Effects of stress hormones on traumatic memory formation and the development of posttraumatic stress disorder in critically ill patients

A majority of patients after intensive care treatment report traumatic memories from their stay in the intensive care unit (ICU). Traumatic memories can be associated with the development of posttraumatic stress disorder (PTSD) in a subpopulation of these patients. In contrast to other patient populations at risk for PTSD, patients in the ICU often receive exogenously administered stress hormones like epinephrine, norepinephrine, or cortisol for medical reasons and are extensively monitored. ICU patients therefore represent a suitable population for studying the relationship between stress hormones, traumatic memories, and the development of PTSD. Studies in long-term survivors of ICU treatment demonstrated a clear and vivid recall of different categories of traumatic memory such as nightmares, anxiety, respiratory distress, or pain with little or no recall of factual events. The number of categories of traumatic memory recalled increased with the total administered dosages of stress hormones (both catecholamines and cortisol), and the evaluation of these categories at different time points after discharge from the ICU showed better memory consolidation with higher dosages of stress hormones administered. However, the administration of stress doses of cortisol to critically ill patients resulted in more complex findings as it caused a significant reduction in PTSD symptoms measured after recovery. This effect can possibly be explained by a differential influence of cortisol on memory. Increased serum cortisol levels not only result in consolidation of emotional memory but are also known to cause a temporary impairment in memory retrieval which appears to be independent of glucocorticoid effects on memory formation. Disrupting retrieval mechanisms with glucocorticoids during critical illness may therefore act protectively against the development of PTSD by preventing recall of traumatic memories. Our findings indicate that stress hormones influence the development of PTSD through complex and simultaneous interactions on memory formation and retrieval. Our studies also demonstrate that animal models of aversive learning are useful in analyzing and predicting clinical findings in critically ill humans.     

Adaptive motor behavior of cerebellar patients during exposure to unfamiliar external forces

The authors investigated adaptation of goal-directed forearm movements to an unknown external viscous force assisting forearm flexion in 6 patients with cerebellar dysfunction and in 6 control participants. Motor performance was generally degraded in cerebellar patients and was markedly reduced under the force condition in both groups. However, patients and controls were able to adapt to the novel force within 8 trials. Only the healthy controls were able to improve motor performance when readapting to a null-force condition. The results indicate that cerebellar patients' motor control system has imprecise estimations of actual limb dynamics at its disposal. Force adaptation may have been preserved because single-joint movements were performed, whereas the negative viscous force alone and no interaction forces had to be compensated.     

Linguistic stress, within-word position, and grammatical class in relation to early childhood stuttering

The purpose of the present study was to investigate whether the link that has been established between stuttering and linguistic stress in adolescents and adults (the so-called stress effect) can also be observed in childhood stuttering. To account for confounding variables, both within-word position and grammatical class were measured, because these factors covary with linguistic stress. Speech samples of 22 preschool children (mean time of 9 months since onset of stuttering) were analyzed. The relative stress of each syllable was rated and syllables were categorized into long and short stressed, unstressed, and intermediately stressed syllables. Results showed that 97.8% of stuttering events occurred on first syllables of words and 76.5% on the first sound of syllables, that means a clear word-initial effect. Stuttering frequency on first syllables of function words was 16.9% and significantly higher than the frequency of stuttered first syllables of content words (11.5%). In function words short stressed syllables and intermediately stressed syllables were stuttered more often than unstressed syllables. The analysis for individual disfluency types revealed that, for function words, stuttering on short stressed syllables was associated with prolongations and syllable repetitions. However, in intermediately stressed syllables stuttering coincided most often with one-syllable word repetitions. This differentiation of the stress effect may suggest different causal mechanisms underlying these disfluency types. Educational objectives: The reader will learn about and be able to: (1) describe how within-word position, grammatical class, and linguistic stress effect stuttering frequency in preschool children who stutter; (2) explain how the occurrence of individual disfluency types depends on linguistic stress; (3) discuss how patterns of adults and preschool children who stutter differ in regard to these aspects.     

Constructing sacred space under the forces of the market: A study of an ‘upper-floor’ Protestant church in Hong Kong

In Hong Kong, over half of the Protestant churches are located in the upper-floor units in commercial and residential buildings. Because of their physical locations, these churches are sometimes dubbed ‘upper-floor churches’. Unlike those that occupy stand-alone religious buildings or dwell in church-run schools and social service centres, these are often invisible in the landscapes of the city. Through analysis of a case study, this paper aims to explore the spatial practices that a Protestant community has adopted in acquiring, representing, and ritualising a business unit in a residential high-rise for building up their church. Our analysis of the case study shows that in a metropolis like contemporary Hong Kong, the construction of sacred space is full of tensions between utilitarian calculations and concerns of human relations and religious values. While the congregation had been very creative in transforming a commercial unit into a religious site, it did not show much awareness of the oppressive powers of the capitalist market and had a strong tendency to represent its spatial practices as commodities for consumption.