Working memory in the oldest-old: evidence from output serial position curves

In the present study, we examined adult age differences in short-term and working memory performance in middle-aged (45–64 years), young–old (65–74 years), old–old (75–89 years), and oldest–old adults (90 years and over) in the Louisiana Healthy Aging Study. Previous research suggests that measures of working memory are more sensitive to age effects than are simple tests of short-term memory Bopp and Verhaeghen (Journal of Gerontology: Psychological Sciences 60:223–233, 2005), Myerson, Emery, White, and Hale, (Aging, Neuropsychology, and Cognition 10:20–27, 2003). To test this hypothesis, we examined output serial position curves of recall data from three span tasks: forward and backward digit span and size judgment span. Participants’ recall patterns in the size judgment span task revealed that the two oldest groups of adults showed the largest decreases in recall performance across output serial positions, but did not differ significantly from each other. Correlation analyses indicated the strongest negative correlation with age occurred with the size judgment span task. Implications of these findings for understanding strategic processing abilities in late life are discussed.     

Infant color preference for red is not selectively context specific

It has been proposed that human infants, like nonhuman primates, respond favorably to red in hospitable contexts, yet unfavorably in hostile contexts (Maier, Barchfeld, Elliot, & Pekrun, 2009). Here, we replicate and extend the study (Maier et al., 2009) whose findings have been used to support this hypothesis. As in Maier et al., 1-year-old infants were shown a photograph of a happy or angry face before pairs of colors were presented, yet in the current study, the set of stimuli crucially included two colors that are typically preferred by infants (red and blue). The percentage of times that infants looked first at the colors was analyzed for the two emotional "contexts." Following the happy face, infants looked first at red and blue equally, but significantly more than green. Following the angry face, the pattern of looking preference was the same as following the happy face, but the variation across the three colors was reduced. Contrary to Maier et al.'s hypothesis, there was no evidence that infants are selectively averse to red in angry contexts: following the angry face, "preference" for both red and blue was reduced, but was not significantly below chance. We therefore suggest an alternative account to Maier et al.'s evolutionary hypothesis, which argues that an angry face merely removes infant color preference, potentially due to the perceptual characteristics of the angry face disrupting infants' encoding of color. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Item analysis and differential item functioning of a brief conduct problem screen

Research has shown that boys display higher levels of childhood conduct problems than girls, and Black children display higher levels than White children, but few studies have tested for scalar equivalence of conduct problems across gender and race. The authors conducted a 2-parameter item response theory (IRT) model to examine item characteristics of the Authority Acceptance scale from the Teacher Observation of Classroom Adaptation-Revised (AA-TOCA-R; L. Larsson-Werthamer, S. G. Kellam, & L. Wheeler, 1991) in 8,820 kindergarten children and estimated the degree of differential item functioning (DIF) by gender and race/urban status. The mean level of latent conduct problems was best represented by behaviors such as being stubborn, breaking rules, and being disobedient, whereas breaking things and taking others' property best represented the construct at one standard deviation above the mean. DIF by gender was detected, such that at equivalent levels of latent conduct problems, males received more endorsements of overt behaviors from teachers, whereas females received more endorsements of nonphysical behaviors. Moreover, overt behaviors were better discriminators of latent conduct problems for males, and nonphysical behaviors were better discriminators of latent conduct problems for females. Differences across race/urban status were not found to be conceptually meaningful. The authors' analyses also suggest that the item scaling of the AA-TOCA-R may be best represented by 5e categories instead of 6. These findings provide support for the use of IRT modeling to examine item characteristics of conduct problem scales and DIF to test for scalar equivalence across diverse subpopulations.     

Environmental enrichment protects against the effects of chronic stress on cognitive and morphological measures of hippocampal integrity

Chronic stress has detrimental effects on hippocampal integrity, while environmental enrichment (EE) has beneficial effects when initiated early in development. In this study, we investigated whether EE initiated in adulthood would mitigate chronic stress effects on cognitive function and hippocampal neuronal architecture, when EE started one week before chronic stress began, or two weeks after chronic stress onset. Adult male Sprague Dawley rats were chronically restrained (6h/d) or assigned as non-stressed controls and subdivided into EE or non-EE housing. After restraint ended, rats were tested on a radial arm water maze (RAWM) for 2-d to assess spatial learning and memory. The first study showed that when EE began prior to 3-weeks of chronic stress, EE attenuated chronic stress-induced impairments in acquisition, which corresponded with the prevention of chronic stress-induced reductions in CA3 apical dendritic length. A second study showed that when EE began 2-weeks after the onset of a 5-week stress regimen, EE blocked chronic stress-induced impairments in acquisition and retention at 1-h and 24-h delays. RAWM performance corresponded with CA3 apical dendritic complexity. Moreover, rats in EE housing (control or stress) exhibited similar corticosterone profiles across weeks, which differed from the muted corticosterone response to restraint by the chronically stressed pair-housed rats. These data support the interpretation that chronic stress and EE may act on similar mechanisms within the hippocampus, and that manipulation of these factors may yield new directions for optimizing brain integrity and resilience under chronic stress or stress related neuropsychological disorders in the adult.     

Accuracy of Clinician Predictions of Future Self‐Harm: A Systematic Review and Meta‐Analysis of Predictive Studies

Assessment of a patient after hospital‐treated self‐harm or psychiatric hospitalization often includes a risk assessment, resulting in a classification of high risk versus low risk for a future episode of self‐harm. Through systematic review and a series of meta‐analyses looking at unassisted clinician risk classification (eight studies; N = 22,499), we found pooled estimates for sensitivity 0.31 (95% CI: 0.18–0.50), specificity 0.85 (0.75–0.92), positive predictive value 0.22 (0.21–0.23), and negative predictive value 0.89 (0.86–0.92). Clinician classification was too inaccurate to be clinically useful. After‐care should therefore be allocated on the basis of a needs rather than risk assessment.     

An Empirical Test of the Three‐Step Theory of Suicide in U.K. University Students

The purpose of this study was to further our understanding of how individuals move down the pathway from first thinking about suicide to ultimately attempting to take their own lives by empirically testing the Three‐Step Theory (3ST) in a sample of university students (n = 665). Results largely support the theory's central propositions. First, an interactive model of pain and hopelessness accounted for substantial variance in suicidal desire. This result replicated in both men and women, and across age groups (i.e., below 35 and at or above 35). Also, as predicted, connectedness was protective against ideation in those high on both pain and hopelessness. However, contrary to our prediction, connectedness was similarly protective among everyone else. Finally, suicide capacity predicted suicide attempt history over and above current and lifetime suicide ideation. These findings provide further support to the 3ST.