Assessment of age-related changes in inhibition and binding using eye movement monitoring

Age-related memory deficits may result from attending to too much information (inhibition deficit) and/or storing too little information (binding deficit). The present study evaluated the inhibition and binding accounts by exploiting a situation in which deficits of inhibition should benefit relational memory binding. Older adults directed more viewing toward abrupt onsets in scenes compared with younger adults under instructions to ignore any such onsets, providing evidence for age-related inhibitory deficits, which were ameliorated with additional practice. Subsequently, objects that served as abrupt onsets underwent changes in their spatial relations. Despite successful inhibition of the onsets, eye movements of younger adults were attracted to manipulated objects. In contrast, the eye movements of older adults, who directed more viewing to the late onsets compared with younger adults, were not attracted toward manipulated regions. Similar differences between younger and older adults in viewing of manipulated regions were observed under free viewing conditions. These findings provide evidence for concurrent inhibition and binding deficits in older adults and demonstrate that age-related declines in inhibitory processing do not lead to enhanced relational memory for extraneous information.     

Dissemination of psychoactive substance information by innovative drug users.

Internet-based drug information may be relayed by innovative drug users, a group of individuals who use the web to learn about a new drug, experiment with that substance, and then disseminate their knowledge and experiences to others. We investigated the mechanisms adopted by innovative drug-using adolescents to distribute Internet drug information and experiences to peers, the size and geographic distribution of the receiving group, and the age at which innovative drug users began to disseminate drug information. Method: Cross-sectional survey of adolescents recruited by a respondent-driven sampling method. Of 18 innovative drug users, 17 reported using instant messaging (IM) to disseminate drug information and experiences to peers. The average age at which respondents adopted IM for this purpose was 16 years. Fifteen of 17 described using a distribution list with as many as 200 individuals who received only drug information. Ten respondents instant messaged drug information to online peers greater than 250 miles distant; nine respondents attached links to online drug resources (including www.erowid.org). This study has identified that IM plays an important role in the dissemination of Internet-based drug information by individual innovative drug users into larger social networks. Pediatricians should consider assessing IM use in drug abuse evaluations and recommending that parents of children with drug abuse problems should consider suspending IM services as a means of truncating the delivery of reinforcing drug information.     

RESPONSE ALLOCATION IN CONCURRENT CHAINS WHEN TERMINAL‐LINK DELAYS FOLLOW AN ASCENDING AND DESCENDING SERIES

Eight pigeons were trained in a concurrent‐chains procedure in which the terminal‐link immediacy ratio followed an ascending or descending series. Across sessions, one terminal‐link delay changed from 2 s to 32 s to 2 s or from 32 s to 2 s to 32 s, while the other was always 8 s. For all pigeons, response allocation tracked changes in delay and was biased towards the 8‐s alternative on the descending series, indicating a hysteresis effect, and was more sensitive to changes in the terminal‐link delay ratio for relatively long (> 8 s) than short (< 8 s) delays. Both the hysteresis and effect of delay duration were predicted by an extended version of Grace and McLean's (2006) decision model. The extended decision model provided an overall better account of the results than a simple linear‐operator model (Grace, 2002), and holds promise for an integrated account of choice in concurrent chains for both acquisition and steady‐state conditions.     

A decision model for steady-state choice in concurrent chains

Grace and McLean (2006) proposed a decision model for acquisition of choice in concurrent chains which assumes that after reinforcement in a terminal link, subjects make a discrimination whether the preceding reinforcer delay was short or long relative to a criterion. Their model was subsequently extended by Christensen and Grace (2008, 2009a, 2009b) to include effects of initial- and terminal-link duration on choice. We show that an expression for steady-state responding can be derived from the decision model, which enables a model for choice that provides an account of archival data that is equal or superior to the contextual choice model (Grace, 1994) and hyperbolic value-added model (Mazur, 2001) in terms of goodness of fit, parsimony, and parameter invariance. The success of the steady-state decision model validates the strategy of understanding acquisition phenomena as a bridge toward explaining choice at the molar level.     

Academic Stressors and Anxiety in Children: The Role of Paternal Support

We examined the role of paternal support in the relation between academic stress and the mental health of primary school children in Hong Kong. The participants of this cross-sectional study were 1,171 fifth and sixth graders. The results indicated that academic stress was a risk factor that heightened student anxiety levels and that parental emotional support was a protective factor that contributed to better mental health among children. However, paternal informational support delivered to children during times of high academic stress appeared to heighten student anxiety levels. The practical implications of the findings on parent education are discussed.     

Non‐instrumental voice and extra‐role behaviour

The instrumental power associated with voicing opinions to an authority was manipulated to observe the effects upon subsequent discretionary, extra‐role behaviours. In two experiments, the provision of non‐instrumental voice increased extra‐role behaviours above a no voice condition. Experiment 2 also showed that this relationship was mediated by procedural‐justice perceptions, but not respect from, or social identification with, the group. The implications of these data for current theory, as well as the possible moderating role of social identification, are discussed. Copyright © 2005 John Wiley & Sons, Ltd.     

Multiple Risk Factors for Frequent and Problem Gambling: Individual, Social, and Ecological

We analyzed data for a national U.S. telephone survey. Most likely to have gambled in the past year were those whose friends and families looked favorably on gambling, Catholics, young adults, and those who live close to a lottery outlet. Most likely to have gambled frequently in the past year were those whose friends look favorably on gambling and those who live close to a lottery outlet. Most likely to be problem gamblers were Blacks, those who smoke or who are alcohol dependent, and those who live in disadvantaged neighborhoods. The decision to gamble is influenced by social milieu and values, while risk for problem gambling is influenced by proneness to problem behaviors and by disadvantaged status. Availability of gambling influences all gambling involvement.