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Description
Intermittent social defeat stress induces cross-sensitization to psychostimulants and escalation of drug self-administration. These behaviors could result from the stress-induced neuroadaptation in the mesocorticolimbic dopamine circuit. Brain-derived neurotrophic factor (BDNF) in the ventral tegmental area (VTA) is persistently elevated after social defeat stress, and may contribute to the stress-induced neuroadaptation in the mesocorticolimbic dopamine circuit. BDNF modulates synaptic plasticity, and facilitates stress- and drug-induced neuroadaptations in the mesocorticolimbic system. The present research examined the role of mesolimbic BDNF signaling in social defeat stress-induced cross-sensitization to psychostimulants and the escalation of cocaine self-administration in rats. We measured drug taking behavior with the acquisition, progressive ratio, and binge paradigms during self-administration. With BDNF overexpression in the ventral tegmental area (VTA), single social defeat stress-induced cross-sensitization to amphetamine (AMPH) was significantly potentiated. VTA-BDNF overexpression also facilitates acquisition of cocaine self-administration, and a positive correlation between the level of VTA BDNF and drug intake during 12 hour binge was observed. We also found significant increase of DeltaFosB expression in the nucleus accumbens (NAc), the projection area of the VTA, in rats received intra-VTA BDNF overexpression. We therefore examined whether BDNF signaling in the NAc is important for social defeat stress-induced cross-sensitization by knockdown of the receptor of BDNF (neurotrophin tyrosine kinase receptor type 2, TrkB) there. NAc TrkB knockdown prevented social defeat stress-induced cross-sensitization to psychostimulant. Also social defeat stress-induced increase of DeltaFosB in the NAc was prevented by TrkB knockdown. Several other factors up-regulated by stress, such as the GluA1 subunit of Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor and BDNF in the VTA were also prevented. We conclude that BDNF signaling in the VTA increases social defeat stress-induced vulnerability to psychostimulants, manifested as potentiated cross-sensitization/sensitization to AMPH and escalation of cocaine self-administration. Also BDNF signaling in the NAc is necessary for the stress-induced neuroadaptation and behavioral sensitization to psychostimulants. Therefore, TrkB in the NAc could be a therapeutic target to prevent stress-induced vulnerability to drugs of abuse in the future. DeltaFosB in the NAc shell could be a neural substrate underlying persistent cross-sensitization and augmented cocaine self-administration induced by social defeat stress.
ContributorsWang, Junshi (Author) / Hammer, Ronald (Thesis advisor) / Feuerstein, Burt (Committee member) / Nikulina, Ella (Committee member) / Neisewander, Janet (Committee member) / Arizona State University (Publisher)
Created2013
Description
Previous research indicates that difficulties in emotion regulation and greater dissociation from one's emotions are often observed among trauma survivors. Further, trauma survivors often show greater negative emotions such as anger, and diminished positive emotions such as happiness. Relatively less is known about the relationship between posttraumatic stress symptoms, dissociation, emotion regulation difficulties, and non-trauma related emotional experiences in daily life. This study examined whether greater reports of posttraumatic stress symptoms, difficulties in emotion regulation, and dissociative tendencies were associated with greater intensity of anger and lower intensity of happiness during a relived emotions task (i.e., recalling and describing autobiographical memories evoking specific emotions). Participants were 50 individuals who had experienced a traumatic event and reported a range of posttraumatic stress symptoms. Participants rated how they felt while recalling specific emotional memories, as well as how they remembered feeling at the time of the event. Results showed that dissociative tendencies was the best predictor of greater intensity of anger and, contrary to the hypothesis, dissociative tendencies was predictive of greater happiness intensity as well. These findings are consistent with previous research indicating a paradoxical effect of heightened anger reactivity among individuals with dissociative tendencies. In addition, researchers have argued that individuals with a history of traumatization do not report lower positive emotional experiences. The present findings may suggest the use of dissociation as a mechanism to avoid certain trauma related emotions (e.g, fear and anxiety), in turn creating heightened experiences of other emotions such as anger and happiness.
