The Relation of Lifetime Cognitive Activity and Lifetime Access to Resources to Late-life Cognitive Function in Older African Americans

ABSTRACT

Research in older Caucasians has demonstrated that cognitive activity is related to cognitive function in late adulthood. Knowledge of this association is limited in older minority populations. We examined the relation of cognitive activity and access to cognitive resources, with cognitive function in a group of 108 older African Americans. We constructed two scales to measure the frequency of cognitive activity and the presence of resources that promote cognitive activity during early and late life. Both measures had high internal consistency and the cognitive activity scale had adequate temporal stability over a 4-week interval. In analyses that controlled for age and education, more frequent lifetime cognitive activity was related to current cognitive function, but lifetime cognitive resources only approached significance. The results suggest that both measures are psychometrically sound in a minority population and that lifetime cognitive activity may contribute to current cognitive function in African Americans.     

Static items are automatically prioritized in a dynamic environment

Everyday experience provides us with the intuition that dynamic events guide or capture attention—something which has been confirmed in experimental studies. Recently, we showed that there are limitations to the extent to which dynamic items attract attention. In a visual search task where all items, except one, were dynamic, the dynamic items could be ignored and the static item could be efficiently detected. In the present study we investigated whether attention is automatically drawn to the static item. Three visual search experiments, in which the target and the static object were uncorrelated, revealed that the static item was nevertheless prioritized. This result is at odds with some of the current theories on attentional capture, including the “new object” hypothesis. The current study suggests that differences in dynamics, rather than dynamic features per se, determine where attention is allocated.     

Finding a Home of Their Own: Immigrant Housing Experiences in Central Okanagan, British Columbia, and Policy Recommendations for Change

Housing for refugees and immigrants is increasingly an issue in small- and mid-sized cities in the British Columbia interior (Central Okanagan), where the real estate market is one of the most expensive in Canada. This study examines the housing experiences of immigrants in Vernon, Penticton, and Kelowna, using data from focus groups of new immigrants and interviews with key informants. Respondents encountered discrimination based on country of origin, immigration status, and ethnicity or race, as well as housing affordability problems. Participants cope with the latter barrier by either sharing housing to save money or renting a basement. Key informants suggest that government, especially the federal government, must help address the immigrant housing crisis in Central Okanagan by funding affordable housing construction, regulating and cooperating with developers, facilitating dialog between landlords and renters, and supporting community organizations. Municipal governments lack the resources and the constitutional powers to deal with this issue on their own.     

A Comparison of Noncontingent Plus Contingent Reinforcement to Contingent Reinforcement Alone on Students’ Academic Performance

Noncontingent reinforcement (NCR) can be described as time-based or response-independent delivery of stimuli with known reinforcing properties. Previous research has shown NCR to reduce problem behavior in individuals with developmental disabilities and to interfere with the acquisition of more desired alternative behavior. To date, however, little research has examined the effects of NCR on children’s academic performance. The present study examined the effects of NCR on the completion of math computation worksheets by 3 students in an elementary school setting. An ABCB reversal design was used to compare an NCR schedule in combination with contingent reinforcement to contingent reinforcement alone. Results showed that digits correct per session decreased to baseline levels for all 3 students during implementation of the NCR plus contingent reinforcement condition. Implications of these results for the reductive effects of NCR are discussed.     

The mental representation of living and nonliving things: Differential weighting and interactivity of sensorial and non-sensorial features

Warrington and colleagues (Warrington & McCarthy, 1983, 1987; Warrington & Shallice, 1984) claimed that sensorial and functional-associative (FA) features are differentially important in determining the meaning of living things (LT) and nonliving things (NLT). The first aim of the present study was to evaluate this hypothesis through two different access tasks: feature generation (Experiment 1) and cued recall (Experiment 2). The results of both experiments provided consistent empirical support for Warrington and colleagues' assumption. The second aim of the present study was to test a new differential interactivity hypothesis that combines Warrington and colleagues' assumption with the notion of a higher number of intercorrelations and hence of a stronger connectivity between sensorial and non-sensorial features for LTs than for NLTs. This hypothesis was motivated by previous reports of an uncrossed interaction between domain (LTs vs NLTs) and attribute type (sensorial vs FA) in, for example, a feature verification task (Laws, Humber, Ramsey, & McCarthy, 1995): while FA attributes are verified faster than sensorial attributes for NLTs, no difference is observed for LTs. We replicated and generalised this finding using several feature verification tasks on both written words and pictures (Experiment 3), including in conditions aimed at minimising the intervention of priming biases and strategic or mnemonic processes (Experiment 4). The whole set of results suggests that both privileged relations between features and categories, and the differential importance of intercorrelations between features as a function of category, modulate access to semantic features.     

