Does handedness influence the strength of phantom limb illusions in the virtual reality box?

Subjects had to judge the size of a tactile stimulus held in the unseen hand, while a visible phantom hand representing that unseen hand held a tactile stimulus of same or different size. No asymmetries in interference effects were found that could be related to hand or handedness. The method lends itself to quantification of virtual reality box illusions and can be used to evaluate the role of experience and sources of variability in the strength of the illusion across subjects.     

Temporal variation in Irish suicide rates

Using Irish suicide data for the period 1990-1998, the independent effects of month and day adjusting for age, gender, and calendar year effects and distinguishing between holiday and working Mondays were assessed. The male suicide rate was significantly higher on working Mondays (+31%) and Saturdays (+14%), and during April, June, and August (+17%), after adjustment for the other variables. In contrast, female suicide rates were higher only in August (+35%) and exhibited no day effect. Teenage men had a greater elevation of risk on Saturdays, Sundays, and both working and holiday Mondays than any other group. The study findings should be taken into account in the planning of specialized health care services and helplines for suicidal people. Furthermore, the findings provide support for Gabennesch's (1988) broken promise theory and the relationship between dysfunctions of the serotonergic system and suicidal behavior.     

The ontogeny of serial-order behavior in humans (Homo sapiens): representation of a list

The authors trained 3-, 4-, 7-, and 10-year-old children and adults (Homo sapiens) on a nonverbal serial-order task to respond to 5 items in a specific order. Knowledge of each item's sequential position was then examined using pairwise and triplet tests. Adults and 7- and 10-year-olds performed at high levels on both tests, whereas 3- and 4-year-olds did not. The latency to respond to the first item of a test pair or triplet was linearly related to that item's position in the training series for the 7- and 10-year-olds and adults, but not for the 3- and 4-year-olds. These data suggest that older children and adults, but not younger children, developed a well-integrated internal representation of the serial list.     

Change in cognitive capabilities in the oldest old: the effects of proximity to death in genetically related individuals over a 6-year period

Change in cognitive abilities was assessed over a 6-year period in a sample of monozygotic and same-sex dizygotic twin pairs (N = 507 individuals), aged 80 and older (mean age = 83.3 years: SD = 3.1). who remained nondemented over the course of the study. Latent growth models (LGMs) show that chronological age and time to death are consistent predictors of decline in measures of memory, reasoning, speed, and verbal abilities. Multivariate LGM analysis resulted in weak and often negative correlations among rates of change between individuals within twin pairs, indicating greater differential change within twin pairs than occurs on average across twin pairs. These findings highlight several challenges for estimating genetic sources of variance in the context of compromised health and mortality-related change.     

The associative memory deficit of older adults: further support using face-name associations

Previous studies have established an associative deficit hypothesis (Naveh-Benjamin, 2000), which attributes part of older adults' deficient episodic memory performance to their difficulty in creating cohesive episodes. In this article, the authors further evaluate this hypothesis, using ecologically relevant materials. Young and old participants studied name-face pairs and were then tested on their recognition memory for the names, faces, and the name-face pairs. The results extend the conditions under which older adults exhibit an associative deficit. They also show that reduced attentional resources are not the sole mediator of this deficit.     

Multiply controlled verbal operants: an analysis and extension to the picture exchange communication system

This paper presents Skinner's (1957) analysis of verbal behavior as a framework for understanding language acquisition in children with autism. We describe Skinner's analysis of pure and impure verbal operants and illustrate how this analysis may be applied to the design of communication training programs. The picture exchange communication system (PECS) is a training program influenced by Skinner's framework. We describe the training sequence associated with PECS and illustrate how this sequence may establish multiply controlled verbal behavior in children with autism. We conclude with an examination of how Skinner's framework may apply to other communication modalities and training strategies.