Effects of prone and supine positions on sleep state and stress responses in preterm infants

Aim

The purpose of the study is to assess the influence of prone or supine position on sleep states and on withdrawal and approach reactions of preterm infants.

Methods

Thirty-two preterm infants from Meir Medical Center, Israel, mean post menstrual age 30.37 ± 2.57, mean birth weight 1250 g ± 313.86, participated in the study. Infants were studied during 48 h. Positions (prone and supine) were alternated every 3-4 h after feedings. Sleep states were assessed by Actigraph measurement and by two daily 30-min Naturalistic Observations of Newborn Behavior (NONB) to confirm sleep states and for recording the behavioral reactions (approach and withdrawal).

Results

In the prone position there were more approach reactions as compared to withdrawal reactions (p < .001) while in the supine position, the approach and withdrawal reactions were comparable. In the prone position more sleep patterns (deep sleep, light sleep, drowsy) were observed as opposed to more awake patterns (quiet awake, active awake and agitated fussy) that were seen in the supine position.

Conclusions

Clinical implications encourage placing the preterm infant in the prone position while in the NICU. This enables important achievements such as longer periods of quality sleep, and production of adaptive self-regulatory reactions.     

Behavioral and self‐reported aggression as a function of domain‐specific self‐esteem

On the basis of a domain‐specific theory of self‐esteem, it was hypothesized that functionally distinct domains of self‐esteem would predict aggression differentially. Participants completed self‐report measures of self‐perceived superiority, mate value, social inclusion, and global self‐esteem, as well as of aggression. Self‐assessed mate value emerged as a reliable, positive predictor, and social inclusion as a reliable inverse predictor, of self‐reported hostility and aggression. In a subsequent laboratory experiment, in which participants had an opportunity to aggress against the source of positive or negative feedback about a personal essay that they had written, mate value again predicted increased aggression, whereas global self‐esteem predicted decreased aggression. These main effects were moderated by the feedback manipulation, such that their respective simple effects were only present among participants that received negative feedback. Aggr. Behav. 00:1–11, 2005. © 2005 Wiley‐Liss, Inc.     

The role of the executive system in visuo-spatial memory functioning

Participants were presented with a spatial sequence in which between 4 and 10 cells were highlighted. On each trial list length was unknown to the participant who was required to serially recall the last four cells. Processing of longer lists is assumed to call upon the executive system, which is thought to be involved in updating the contents of the short-term visuo-spatial store. Study 1 revealed that loading the executive system with concurrent random letter generation impaired performance on the spatial task especially recall of the early serial positions. However, contrary to expectation the degree of impairment was no greater on the longer lists, where it had been assumed that updating would be occurring. Study 2 confirmed this finding and demonstrated that relative to sequences of known length, under conditions of uncertainty when the list length was unknown, spatial recall was impaired even on short sequences. The present results support the growing consensus, which is suggestive of closer links between visuo-spatial and executive processes. However, it remains unclear whether or not updating is actually occurring on the longer sequences, and if it is, what specific executive processes are involved.     

Neglected Factors Bearing on Reaction Time in Language Production

The input to phonological reasoning are alternations, that is, variations in the pronunciation of related words, such as in electri[k] - electri[s]-ity. But phonologists cannot agree what counts as a relevant alternation: the issue is highly contentious despite a research record of over 50 years. We believe that the experimental setup presented may contribute to this debate based on a kind of evidence that was not brought to bear to date. Our experiment was thus designed to distinguish between alternations where phonological computation plays no role, and those where it has contributed to language production. The design manipulates two factors that to date have not been considered in experimental studies of language production: linguistic complexity and alternation specificity. The former is understood as extra processing demands issued by two types of linguistic activity, morphosyntactic and phonological. Our results show that reaction time latencies are longer when participants are burdened with both morphosyntactic and phonological tasks than when they carry out just a morphosyntactic task, and they are still shorter in absence of both types of demands. These results allowed us to address alternation specificity, that is, the fact that different alternations (within a language or across languages) may be driven by different production routines (an idea that is consensual among linguists but underdeveloped in the psycholinguistic literature). Our study shows that four different alternations in French produce alternation-specific signatures in reaction time latencies. These findings may thus redound to the advantage of psycholinguistic studies by identifying two new factors, as well as produce results that speak to the linguistic quarrels.     

