Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment

Community-based studies suggest that cannabis products that are high in Δ⁹-tetrahydrocannabinol (THC) but low in cannabidiol (CBD) are particularly hazardous for mental health. Laboratory-based studies are ideal for clarifying this issue because THC and CBD can be administered in pure form, under controlled conditions. In a between-subjects design, we tested the hypothesis that pre-treatment with CBD inhibited THC-elicited psychosis and cognitive impairment. Healthy participants were randomised to receive oral CBD 600 mg (n=22) or placebo (n=26), 210 min ahead of intravenous (IV) THC (1.5 mg). Post-THC, there were lower PANSS positive scores in the CBD group, but this did not reach statistical significance. However, clinically significant positive psychotic symptoms (defined a priori as increases ≥ 3 points) were less likely in the CBD group compared with the placebo group, odds ratio (OR)=0.22 (χ²=4.74, p<0.05). In agreement, post-THC paranoia, as rated with the State Social Paranoia Scale (SSPS), was less in the CBD group compared with the placebo group (t=2.28, p<0.05). Episodic memory, indexed by scores on the Hopkins Verbal Learning Task-revised (HVLT-R), was poorer, relative to baseline, in the placebo pre-treated group (-10.6 ± 18.9%) compared with the CBD group (-0.4% ± 9.7 %) (t=2.39, p<0.05). These findings support the idea that high-THC/low-CBD cannabis products are associated with increased risks for mental health.

Stress effects on working memory, explicit memory, and implicit memory for neutral and emotional stimuli in healthy men

Stress is a strong modulator of memory function. However, memory is not a unitary process and stress seems to exert different effects depending on the memory type under study. Here, we explored the impact of social stress on different aspects of human memory, including tests for explicit memory and working memory (for neutral materials), as well as implicit memory (perceptual priming, contextual priming and classical conditioning for emotional stimuli). A total of 35 young adult male students were randomly assigned to either the stress or the control group, with stress being induced by the Trier Social Stress Test (TSST). Salivary cortisol levels were assessed repeatedly throughout the experiment to validate stress effects. The results support previous evidence indicating complex effects of stress on different types of memory: A pronounced working memory deficit was associated with exposure to stress. No performance differences between groups of stressed and unstressed subjects were observed in verbal explicit memory (but note that learning and recall took place within 1 h and immediately following stress) or in implicit memory for neutral stimuli. Stress enhanced classical conditioning for negative but not positive stimuli. In addition, stress improved spatial explicit memory. These results reinforce the view that acute stress can be highly disruptive for working memory processing. They provide new evidence for the facilitating effects of stress on implicit memory for negative emotional materials. Our findings are discussed with respect to their potential relevance for psychiatric disorders, such as post traumatic stress disorder.

The effects of resistance training on well-being and memory in eldery volunteers

Objective: to determine the short- and long-term effects of resistance training on muscle strength, psychological well-being, control-beliefs, cognitive speed and memory in normally active elderly people. Methods: 46 elderly people (mean age 73.2 years; 18 women and 28 men), were randomly assigned to training and control groups (n = 23 each). Pre- and post-tests were administered 1 week before and 1 week after the 8-week training intervention. The training sessions, performed once a week, consisted of a 10 min warm-up phase and eight resistance exercises on machines. Results: there was a significant increase in maximum dynamic strength in the training group. This training effect was associated with a significant decrease in self-attentiveness, which is known to enhance psychological well-being. No significant changes could be observed in control-beliefs. Modest effects on cognitive functioning occurred with the training procedure: although there were no changes in cognitive speed, significant pre/post-changes could be shown in free recall and recognition in the experimental group. A post-test comparison between the experimental group and control group showed a weak effect for recognition but no significant differences in free recall. Significant long-term effects were found in the training group for muscular strength and memory performance (free recall) 1 year later. Conclusion: an 8-week programme of resistance training lessens anxiety and self-attentiveness and improves muscle strength.

Improving memory in elderly adults by instructing them in professional actors' learning strategies

This study examined a new type of cognitive intervention. For four weeks, participants (ages 65 to 82) were instructed in professional acting techniques, followed by rehearsal and performance of theatrical scenes. Although the training was not targeted in any way to the tasks used in pre- and post-testing, participants produced significantly higher recall and recognition scores after the intervention. It is suggested that the cognitive effort involved in analyzing and adopting theatrical characters' motivations (and then experiencing those characters' mental/emotional states during performance) is responsible for the observed improvement. A secondary strand of this study showed that participants who were given annotated scripts in which the implied goals of the characters were made explicit demonstrated significantly faster access to the stored material, as measured by a computer latency task.

From episodic to habitual prospective memory: ERP-evidence for a linear transition

Performing a prospective memory task repeatedly changes the nature of the task from episodic to habitual. The goal of the present study was to investigate the neural basis of this transition. In two experiments, we contrasted event-related potentials (ERPs) evoked by correct responses to prospective memory targets in the first, more episodic part of the experiment with those of the second, more habitual part of the experiment. Specifically, we tested whether the early, middle, or late ERP-components, which are thought to reflect cue detection, retrieval of the intention, and post-retrieval processes, respectively, would be changed by routinely performing the prospective memory task. The results showed a differential ERP effect in the middle time window (450 - 650 ms post-stimulus). Source localization using low resolution brain electromagnetic tomography analysis (LORETA) suggests that the transition was accompanied by an increase of activation in the posterior parietal and occipital cortex. These findings indicate that habitual prospective memory involves retrieval processes guided more strongly by parietal brain structures. In brief, the study demonstrates that episodic and habitual prospective memory tasks recruit different brain areas.

