Individual differences in spatial configuration learning predict the occurrence of intrusive memories

The dual-representation model of posttraumatic stress disorder (PTSD; Brewin, Gregory, Lipton, & Burgess, Psychological Review, 117, 210-232 2010) argues that intrusions occur when people fail to construct context-based representations during adverse experiences. The present study tested a specific prediction flowing from this model. In particular, we investigated whether the efficiency of temporal-lobe-based spatial configuration learning would account for individual differences in intrusive experiences and physiological reactivity in the laboratory. Participants (N = 82) completed the contextual cuing paradigm, which assesses spatial configuration learning that is believed to depend on associative encoding in the parahippocampus. They were then shown a trauma film. Afterward, startle responses were quantified during presentation of trauma reminder pictures versus unrelated neutral and emotional pictures. PTSD symptoms were recorded in the week following participation. Better configuration learning performance was associated with fewer perceptual intrusions, r = ?.33, p < .01, but was unrelated to physiological responses to trauma reminder images (ps > .46) and had no direct effect on intrusion-related distress and overall PTSD symptoms, rs > ?.12, ps > .29. However, configuration learning performance tended to be associated with reduced physiological responses to unrelated negative images, r = ?.20, p = .07. Thus, while spatial configuration learning appears to be unrelated to affective responding to trauma reminders, our overall findings support the idea that the context-based memory system helps to reduce intrusions.     

Slashing Smallville: The Interplay of Text, Audience and Production on Viewer Interpretations of Homoeroticism

This essay examines the slash community surrounding the television series Smallville. Utilizing textual data, audience survey responses, and fan ethnography, I locate the performance of homoeroticism in Smallville and highlight important (sub)textual moments of the series as recounted by participants. These observations reveal important implications concerning the performative capabilities of narrative, the cultural significance of this particular Superman retelling, and the influence of textual intent on subcultural practices related to the gay, lesbian, bisexual and transgender community. In essence, slash fans create an alternative vision of television narrative by marking each characters’ actions as homoerotic, which is rearticulated by the writers, directors and actors of the series. This interplay illustrates the changing nature of television narrative, where text, audience and production are inseparable when analyzing media artifacts.     

Fractal Dynamics of Heart Beat Interval Fluctuations in Corticotropin-Releasing Factor Receptor Subtype 2 Deficient Mice

Non-linear fractal analysis of cardiac interbeat time series was performed in corticotropin-releasing factor receptor subtype 2 (CRFR2) deficient mice. Heart rate dynamics in mice constitutes a self-similar, scale-invariant, random fractal process with persistent intrinsic long-range correlations and inverse power-law properties. We hypothesized that the sustained tachycardic response elicited by intraperitoneal (ip) injection of human/rat CRF (h/rCRF) is mediated by CRFR2. In wildtype control animals, heart rate was increased to about maximum levels (approximately 750 bpm) while in CRFR2-deficient animals baseline values were retained (approximately 580 bpm). The tachycardic response elicited by ip-application is mediated by CRFR2 and is interpreted to result from sympathetic stimulation. However, the functional integrity of CRFR2 would not present a prerequisite to maintaining the responsiveness and resiliency of cardiac control to external environmental perturbations experimentally induced by extrinsic ip-application of h/rCRF or under physiological conditions that may be associated with an increased peripheral release of CRF. Under stressful physiological conditions achieved by novelty exposure, CRFR2 is not involved in the cardiodynamic regulation to external short-term stress. While the hypothesis of involvement of CRFR2 in cardiac regulation upon pharmacological stimulation cannot be rejected, the present findings suggest that the mechanism of action is by sympathetic stimulation, but would not unambiguously allow to draw any conclusions as to the physiological role of CRFR2 in the control of cardiac dynamics.     

Evaluation of the Responding in Peaceful and Positive Ways (RIPP) Seventh Grade Violence Prevention Curriculum

We evaluated the impact of RIPP-7, a seventh grade violence prevention curriculum designed to strengthen and extend the effects of the sixth grade RIPP-6 curriculum. Classes of seventh graders at two urban middle schools serving predominantly African-American youth where RIPP-6 had been implemented the preceding school year were randomized to intervention (N = 239) and control groups (N = 237). Compared to students in the control group, students who participated in RIPP-7 had fewer disciplinary code violations for violent offenses during the following school year. A limited number of main effects were found on self-report outcome measures and measures of attitudes. Although significant main effects were not found on self-report measures of physical aggression, drug use, or anxiety, analyses of interactions with pretest scores indicated that intervention effects were significantly moderated by pretest scores for several outcome measures. Students most likely to benefit from the intervention were those who reported higher pretest rates of problem behaviors including violent behavior, nonphysical aggression, and delinquent behavior.     

Map-based navigation in mobile robots:: II. A review of map-learning and path-planning strategies

This article reviews map-learning and path-planning strategies within the context of map-based navigation in mobile robots. Concerning map-learning, it distinguishes metric maps from topological maps and describes procedures that help maintain the coherency of these maps. Concerning path-planning, it distinguishes continuous from discretized spaces and describes procedures applicable when the execution of a plan fails. It insists on the need for an integrated conception of such procedures, which must be tightly tailored to the specific robot that is used, notably to the capacities and limitations of its sensory-motor equipment, and to the specific environment that is experienced. A hierarchy of navigation strategies is outlined in the discussion, together with the sort of adaptive capacities each affords to cope with unexpected obstacles or dangers encountered on an animat or robot’s way to its goal.     

Pregnancy-specific stress, prenatal health behaviors, and birth outcomes

OBJECTIVE: Stress in pregnancy predicts earlier birth and lower birth weight. The authors investigated whether pregnancy-specific stress contributes uniquely to birth outcomes compared with general stress, and whether prenatal health behaviors explain this association. DESIGN: Three structured prenatal interviews (N = 279) assessing state anxiety, perceived stress, life events, pregnancy-specific stress, and health behaviors. MAIN OUTCOME MEASURES: Gestational age at delivery, birth weight, preterm delivery (<37 weeks), and low birth weight (<2,500 g). RESULTS: A latent pregnancy-specific stress factor predicted birth outcomes better than latent factors representing state anxiety, perceived stress, or life event stress, and than a latent factor constructed from all stress measures. Controlling for obstetric risk, pregnancy-specific stress was associated with smoking, caffeine consumption, and unhealthy eating, and inversely associated with healthy eating, vitamin use, exercise, and gestational age at delivery. Cigarette smoking predicted lower birth weight. Clinically-defined birth outcomes were predicted by cigarette smoking and pregnancy-specific stress. CONCLUSION: Pregnancy-specific stress contributed directly to preterm delivery and indirectly to low birth weight through its association with smoking. Pregnancy-specific stress may be a more powerful contributor to birth outcomes than general stress.