ContributorsTorres, Dhannia L (Author) / Robinson Kurpius, Sharon (Thesis advisor) / Roberts, Nicole A. (Committee member) / Homer, Judith (Committee member) / Arizona State University (Publisher)
Created2013
Description
Courthouse dogs (sometimes referred to as facility animals) are expertly trained canines which may be used to assist individuals with psychological, emotional, or physical difficulties in a myriad of courtroom situations. While these animals are increasingly used to assist young witness to court, the jury is still out on whether or not they are prejudicial to the defendant. No known research exists in this area, although research is necessary to determine the possibly prejudicial nature of these animals. Using a mock trial paradigm involving a child sexual abuse case, the current study employed a 2 (Witness type: victim vs. bystander) x 3 (Innovation type: courthouse dog vs. teddy bear vs. none) fully-crossed factorial design. It was hypothesized that witness type and innovation type would interact to differentially impact jurors' judgments about the trial, defendant, and child witness. In addition, it was posited that emotions, such as anger and disgust, would also affect judgments and decision-making. Results indicate that courthouse dogs and comfort toys did impact jurors' decision making in some ways. In addition, emotions and witness credibility predicted sentencing, verdict, and other trial judgments.
ContributorsBurd, Kayla (Author) / Mcquiston, Dawn E (Thesis advisor) / Salerno, Jessica M (Committee member) / Schweitzer, Nicholas J (Committee member) / Arizona State University (Publisher)
Created2013
Description
In the past decade, research has demonstrated the relationship between higher levels of self-compassion and lower levels of negative psychological outcomes. More recently, the concept of self-compassion has been explored within the context of various health behaviors. Very few studies have investigated the potential relationship between self-compassion and eating behaviors. Based on literature and the established relationship between negative self-evaluation and abnormal eating behaviors/eating disorders, the current study sought to examine correlations between self-compassion, eating behaviors, and stress in first time college freshmen. The study population consisted of 1478 participants; ages 18-22 years; females = 936 (63%), males = 541 (37%). Participants self-reported measures of the Perceived Stress Scale (PSS), the Three Factor Eating Questionnaire (TFEQ), and the Self Compassion Scale (SCS). PSS score, the overall score and individual subscale scores of SCS, and the three subscale scores of the TFEQ (restraint, disinhibiton, hunger) were examined with Pearson correlations. Results of this study indicate significant (p = < .05) differences between males and females in PSS and all three negative SCS subscales. There was a strong and consistent correlation between the eating behavior of disinhibition and all three negative constructs of self-compassion (self-judgment, r = .29; isolation, r = .23; over-identification, r = .28) in females. The eating behavior of restraint was similarly correlated with SCS self-judgment in females (r = .26). More research is needed to understand differences in stress, self-compassion, and eating behaviors between males and females and to better comprehend the weak associations between eating behaviors and the positive psychological constructs of self-compassion (self-kindness, common humanity, and mindfulness) for males and females. Additionally, future research should focus on the three subscales of disinhibition as they relate to the negative constructs of self-compassion. The preliminary results of this study suggest it would be beneficial, particularly to female college freshmen, to more fully understand the dynamics of the relationship between eating behaviors and self-compassion; this knowledge may help to better structure appropriate coping strategies for the prevention of disordered eating behaviors.
ContributorsJames, Darith (Author) / Sebren, Ann (Thesis advisor) / Swan, Pamela D. (Committee member) / Der Ananian, Cheryl (Committee member) / Arizona State University (Publisher)
Created2013
Description
The objective of this study was to examine the potential effects of long term hormone replacement therapy on cardiovascular autonomic nervous system responses to laboratory social stressors. The participants were 38 postmenopausal women, 18 using estrogen and progesterone hormone replacement therapy for at least 2 years and 20 control participants without hormone replacement therapy. All women completed orthostasis (standing and sitting), then speech and math tasks (speech and math were counterbalanced). Cardiovascular measures of sympathetic nervous system (pre-ejection period, PEP) and parasympathetic nervous system (respiratory sinus arrhythmia, RSA) along with heart rate were collected throughout all periods (baseline, orthostasis, and stressors). For orthostasis, results of mixed analyses of variance (ANOVAs) showed expected period effects for heart rate, RSA and PEP, but no group or group by period interaction was significant. For the psychological stressors, period main effects were significant for all three variables, suggesting that the tasks were effective at inducing stress. Also, there was a significant interaction between group and period for RSA, demonstrated by greater decrease during the psychological stressor period in the group using HRT. The interactions between group and period for heart rate and PEP were non-significant. These findings support the notion that HRT may slow age-related decreases in parasympathetic responsiveness. Furthermore, changes in vagal reactivity in relation to use of HRT appear to occur within mechanisms involving response and coping with psychological stressors, rather than mechanisms that accommodate basic physiological task such as orthostasis.