Regression periods in infancy: a case study from Catalonia

Based on Rijt-Plooij and Plooij's (1992) research on emergence of regression periods in the first two years of life, the presence of such periods in a group of 18 babies (10 boys and 8 girls, aged between 3 weeks and 14 months) from a Catalonian population was analyzed. The measurements were a questionnaire filled in by the infants' mothers, a semi-structured weekly tape-recorded interview, and observations in their homes. The procedure and the instruments used in the project follow those proposed by Rijt-Plooij and Plooij. Our results confirm the existence of the regression periods in the first year of children's life. Inter-coder agreement for trained coders was 78.2% and within-coder agreement was 90.1%. In the discussion, the possible meaning and relevance of regression periods in order to understand development from a psychobiological and social framework is commented upon.     

Lesbian, Gay, and Bisexual Identity Scale (LGBIS): construct validation, sensitivity analyses and other psychometric properties

According to Mohr and Fassinger (2006), identity is seen as both self-identification and collective identification with values, beliefs, traits or behaviours and attachments. Their Lesbian, Gay, and Bisexual (LGB) multidimensional identity model accounts for important variables regarding the constitution of identities. This model not only accesses numerous dimensions of the lives of LGB individuals, but is also based on a body of research that recognizes how LGB difficulties are caused by societal intolerance and marginalization (Mohr & Fassinger, 2000). The Lesbian, Gay, and Bisexual Identity Scale (LGBIS; Kendra & Mohr, 2008) constitutes an operationalization of this multidimensional model, and the aim of this article is to present its construct validity by analysing its factor structure using a sample of Portuguese lesbian, gay and bisexual participants. Results from exploratory and confirmatory factor analyses, as well as from factor invariance analysis across sub-samples are presented. In a general way, the factor structure obtained in this study follows the original proposal of Kendra and Mohr's (2008) LGBIS. Moreover, scale sensitivity analyses are presented in order to check for eventual differences in the factor structure and/or factor intercorrelations regarding participant gender and sexual orientation. These results are then discussed in the light of LGB identity models.     

Enhancement of the Post-training Cholinergic Tone Antagonizes the Impairment of Retention Induced by a Nitric Oxide Synthase Inhibitor in Mice

The present experiments examined the role of the central cholinergic system in the memory impairment induced by post-training administration of a nitric oxide synthase (NOS) inhibitor in mice. Male Swiss mice received a one-trial inhibitory avoidance training (0.8 mA, 50 Hz, 1-s footshock) followed immediately by an ip injection of the NOS inhibitor -N^G-nitroarginine methyl ester ( -NAME; 100 mg/kg). Retention (cut-off time, 300 s) was tested 48 h after training. The administration of -NAME results in memory impairment for the inhibitory avoidance task. The effects of -NAME (100 mg/kg, ip) on retention were reversed in a dose-related manner by the centrally acting anticholinesterase physostigmine (35, 70, or 150 μg/kg, sc) administered 30 min after the NOS inhibitor. Further, -NAME (100 mg/kg, ip)-induced memory impairment was completely antagonized by the centrally acting muscarinic cholinergic agonist oxotremorine (OTM; 25, 50, or 100 μg/kg, sc) when given 30 min after -NAME. The peripherally acting anticholinesterase neostigmine (150 μg/kg, sc) did not modify the memory-impairing effects of -NAME. These findings suggest that the memory impairment following post-training administration of a NOS inhibitor is mediated, at least in part, by a reduction of the activity of central muscarinic cholinergic mechanisms and are consistent with our previous view that nitric oxide may be involved in post-training neural processes underlying the storage of newly acquired information.     

Effects of Posttraining Administration of Glucose on Retention of a Habituation Response in Mice: Participation of a Central Cholinergic Mechanism

Male Swiss mice were allowed to explore a novel environment, provided by an open-field activity chamber, for 10 min. The procedure was repeated twice with a 24-h interval. The difference in the exploratory activity between the first (training) and the second (testing) exposures to the chamber was taken as an index of retention of this habituation task. Posttraining intraperitoneal administration of glucose (10–300 mg/kg) enhanced retention in a dose-related manner, although only the dose of 30 mg/kg of glucose produced significant effects. Thus, the dose–response curve adopted an inverted U-shaped form. Glucose (30 mg/kg) given to untrained mice did not modify their exploratory performance when recorded 24 h later. The effects of glucose on retention were time-dependent, suggesting an action on memory storage. The memory-improving actions of glucose were prevented by the simultaneous administration of both the central acting muscarinic cholinergic antagonist atropine (0.5 mg/kg) and by the central acting nicotinic cholinergic antagonist mecamylamine (5 mg/kg). In contrast, neither methylatropine (0.5 mg/kg), a peripherally acting muscarinic receptor blocker, nor hexamethonium (5 mg/kg), a peripherally acting nicotinic receptor blocker, prevented the effects of glucose on retention. Low subeffective doses of glucose (10 mg/kg) and the central anticholinesterase physostigmine (35 μg/kg), but not neostigmine (35 μg/kg), given together, act synergistically and facilitated retention. We suggest that glucose modulates memory storage of one form of learning elicited by stimuli repeatedly presented without reinforcement, probably through an enhancement of brain acetylcholine synthesis and/or its release.