Germanic Mythology in Music: Cultural Memory and Conflict within the Framework of Modern Globalization

The multi-layered enactment of a national past in music has been strongly intertwined with the usage of mythological elements. Having often been compiled as a coherent narrative during the emergence of the European nation-states (like the Finnish Kalevala), the mythological material has often been perceived as a form of historical truth and national justification. This focal role is also apparent in various music genres ranging from folk revival to metal in post-1989 Europe. Within the globalized context, however, local-national interpretations can collide with earlier nationalist appropriations. This complex and sometimes politically conflicting situation becomes particularly evident with groups falling back on symbols and narrations that had previously been employed by Nazi-Germany. While Nazi-Germany had, among others, tried replace the Christmas tradition with elements and songs from Germanic (and other) mythological sources, modern Neo-Nazi music groups often employ central mythological names (like Odin or Tyr) and iconic elements (like Vikings and warriors) in song lyrics and CD cover designs. However, while many covers and lyrics are legally forbidden in Germany, Scandinavian and Baltic groups (like the Faroese Viking metal group Tyr and the Latvian pagan metal band Skyforger) employ similar elements of Norse mythology, which are often combined with traditional material. Discussing selected case studies, this paper highlights central discursive points of colliding historical-national associations and individual interpretations of the mythological elements in musical contexts. How far can the material be disassociated from the earlier historical political usage and instrumentalization? Is this necessary ? And how can the specific global-local conflict points be approached by a theoretical framework ?

Habituation and consolidation of prospective memory over a week: An ERP study

Prospective memory (ProM) is the ability to remember and perform an intention in the future. If a prospective memory task is to be performed only once, it is episodic. If it is repeated, then it becomes habitual. Thus, with repetition, a task changes from episodic to habitual. The goal of this study was to investigate the transition from episodic to habitual prospective memory with event-related potentials (ERP). The ProM task was to respond to a target word which was embedded in an ongoing lexical decision task. 40 ProM trials were administered in each of two sessions that were separated by a week. The results revealed a behavioural consolidation effect with increased ProM performance after one week. The ERP-analyses showed that when the task became more habitual a difference occurred in a time-window between 450-650 ms post-stimulus in an ERP-component. In addition, a covariance analysis revealed that this transition is continued in the second session. These results demonstrate that the transition from episodic to habitual prospective memory is long-lasting and continuous.

Working memory training in children: Effectiveness depends on temperament

Studies revealing transfer effects of working memory (WM) training on non-trained cognitive performance of children hold promising implications for scholastic learning. However, the results of existing training studies are not consistent and provoke debates about the potential and limitations of cognitive enhancement. To examine the influence of individual differences on training outcomes is a promising approach for finding causes for such inconsistencies. In this study, we implemented WM training in an elementary school setting. The aim was to investigate near and far transfer effects on cognitive abilities and academic achievement and to examine the moderating effects of a dispositional and a regulative temperament factor, neuroticism and effortful control. Ninetynine second-graders were randomly assigned to 20 sessions of computer-based adaptiveWMtraining, computer-based reading training, or a no-contact control group. For the WM training group, our analyses reveal near transfer on a visual WM task, far transfer on a vocabulary task as a proxy for crystallized intelligence, and increased academic achievement in reading and math by trend. Considering individual differences in temperament, we found that effortful control predicts larger training mean and gain scores and that there is a moderation effect of both temperament factors on post-training improvement: WM training condition predicted higher post-training gains compared to both control conditions only in children with high effortful control or low neuroticism. Our results suggest that a short but intensive WM training program can enhance cognitive abilities in children, but that sufficient selfregulative abilities and emotional stability are necessary for WM training to be effective.

Acute S100B in serum is associated with cognitive symptoms and memory performance 4 months after paediatric mild traumatic brain injury

OBJECTIVE This study explored whether acute serum marker S100B is related with post-concussive symptoms (PCS) and neuropsychological performance 4 months after paediatric mild traumatic brain injury (mTBI). RESEARCH DESIGN AND METHODS This prospective short-term longitudinal study investigated children (aged 6-16 years) with mTBI (n = 36, 16 males) and children with orthopaedic injuries (OI, n = 27, 18 males) as a control group. S100B in serum was measured during the acute phase and was correlated with parent-rated PCS and neuropsychological performance 4 months after the injury. MAIN OUTCOMES AND RESULTS The results revealed no between-group difference regarding acute S100B serum concentration. In children after mTBI, group-specific significant Spearman correlations were found between S100B and post-acute cognitive PCS (r = 0.54, p = 0.001) as well as S100B and verbal memory performance (r = -0.47, p = 0.006). In children after OI, there were insignificant positive relations between S100B and post-acute somatic PCS. In addition, insignificant positive correlations were found between neuropsychological outcome and S100B in children after OI. CONCLUSIONS S100B was not specific for mild brain injuries and may also be elevated after OI. The group-specific association between S100B and ongoing cognitive PCS in children after mTBI should motivate to examine further the role of S100B as a diagnostic biomarker in paediatric mTBI.