Effects of lipopolysaccharide on consolidation of partial learning in the Y-maze

Research on consolidation of long-term memory suggests that acute immune system activation induced by endotoxin lipopolysaccharide (LPS) may disrupt consolidation of newly acquired learning. Adult male Sprague-Dawley rats were trained to perform a simple Y-maze task and were immediately afterwards administered LPS (15 μg/kg) or saline. After a seven-day interval, subjects were returned to the Y-maze and were retrained to criterion. It was found that subjects treated with saline required significantly fewer trials to relearn the task relative to the LPS group and a no-partial-learning control group, which themselves did not differ. These results are most readily explained in terms of a disruptive effect of acute immune system activation on consolidation of newly induced acquired memories.     

How does running memory span work?

In running memory span, a list ends unpredictably, and the last few items are to be recalled. This task is of increasing importance in recent research. We argue that there are two very different strategies for performing running span tasks: a low-effort strategy in which items are passively held until the list ends, when retrieval into a capacity-limited store takes place; and a higher-effort strategy in which working memory is continually updated using rehearsal processes during the list presentation. In two experiments, we examine the roles of these two strategies and the consequences of two types of interference.     

New subscales for an anchored version of the Brief Psychiatric Rating Scale: construction, reliability, and validity in acute psychiatric admissions

Attending psychiatrists completed an anchored version of the 18-item Brief Psychiatric Rating Scale (BPRS-A) based on admission and evaluation information on a total of 2,921 adult patients treated at 1 public sector acute psychiatric teaching hospital. Exploratory factor analysis was applied to a 6-month sample to construct 4 nonoverlapping subscales: Resistance, Positive Symptoms, Negative Symptoms, and Psychological Discomfort. Confirmatory factor analysis compared these new subscales to 3 other published subscale models using a second 6-month sample. Internal consistency, rater influence, and interrater agreement were estimated in separate studies. Discriminant validity was explored by comparison of diagnosis-based samples. Application of the BPRS-A as a debriefing instrument in the study of symptomatic change and the multiple challenges inherent in psychometric study of such a rating scale in realistic hospital practice are discussed.     

Behavior problems and peer rejection in preschool boys and girls

The authors tested the hypothesis that deviant behaviors within a preschool peer group would be linked with peer rejection, irrespective of child gender. Seventy-six children, aged 3 to 5 years, participated. Teachers rated children's behavior on the Child Adaptive Behavior Inventory, and children provided sociometric ratings. For a subsample of children (n = 47), observers coded aggressive, noncompliant, and withdrawn behavior using a time-sampling system. For both boys and girls, noncompliance, hyperactivity, and social withdrawal were associated with peer rejection; overt aggression was associated with peer rejection for boys, but not for girls. Analysis revealed that approximately half of the variance in sociometric and teacher ratings of peer rejection was accounted for by aggression and social withdrawal for both boys and girls. The results suggest that the association between behavior problems and peer rejection emerges at a very early age.     

The epidemiology of the epilepsies in children

The epilepsies are a heterogeneous collection of neurological conditions and syndromes characterized by recurrent, unprovoked, paroxysmal seizure activity. There are several types of epileptic seizures and syndromes that are unique to children, including infantile spasms, Lennox-Gastaut syndrome and absence seizures. Febrile seizures and neonatal seizures, while not epilepsy, are relatively common types of seizures in infants and children and are likely markers of risk of later epilepsy. Thus, it is important to consider the epidemiological features of the epilepsies as they occur specifically in infants and children. The purpose of this review is to summarize what is currently known about the epidemiology of the childhood epilepsies and to identify promising areas for further population-based studies. The epilepsies are an important cause of neurological morbidity in children. The average annual rate of new cases (incidence) of epilepsy is approximately 5-7 cases per 10,000 children from birth to age 15 years, and in any given year, about 5 of every 1,000 children will have epilepsy. There is evidence that the incidence of the epilepsies in some populations of children may be decreasing over time, and this possibility merits further investigation. Factors that are known to increase risk of the epilepsies in children include congenital malformations of the central nervous system (CNS), moderate or severe head trauma, CNS infections, certain inherited metabolic conditions, and genetic factors. However, these account for only 25% to 45% of cases, and thus, the etiology of most cases of the epilepsies remains obscure. The paucity of well-controlled etiological studies is due largely to formidable methodological problems in conducting epidemiological studies of the epilepsies. The prognosis for seizure control is generally good, although children with remote symptomatic seizures and those with additional neurological disabilities do less well.     

