Influence of sad mood induction on implicit self-esteem and its relationship with symptoms of depression and anxiety

Background and objectivesImplicit self-esteem (ISE) refers to the valence of triggered associations when the self is activated. Despite theories, previous studies often fail to observe low ISE in depression and anxiety. It is feasible that sad mood is required to activate dysfunctional self-associations. The present study tested the following hypotheses: i) ISE is lower following a sad mood induction (SMI); ii) the relationship between ISE and level of depression/anxiety symptoms is relatively strong when ISE is measured during sad mood; iii) individuals with higher levels of depression/anxiety symptoms will show a relatively large decrease in ISE following a SMI.MethodsIn this mixed-designed study, university students completed the self-esteem implicit association test (IAT) either at baseline (control condition; n = 46) or following a SMI (experimental condition; n = 49). To test the third hypothesis, a SMI and IAT were also given in the control condition. Both conditions completed self-report measures of explicit self-esteem (ESE), and symptoms of depression and anxiety.ResultsThere was no support for the first two hypotheses, but some support that symptoms of anxiety correlated with larger decreases in ISE following a SMI which partly supported the third hypothesis. This disappeared when controlling for multiple testing.LimitationsResults are limited to non-clinical participants.ConclusionsWhile ISE was robust against increases in sad mood, there was some tentative support that symptoms of anxiety were related to larger decreases in ISE following a SMI

Collaboration enhances later individual memory for emotional material

Research on collaborative remembering suggests that collaboration hampers group memory (i.e., collaborative inhibition), yet enhances later individual memory. Studies examining collaborative effects on memory for emotional stimuli are scarce, especially concerning later individual memory. In the present study, female undergraduates watched an emotional movie and recalled it either collaboratively (n=60) or individually (n=60), followed by an individual free recall test and a recognition test. We replicated the standard collaborative inhibition effect. Further, in line with the literature, the collaborative condition displayed better post-collaborative individual memory. More importantly, in post-collaborative free recall, the centrality of the information to the movie plot did not play an important role. Recognition rendered slightly different results. Although collaboration rendered more correct recognition for more central details, it did not enhance recognition of background details. Secondly, the collaborative and individual conditions did not differ with respect to overlap of unique correct items in free recall. Yet, during recognition former collaborators more unanimously endorsed correct answers, as well as errors. Finally, extraversion, neuroticism, social anxiety, and depressive symptoms did not moderate the influence of collaboration on memory. Implications for the fields of forensic and clinical psychology are discussed

Pre-Stressor Interference Control and Intrusive Memories

Although intrusive imagery is a common response in the aftermath of a stressful or traumatic event, only a minority of trauma victims show persistent re-experiencing and related psychopathology. Individual differences in pre-trauma executive control possibly play a critical role. Therefore, this study investigated whether a relatively poor pre-stressor ability to resist proactive interference in working memory might increase risk for experiencing undesirable intrusive memories after being exposed to a stressful event. Non-clinical participants (N = 85) completed a modified version of a widely used test of interference control in working memory (CVLT; Kramer and Delis 1991) and subsequently watched an emotional film fragment. Following presentation of the fragment, intrusive memories were recorded in a 1-week diary and at a follow up session 7 days later. A relatively poor ability to resist proactive interference was related to a relatively high frequency of film-related intrusive memories. This relationship was independent of neuroticism and gender. These findings are consistent with the idea that a pre-morbid deficit in the ability to resist proactive interference reflects a vulnerability factor for experiencing intrusive memories after trauma exposure

Neuronal differentiation of hair-follicle-bulge-derived stem cells co-cultured with mouse cochlear modiolus explants

Stem-cell-based repair of auditory neurons may represent an attractive therapeutic option to restore sensorineural hearing loss. Hair-follicle-bulge-derived stem cells (HFBSCs) are promising candidates for this type of therapy, because they (1) have migratory properties, enabling migration after transplantation, (2) can differentiate into sensory neurons and glial cells, and (3) can easily be harvested in relatively high numbers. However, HFBSCs have never been used for this purpose. We hypothesized that HFBSCs can be used for cell-based repair of the auditory nerve and we have examined their migration and incorporation into cochlear modiolus explants and their subsequent differentiation. Modiolus explants obtained from adult wild-type mice were cultured in the presence of EF1α-copGFP-transduced HFBSCs, constitutively expressing copepod green fluorescent protein (copGFP). Also, modiolus explants without hair cells were co-cultured with DCX-copGFP-transduced HFBSCs, which demonstrate copGFP upon doublecortin expression during neuronal differentiation. Velocity of HFBSC migration towards modiolus explants was calculated, and after two weeks, co-cultures were fixed and processed for immunohistochemical staining. EF1α-copGFP HFBSC migration velocity was fast: 80.5 ± 6.1 μm/h. After arrival in the explant, the cells formed a fascicular pattern and changed their phenotype into an ATOH1-positive neuronal cell type. DCX-copGFP HFBSCs became green-fluorescent after integration into the explants, confirming neuronal differentiation of the cells. These results show that HFBSC-derived neuronal progenitors are migratory and can integrate into cochlear modiolus explants, while adapting their phenotype depending on this micro-environment. Thus, HFBSCs show potential to be employed in cell-based therapies for auditory nerve repair

Distractibility and individual differences in the experience of involuntary memories

The present study explored the idea that the tendency to experience intrusive memories might be associated with relatively weak cognitive control in general as indexed by the general propensity to become distracted by irrelevant information. A sample of undergraduate students (N = 413) filled in self-report measures of involuntary memories, distractibility, depression and repressive coping. The results showed a significant relation between involuntary memories and distractibility, independent of both trait depression and repressive coping, indicating a general vulnerability factor. As cognitive control may be sensitive to circadian variation, time of day effects in the experience of intrusions were also explored. No significant relation emerged. A proposed relationship between deficient inhibitory mechanisms of working memory and vulnerability for developing and maintaining intrusive memories after experiencing a stressful event is also discussed. (c) 2006 Elsevier Ltd. All rights reserved

The crippling homunculus: inefficient executive control and the persistence of intrusive memories

Research has shown that about two-third of the general population will be exposed to a traumatic event at least once in their lives. The emotional impact of a traumatic event (e.g., a major traffic accident) may largely disrupt normal memory functioning. In the aftermath of trauma, most people are confronted with unexpected and unwanted reliving experiences of parts of the event, commonly known as intrusive memories. These mainly visual images are accompanied with strong emotional responses (e.g., fear, shame), which could hinder normal daily life for weeks. After some time, the majority of the trauma survivors will be able to gain control over the stressful intrusive memories and refocus their attention on work and family life. However, a small number of the survivors would show a persistence of intrusive re-experiencing for months or even years. This group would eventually develop a posttraumatic stress disorder (PTSD). This raises the question of how this difference in control between people who show natural recovery and people with persistent intrusions and PTSD could be explained. The key question of this dissertation was whether an innate or early acquired flexibility/capacity to resist unwanted information from consciousness would contribute to regaining control over disruptive memory functioning and support natural recovery after trauma. In five analogue studies (using undergraduates as research participants), it was shown that flexible control over the contents of consciousness prior to experiencing a stressful event (e.g., a trauma-film) would provide people the tools to reduce the frequency of intrusive memories after trauma.