word frequency effects in 8-year-old children’s sentence reading. Children showed significantly longer gaze durations to low than high-frequency words, demonstrating that linguistic characteristics of text drive children’s eye movements as they read. We discuss these findings within the broader context of how eye-movement studies can inform our understanding of children’s reading, and can assist with the development of appropriately targeted interventions to support children as they learn to read.
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Includes bibliography
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The purpose of this study was to investigate the effectiveness of implementing the Self-Regulated Strategy Development (SRSD) model of instruction (Graham & Harris, 2005; Harris & Graham, 1996) on the writing skills and writing self-regulation, attitudes, self-efficacy, and knowledge of 6 first grade students. A multiple-baseline design across participants with multiple probes (Kazdin, 2010) was used to test the effectiveness of the SRSD instructional intervention. Each participant was taught an SRSD story writing strategy as well as self-regulation strategies. All students wrote stories in response to picture prompts during the baseline, instruction, independent performance, and maintenance phases. Stories were assessed for essential story components, length, and overall quality. All participants also completed a writing attitude scale, a writing self-efficacy scale, and participated in brief interviews during the baseline and independent performance phases. Results indicated that SRSD can be beneficial for average first grade writers. Participants wrote stories that contained more essential components, were longer, and of better quality after SRSD instruction. Participants also showed some improvement in writing self-efficacy from pre- to post-instruction. All of the students maintained positive writing attitudes throughout the study.
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The purpose of the current study is to identify the impact of teaching students to revise their stories on writing production (Total Words Written; TWW), writing accuracy (Percent Correct Writing Sequences; %CWS), number of critical story elements included in stories, and quality of writing. Three third-grade and one fourth-grade student who were experiencing difficulties in the area of writing were involved in the study. The students were first taught to plan their stories using the evidence-based program, Self-Regulated Strategy Development (SRSD), which has frequently been implemented to teach students to plan their stories. Students were then taught to revise their stories using SRSD procedures modified for instruction in revision strategies. Student progress was evaluated through a multiple-probe design across tasks and a multiple-probe design across participants, which allowed for experimental control over time and across story probes. In addition to the previously mentioned variables, student’s acceptability of the intervention and their attitudes toward writing were also assessed. Results indicated that instruction in revising increased student writing accuracy beyond the effects of instruction in planning. Additionally, although instruction in planning was shown to increase writing production, number of critical story elements, and quality of writing, instruction in revising produced additional improvement in these variables as well. Finally, results indicated that students liked the intervention and their attitudes toward writing generally increased. Implications for practice and future research directions will be discussed. Advisor: Merilee McCurdy
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Glioblastoma multiforme (GBM) is the most common and most aggressive astrocytic tumor of the central nervous system (CNS) in adults. The standard treatment consisting of surgery, followed by a combinatorial radio- and chemotherapy, is only palliative and prolongs patient median survival to 12 to 15 months. The tumor subpopulation of stem cell-like glioma-initiating cells (GICs) shows resistance against radiation as well as chemotherapy, and has been suggested to be responsible for relapses of more aggressive tumors after therapy. The efficacy of immunotherapies, which exploit the immune system to specifically recognize and eliminate malignant cells, is limited due to strong immunosuppressive activities of the GICs and the generation of a specialized protective microenvironment. The molecular mechanisms underlying the therapy resistance of GICs are largely unknown. rnThe first aim of this study was to identify immune evasion mechanisms in GICs triggered by radiation. A model was used in which patient-derived GICs were treated in vitro with fractionated ionizing radiation (2.5 Gy in 7 consecutive passages) to select for a more radio-resistant phenotype. In the model cell line 1080, this selection process resulted in increased proliferative but diminished migratory capacities in comparison to untreated control GICs. Furthermore, radio-selected GICs downregulated various proteins involved in antigen processing and presentation, resulting in decreased expression of MHC class I molecules on the cellular surface and diminished recognition potential by cytotoxic CD8+ T cells. Thus, sub-lethal fractionated radiation can promote immune evasion and hamper the success of adjuvant immunotherapy. Among several immune-associated proteins, interferon-induced transmembrane protein 3 (IFITM3) was found to be upregulated in radio-selected GICs. While high expression of IFITM3 was associated with a worse overall survival of GBM patients (TCGA database) and increased proliferation and migration of differentiated glioma cell lines, a strong contribution of IFITM3 to proliferation in vitro as well as tumor growth and invasiveness in a xenograft model could not be observed. rnMultiple sclerosis (MS) is the most common autoimmune disease of the CNS in young adults of the