ContributorsValancova-Acevedo, Katarina (Author) / Burleson, Mary H. (Thesis advisor) / Roberts, Nicole A. (Committee member) / Newman, Matt L. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Research has shown that a developmental process of maturing out of alcohol involvement occurs during young adulthood, and that this process is related to both young adult role transitions (e.g., marriage) and personality developmental (e.g., decreased disinhibition and neuroticism). The current study extended past research by testing whether protective marriage and personality effects on maturing out were stronger among more severe late adolescent drinkers, and whether protective marriage effects were stronger among those who experienced more personality development. Parental alcoholism and gender were tested as moderators of marriage, personality, and late adolescent drinking effects on maturing out; and as distal predictors mediated by these effects. Participants were a subsample (N = 844; 51% children of alcoholics; 53% male, 71% non-Hispanic Caucasian, 27% Hispanic; Chassin, Barrera, Bech, & Kossak-Fuller, 1992) from a larger longitudinal study of familial alcoholism. Hypotheses were tested with latent growth models characterizing alcohol consumption and drinking consequence trajectories from late adolescence to adulthood (age 17-40). Past findings were replicated by showing protective effects of becoming married, sensation-seeking reductions, and neuroticism reductions on the drinking trajectories. Moderation tests showed that protective marriage effects on the drinking trajectories were stronger among those with higher pre-marriage drinking in late adolescence (i.e., higher growth intercepts). This might reflect role socialization mechanisms such that more severe drinking produces more conflict with the demands of new roles (i.e., role incompatibility), thus requiring greater drinking reductions to resolve this conflict. In contrast, little evidence was found for moderation of personality effects by late adolescent drinking or for moderation of marriage effects by personality. Parental alcoholism findings suggested complex moderated mediation pathways. Parental alcoholism predicted less drinking reduction through decreasing the likelihood of marriage (mediation) and muting marriage's effect on the drinking trajectories (moderation), but parental alcoholism also predicted more drinking reduction through increasing initial drinking in late adolescence (mediation). The current study provides new insights into naturally occurring processes of recovery during young adulthood and suggests that developmentally-tailored interventions for young adults could harness these natural recovery processes (e.g., by integrating role incompatibility themes and addressing factors that block role effects among those with familial alcoholism).
ContributorsLee, Matthew R. (Author) / Chassin, Laurie (Thesis advisor) / Corbin, William R. (Committee member) / Mackinnon, David P (Committee member) / Presson, Clark C. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Perceptual learning by means of coherent motion training paradigms has been shown to produce plasticity in lower and higher-level visual systems within the human occipital lobe both supra- and subliminally. However, efficiency of training methods that produce consolidation in the visual system via coherent motion has yet to be experimentally determined. Furthermore, the effects of coherent motion training on reading comprehension, in clinical and normal populations, are still nascent. In the present study, 20 participants were randomly assigned to one of four experimental conditions. Two conditions had a participation requirement of four days while two conditions required eight days of participation. These conditions were further divided into 500 or 1000 trials per day (4 x 500, 4 x 1000, 8 x 500, 8 x 1000). Additional pre-test and post-test days were used to attain timed pre- and post-tests on the Wide Range Achievement Test IV (WRAT IV) reading comprehension battery. Furthermore, a critical flicker fusion threshold (CFFT) score was taken on a macular pigment densitometer on the pre-test and post-test day. Participants showed significant improvement in CFFT levels, WRAT IV reading comprehension, and speed of completion between pre-test and post-test; however, degree of improvement did not vary as a function of training condition. An interaction between training condition and degree of improvement was evident in coherent dot motion contrast scores, with significant training plasticity occurring in the 4 x 1000 and 8 x 500 conditions.
