Is the unilateral lesion of the left substantia nigra pars compacta sufficient to induce working memory impairment in rats?

Adult male Wistar rats with a substantia nigra pars compacta (SNc) lesion induced by intranigral administration of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used as a model of early phase Parkinson's disease (PD). This lesion caused a partial depletion of striatal dopamine (DA). The animals were submitted to a spatial working memory version of the water maze task in which they had to find a hidden (submersed) platform using online-maintained information that the platform remains in the same place during four consecutive trials, but that it is moved to another place every training day. Left, but not right SNc-lesioned rats were impaired in finding the platform in the second trial. This result suggests that the left SNc plays a key role in spatial working memory. Control experiments ruled out the possibility that motor impairment, sensory neglect, and/or impairment in the mental representation of the contralateral spatial environment had affected performance of the SNc-lesioned rats.     

System consolidation of memory during sleep

Over the past two decades, research has accumulated compelling evidence that sleep supports the formation of long-term memory. The standard two-stage memory model that has been originally elaborated for declarative memory assumes that new memories are transiently encoded into a temporary store (represented by the hippocampus in the declarative memory system) before they are gradually transferred into a long-term store (mainly represented by the neocortex), or are forgotten. Based on this model, we propose that sleep, as an offline mode of brain processing, serves the ‘active system consolidation’ of memory, i.e. the process in which newly encoded memory representations become redistributed to other neuron networks serving as long-term store. System consolidation takes place during slow-wave sleep (SWS) rather than rapid eye movement (REM) sleep. The concept of active system consolidation during sleep implicates that (a) memories are reactivated during sleep to be consolidated, (b) the consolidation process during sleep is selective inasmuch as it does not enhance every memory, and (c) memories, when transferred to the long-term store undergo qualitative changes. Experimental evidence for these three central implications is provided: It has been shown that reactivation of memories during SWS plays a causal role for consolidation, that sleep and specifically SWS consolidates preferentially memories with relevance for future plans, and that sleep produces qualitative changes in memory representations such that the extraction of explicit and conscious knowledge from implicitly learned materials is facilitated.     

Centrality of Event and Symptoms of Posttraumatic Stress Disorder After the 2011 Oslo Bombing Attack

It has been proposed that a highly integrated trauma leads to more accessible and vivid memories of the traumatic event, in turn heightening symptoms of posttraumatic stress disorder. The relationship between the centrality of a traumatic event and symptoms of posttraumatic stress disorder after the 2011 Oslo bombing attack was investigated in the present study. A high degree of perceived centrality was associated with higher symptom levels of posttraumatic stress as shown in the results. This association was found after controlling for gender, age and educational background. The relationship between types and level of trauma exposure, peritraumatic reactions and centrality of event was also investigated in the present study. Higher levels of trauma exposure and peritraumatic reactions were associated with higher levels of centrality of event as shown in the results. When a traumatic event becomes a reference point in the individual's life story and central to their identity, this is associated with an increased risk of symptomatology as suggested in the findings. Copyright © 2013 John Wiley & Sons, Ltd.     

Effect of Body Image on Tunisian Women’s Sexual Functioning

The objective of this study was to identify the perception of body image by Tunisian women and their spouses and to examine its impact on female sexuality. Our study involved 300 Tunisian women who had been married for at least 1 year and consulted in primary care medicine during the months of June and July 2016. Each participant completed a questionnaire covering four areas: women’s perception of their body, the perception of the spouses of the latter as it was reported by the participants, sexual activity, and the impact of body perception on sexual activity. The participants were satisfied with their bodies in 51% of cases. This satisfaction was associated with perceiving the body as physically attractive (p?=?0.007), young (p?=?0.047) and as a source of confidence (p?<?0.001). Compared to women dissatisfied with their bodies, those satisfied declared satisfaction of sexual desire (p?=?0.005), reaching orgasm (p?=?0.001), taking the initiative in sexual activity (p?=?0.003) and preparation for sex (p?=?0.006). Perceived satisfaction of the partner with the female body was related to a more positive sexuality in women, specifically to women’s sexual satisfaction (p?=?0.018), women taking sexual initiative (p?=?0.014) and preparation for sex (p?=?0.001). Our study indicates the important impact of a positive perception of the body image of Tunisian women by themselves and by their spouses on their sexuality. It would be interesting to consider these aspects in the management of female sexual disorders.     

Retrieval-induced forgetting after trauma: A study with victims of sexual assault

The Retrieval-Induced Forgetting (RIF) paradigm is used to study how the repeated retrieval practice of particular memories impairs the retrieval of related memory traces. A study is reported where this automatic form of forgetting was investigated in a group of sexual-assault victims and a control group. Using a recognition-cued RIF task, the present study examined RIF with neutral, positive, negative and trauma-specific stimuli. Response time data showed that irrespective of previous trauma exposure, a RIF effect was observed for neutral material, but not for emotional material. No differences in RIF between the trauma group and the control group were found. Inconsistencies with previous literature and the implications for emotional memory are discussed.     

Vivid memories of distant trauma: Examining the characteristics of trauma memories and the relationship with the centrality of event and posttraumatic stress 26 years after trauma

In the present study, we investigated the phenomenological characteristics of distant trauma memories and the relationship between the vividness of trauma memories, the centrality of event and symptoms of posttraumatic stress in two groups with different types of trauma exposure, namely survivors and bereaved, from the fire on the passenger ferry, Scandinavian Star, 26 years earlier. More than two decades after the fire, the traumatic event was represented as a vivid, emotional recollection for many of the victims. For both the survivors and the bereaved, a higher degree of vividness of trauma memories and centrality of the event were associated with higher levels of posttraumatic stress. The present findings show that even very distant trauma memories can be represented as vivid recollections. Furthermore, the findings suggest that both vividness of trauma memories and event centrality may contribute to explain how posttraumatic stress reactions can remain present over a very long time.     

The Implicit Image of God: God as Reality and Psychological Well‐Being

Research has widely demonstrated that religiosity is related to psychological well‐being even in situations of severe illness. To assess religious beliefs, explicit measures have generally been used. In this study, we measured the belief that God is reality as opposed to myth or abstraction by using an implicit technique (the Single Category Implicit Association Test). The study was carried out in Italy, where a large majority of the population is Catholic, and the prevailing image of God is that of a compassionate and supportive father. Participants were cancer patients identifying themselves as believers. As expected, the automatic belief that God is reality (vs. abstraction) was related to beneficial outcomes: lower reported psychophysical anxiety symptoms and a weaker use of avoidance strategies to cope with stress. Thus, also, automatic religious beliefs may affect feelings and behaviors.     

The Launching and Ensnaring Effects of Construing a Traumatic Event as Central to One's Identity and Life Story

Construing a traumatic event as central to one's life story and identity is associated with posttraumatic stress. The longitudinal relationship between centrality of event and trajectories of posttraumatic stress was examined. Data from ministerial employees were collected 10 months, 2 years, and 3 years after the 2011 Oslo bombing (N = 259). Using structural equation modeling, the launch and the snare hypotheses were tested. Support for the launch hypothesis was found; higher levels of event centrality 10 months after the attack were associated with higher levels of posttraumatic stress across time. Support for the snare hypothesis was also found; higher levels of centrality 10 months and 2 years after the bombing were related to higher levels of posttraumatic stress, beyond what could be anticipated based on the individual's general trajectory. This suggests that event centrality can influence the overall trajectory, and may also have additional time‐specific effects on posttraumatic stress.Copyright © 2016 John Wiley & Sons, Ltd.