Western World, which leads to progressive disability in genetically susceptible individuals, possibly triggered by environmental factors. It is assumed that self-reactive, myelin-specific T helper cell 1 (Th1) and Th17 cells, which have escaped the control mechanisms of the immune system, are critical in the pathogenesis of the human disease and its animal model experimental autoimmune encephalomyelitis (EAE). It was observed that in vitro differentiated interleukin 17 (IL-17) producing Th17 cells co-expressed the Th1-phenotypic cytokine Interferon-gamma (IFN-γ) in combination with the two respective lineage-associated transcription factors RORγt and T-bet after re-isolation from the CNS of diseased mice. Pathogenic molecular mechanisms that render a CD4+ T cell encephalitogenic have scarcely been investigated up to date. rnIn the second part of the thesis, whole transcriptional changes occurring in in vitro differentiated Th17 cells in the course of EAE were analyzed. Evaluation of signaling networks revealed an overrepresentation of genes involved in communication between the innate and adaptive immune system and metabolic alterations including cholesterol biosynthesis. The transcription factors Cebpa, Fos, Klf4, Nfatc1 and Spi1, associated with thymocyte development and naïve T cells were upregulated in encephalitogenic CNS-isolated CD4+ T cells, proposing a contribution to T cell plasticity. Correlation of the murine T-cell gene expression dataset to putative MS risk genes, which were selected based on their proximity (± 500 kb; ensembl database, release 75) to the MS risk single nucleotide polymorphisms (SNPs) proposed by the most recent multiple sclerosis GWAS in 2011, revealed that 67.3% of the MS risk genes were differentially expressed in EAE. Expression patterns of Bach2, Il2ra, Irf8, Mertk, Odf3b, Plek, Rgs1, Slc30a7, and Thada were confirmed in independent experiments, suggesting a contribution to T cell pathogenicity. Functional analysis of Nfatc1 revealed that Nfatc1-deficient CD4+ T cells were restrained in their ability to induce clinical signs of EAE. Nfatc1-deficiency allowed proper T cell activation, but diminished their potential to fully differentiate into Th17 cells and to express high amounts of lineage cytokines. As the inducible Nfatc1/αA transcript is distinct from the other family members, it could represent an interesting target for therapeutic intervention in MS.rn
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According to the broaden-and-build theory of positive emotions, positive emotions broaden while negative emotions narrow thought-action repertoires. These processes reflect changes in attentional scope, which is the focus of this research. The present study tested the hypothesis that participants in negative mood would be better able to focus on a target figure and separate it from its context in a perceptual task, and would also be better able to focus on the task amid a distracting environment than participants in a positive mood. An undergraduate sample of 77 participants watched video clips selected to induce either fear or amusement, and completed an Embedded Figures Test either in a quiet setting or in a noisy setting. A higher-order ANOVA revealed that Mood had a marginally significant effect on task performance, F(1, 73) = 3.94, p = .051, and that Distraction, F(1, 72) = 4.61, p = .035 and the Mood x Distraction interaction, F(1, 73) = 9.12, p = .003 did significantly affect task performance. However, contrary to the hypothesis, the effect of the distraction manipulation was greater for participants in a negative mood than it was for participants in a positive mood. The author suggests future directions to clarify the relationship between emotions, attentional scope, and susceptibility to environmental distraction.
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The general dopamine agonist apomorphine has been shown to have mostly facilitative effects on sexual behavior in rodents (Domingues & Hull, 2005; Bitran & Hull, 1987). A study looking at the effectsof apomorphine on sexual behavior in male golden hamsters observed that after systemic injections of apomorphine the males became aggressive towards the estrous females (Floody, unpublished). Studies on aggressive behavior have shown that apomorphine has facilitative effects on aggression in rodents (Nelson & Trainor, 2007; van Erp & Miczek, 2000; Ferrari, van Erp, Tornatzky, & Miczek, 2003). The studies presented here attempt to unravel the effects that apomorphine has on sexual and aggressive behavior in male golden hamsters. Studies 1, 2, 3, and 4 focused on the effects of apomorphine on aggression and Study 5 focused on the effects of apomorphine on sexual behavior. It was important for the purposes ofthis study to have separate, specific measures of aggression and sexual behavior that did not involve a social context that would involve multiple behaviors and motivations. The measure used to assessaggression was flank marking behavior. The measure used to assess sexual behavior was the number of vocalizations in response to sexual stimuli. The results from Studies 1, 2, and 3 suggested thatapomorphine increased aggressive motivation in a dose-dependent manner. In Studies 1 and 2 there was a high occurrence of stereotyped cheek pouching that interfered with the flank marking behavior. In Study 3 the procedure was modified to prevent cheek pouching and flank marking was observed uninhibited. Study 5 suggested a decrease in vocalizations after apomorphine treatment. However, this decrease may have been a result of the increase in stereotyped licking behavior. Results suggested that systemic apomorphine treatments increase aggressive motivation in hamsters. The increase in aggressive motivation may confuse the perception of the sensory signals that the males receive from the estrous females. They may haveperceived the estrous female as a nonestrous female which they would normally associate with an aggressive interaction (Lehman, Powers, & Winans, 1983).