ContributorsGroth, Anthony (Author) / Náñez, José E. (Thesis advisor) / Hall, Deborah (Committee member) / Risko, Evan F. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Niche variation among sexes and life stages within a population has been documented in many species, yet few studies have investigated niche variation within demographic groups or across ecological contexts. We examined the extent to which pregnant California sea lions (Zalophus californianus) at each of three breeding colonies target alternative prey resources and habitats. The three colonies are distributed across distinct regions of the Gulf of California, Mexico and have divergent population dynamics. We compared the nature of niche variation among colonies and investigated the fitness consequences of different foraging strategies within each colony. We analyzed the δ13C and δ15N values from fur collected from 206 suckling pups to characterize relative maternal foraging locations (δ13C) and trophic levels (δ15N) during the metabolically demanding late stages of gestation and lactation that occur simultaneously in California sea lions. The δ13C and δ15N values were regressed against pup body condition index values to compare the relative individual-level fitness benefits of different maternal foraging strategies. We found that the nature and extent of niche variation differed among colonies. Niche variation was most pronounced at the two largest colonies that appear to experience the highest levels of intraspecific competition and the variation was consistent with habitat features. One colony (Granito) displayed two distinct foraging groups with indistinguishable median pup body condition values, whereas the second (San Jorge) exhibited continuous niche variation and pup body condition varied in relation to maternal foraging location and trophic level, suggesting disparities among alternative foraging strategies. For the smallest colony (Los Islotes), females occupy similar niches with a few outliers. Body condition values of pups at this colony were most variable, but did not vary with maternal foraging strategy. Our results provide evidence for intrapopulation niche variation among demographically similar individuals during a period of high metabolic stress and reproductive importance. This work suggests possible fitness benefits conferred by alternative foraging strategies, and calls into question the common assumption that members of a population are ecologically equivalent. Future research aimed at understanding animal foraging strategies should consider the nature and extent of niche variation in the context of local ecological conditions.
ContributorsCrawford, Tara Gancos (Author) / Gerber, Leah R. (Thesis advisor) / Ogle, Kiona (Committee member) / Kurle, Carolyn M (Committee member) / Arizona State University (Publisher)
Created2013
Description
Frequency effects favoring high print-frequency words have been observed in frequency judgment memory tasks. Healthy young adults performed frequency judgment tasks; one group performed a single task while another group did the same task while alternating their attention to a secondary task (mathematical equations). Performance was assessed by correct and error responses, reaction times, and accuracy. Accuracy and reaction times were analyzed in terms of memory load (task condition), number of repetitions, effect of high vs. low print-frequency, and correlations with working memory span. Multinomial tree analyses were also completed to investigate source vs. item memory and revealed a mirror effect in episodic memory experiments (source memory), but a frequency advantage in span tasks (item memory). Interestingly enough, we did not observe an advantage for high working memory span individuals in frequency judgments, even when participants split their attention during the dual task (similar to a complex span task). However, we concluded that both the amount of attentional resources allocated and prior experience with an item affect how it is stored in memory.
ContributorsPeterson, Megan Paige (Author) / Azuma, Tamiko (Thesis advisor) / Gray, Shelley (Committee member) / Liss, Julie (Committee member) / Arizona State University (Publisher)
Created2013
Description
Juvenile offenders suffer from substance use disorders at higher rates than adolescents in the general public. Substance use disorders also predict an increased risk for re-offending. Therefore, it is important that these juveniles, in particular, receive the appropriate substance use disorder treatment. The present study used logistic regression to test whether race/ethnicity would moderate the match between substance use disorder diagnosis and the receipt of a substance use disorder related service in a sample of male, serious juvenile offenders. Results showed that among those with a substance use disorder diagnosis, there were no race/ethnicity differences in the receipt of the appropriate service. However, among those without a substance use disorder diagnosis, non-Hispanic Caucasians were more likely to receive substance use service than were Hispanics or African-Americans. Post-hoc analyses revealed that when using a broader definition of substance use problems, significant differences by race/ethnicity in the prediction of service receipt were only observed at low levels of substance use problems. These findings shed light on how race/ethnicity may play a role in the recommendation of substance use disorder services in the juvenile justice system.
ContributorsMansion, Andre (Author) / Chassin, Laurie (Thesis advisor) / Dishion, Thomas (Committee member) / Knight, George (Committee member) / Arizona State University (Publisher)
Created2013