汉字、数字和符号的身份信息和位置信息加工比较——中文阅读的特别机制

汉字、数字和符号的身份信息和位置信息加工存在怎样的差异,以及在不同呈现方式下是否表现不同,现在仍不清楚。本研究采用9选1部分报告范式,通过字符串水平呈现和竖直呈现两个实验来对这一问题进行探究。结果发现,水平呈现对于不同类型字符的身份信息和位置信息加工都更有优势。数字在不同呈现方式下都表现出绝对优势,且水平呈现时存在首位置优势,表明“改变的接受域”理论对于汉语语系地区数字系列位置效应解释的可能性。同时,汉字与符号更为相似,但水平呈现时汉字位置信息加工更好,且表现出更为明显的注视点左侧(包括注视点)优势,这可能是中文阅读的特别机制。     

Investigating whether maternal memory specificity is indirectly associated with child memory specificity through maternal reminiscing

Maternal reminiscing and remembering has a profound influence on the development of children’s autobiographical remembering skills. The current study investigated the relationships between maternal memory specificity, maternal reminiscing and child memory specificity. Participants consisted of 40 mother–child dyads. Children’s age ranged between 3.5 and 6 years. Mothers and children participated in individual assessments of autobiographical memory specificity. Dyads participated in a joint reminiscing task about three past emotional (happy, sad, stressful) events. A positive moderate association was found between maternal autobiographical memory specificity and child autobiographical memory specificity. Maternal autobiographical memory specificity was significantly correlated with mothers’ focus on the task, involvement and reciprocity, resolution of negative feelings, and structuring of narratives in the mother–child reminiscing task. Moderate positive associations were found between maternal focus and structuring and child memory specificity. There was no evidence to suggest maternal elaborative reminiscing style was significantly positively correlated with mother or child memory specificity. Finally, there was support for an indirect pathway between maternal memory specificity and child memory specificity through quality of support and guidance provided by the mother in maternal reminiscing. Theoretical and clinical implications are considered.     

Influence of memory theme and posttraumatic stress disorder on memory specificity in British and Iranian trauma survivors

This study investigated the influence of culture, memory theme and posttraumatic stress disorder (PTSD) on autobiographical memory specificity in Iranian and British trauma survivors. Participants completed the Autobiographical Memory Test and PTSD Diagnostic Scale. The results indicated that the British group provided significantly more personal-themed memories than the Iranian group, while the Iranian group provided significantly more social-themed memories than the British group. The British group also provided a significantly greater proportion of specific personal-themed and social-themed memories than the Iranian group. Overall, in both cultural groups memory specificity was found to be significantly correlated with PTSD symptoms. These findings provide further evidence that regardless of memory theme, specificity of autobiographical memories function to differentiate the self from others and reaffirm the independent self. They also further highlight that pan-culturally an overgeneral retrieval style may be employed by those with PTSD symptoms.     

Arm position influences the activation patterns of trunk muscles during trunk range-of-motion movements

To understand the activation patterns of the trunk musculature, it is also important to consider the implications of adjacent structures such as the upper limbs, and the muscles that act to move the arms. This study investigated the effects of arm positions on the activation patterns and co-activation of the trunk musculature and muscles that move the arm during trunk range-of-motion movements (maximum trunk axial twist, flexion, and lateral bend). Fifteen males and fifteen females, asymptomatic for low back pain, performed maximum trunk range-of-motion movements, with three arm positions for axial twist (loose, crossed, abducted) and two positions for flexion and lateral bend (loose, crossed). Electromyographical data were collected for eight muscles bilaterally, and activation signals were cross-correlated between trunk muscles and the muscles that move the arms (upper trapezius, latissimus dorsi). Results revealed consistently greater muscle co-activation (higher cross-correlation coefficients) between the trunk muscles and upper trapezius for the abducted arm position during maximum trunk axial twist, while results for the latissimus dorsi-trunk pairings were more dependent on the specific trunk muscles (either abdominal or back) and latissimus dorsi muscle (either right or left side), as well as the range-of-motion movement. The findings of this study contribute to the understanding of interactions between the upper limbs and trunk, and highlight the influence of arm positions on the trunk musculature. In addition, the comparison of the present results to those of individuals with back or shoulder conditions may ultimately aid in elucidating underlying mechanisms or contributing factors to those conditions.     

The importance of understanding: Model space moderates goal specificity effects

The three-space theory of problem solving predicts that the quality of a learner's model and the goal specificity of a task interact on knowledge acquisition. In Experiment 1 participants used a computer simulation of a lever system to learn about torques. They either had to test hypotheses (nonspecific goal), or to produce given values for variables (specific goal). In the good- but not in the poor-model condition they saw torque depicted as an area. Results revealed the predicted interaction. A nonspecific goal only resulted in better learning when a good model of torques was provided. In Experiment 2 participants learned to manipulate the inputs of a system to control its outputs. A nonspecific goal to explore the system helped performance when compared to a specific goal to reach certain values when participants were given a good model, but not when given a poor model that suggested the wrong hypothesis space. Our findings support the three-space theory. They emphasize the importance of understanding for problem solving and stress the need to study underlying processes.