Persistence of memory for ignored lists of digits: areas of developmental constancy and change

Contrary to the common belief that sensory memory remains unchanged across development in childhood, there have been several previous reports suggesting that the persistence of sensory memory, at least for sounds, increases with age in childhood. Because those previous studies all used isolated sounds as stimuli, it is not yet clear how this developmental difference influences the recall of sound series. The present study adapts the procedure of J. S. Saults and N. Cowan (1996), who studied memory for attended and ignored spoken words, to examine here the recall of attended and ignored lists of digit. A developmental increase in the persistence of memory was obtained only for the final item in an ignored list, which is the item for which sensory memory is thought to be the most vivid at short retention intervals.     

Dreams,Morality and the Waking World

Is it ever wrong to cheat in a dream? It has been argued that the conjunction of reasonable claims about dreams with Evaluational Internalism (the view that moral evaluation is determined by factors ‘internal’ to agency, such as intentions) entails a positive answer. This implausible result seemingly provides reason to favour an alternative theory of moral evaluation. I here argue that a wide range of Evaluational Externalist views (which base moral evaluation on factors ‘external’ to agency, such as harms produced) are similarly committed to morality in dreams. I end by identifying implications for theorising about dreams and morality.     

A generalized signal detection model to predict rational variation in base rate use

The predominant models of rational behavior currently used to analyze a large class of experiments imply that subjects neglect or place insufficient weight on base rates when making probabilistic judgments. We argue that the evidence is inadequate for this conclusion because the models make needlessly restrictive assumptions about how base rates should be used. The restrictive assumptions stem from a misuse of Bayes' rule that ignores specific aspects of how the proportions arose. We develop a model of rational behavior that generalizes signal detection theory to reflect the environment subjects routinely face and we reexamine the relevant experimental literature. Variation observed in subjects' responses to base rate information is explained by the present rational model more fully than by extant models.     

Face Recognition in Poor-Quality Video; Evidence From Security Surveillance

Security surveillance systems often produce poor-quality video, and this may be problematic in gathering forensic evidence. We examined the ability of subjects to identify target people captured by a commercially available video security device. In Experiment 1, subjects personally familiar with the targets performed very well at identifying them, but subjects unfamiliar with the targets performed very poorly. Police officers with experience in forensic identification performed as poorly as other subjects unfamiliar with the targets. In Experiment 2, we asked how familiar subjects can perform so well. Using the same video device, we edited clips to obscure the head, body, or gait of the targets. Obscuring body or gait produced a small decrement in recognition performance. Obscuring the targets' heads had a dramatic effect on subjects' ability to recognize the targets. These results imply that subjects recognized the targets' faces, even in these poor-quality images.     

Think before you speak: pauses, memory search, and trace redintegration processes in verbal memory span

Immediate memory span and speed of memory search were assessed for words and nonwords of short and long spoken duration. Memory span was substantially greater for words than for nonwords and for short than for long items, though speed of memory search was unaffected by either length or lexicality. An analysis of the temporal pattern of responses in the memory span task indicated that inter-item pauses were longer between nonwords than words but that these pause durations were unaffected by item length. A model of verbal short-term memory span is described in which trace selection from a short-term store and the redintegration (restoration) of degraded phonological traces both occur in the pauses between saying successive items. Both trace selection and trace redintegration appear to play important roles in accounting for individual differences in memory span.