Training effects on dual-task performance: are there age-related differences in plasticity of attentional control?

A number of studies have suggested that attentional control skills required to perform 2 tasks concurrently become impaired with age (A. A. Hartley, 1992; J. M. McDowd & R. J. Shaw, 2000). A. A. Hartley (2001) recently observed that the age-related differences in dual-task performance were larger when the 2 tasks required similar motor responses. The present study examined the extent to which age-related deficits in dual-task performance or time sharing--in particular, dual-task performance of 2 discrimination tasks with similar motor requirements--can be moderated by training. The results indicate that, even when the 2 tasks required similar motor responses, both older and younger adults could learn to perform the tasks faster and more accurately. Moreover, the improvement in performance generalized to new task combinations involving new stimuli. Therefore, it appears that training can substantially improve dual-task processing skills in older adults.     

Mea culpa: predicting stock prices from organizational attributions

People's causal attributions for events in their lives have been shown to relate to individual and interpersonal outcomes. Groups and organizations also make causal attributions, and this article examines whether their publicly communicated attributions predict organizational-level outcomes. By content analyzing attributions contained in corporate annual reports from 14 companies during a 21-year period, the authors found that organizations that made "self disserving" attributions- internal and controllable attributions for negative events-had higher stock prices 1 year later. The authors argue that claiming personal responsibility for negative events made the organizations appear more in control, leading to more positive impressions.     

Amodal completion in visual search: preemption or context effects?

In a previous study, search for a notched-disk target abutting a square among complete-disk nontargets and squares was inefficient in 250-ms exposures, but relatively efficient in 100-ms exposures. This finding was interpreted as evidence that amodal completion proceeds through a mosaic and then a completion stage, with the latter preempting the former. We used the same target but changed its context: Nontargets were instead notched disks near squares. Task set was also different: Participants searched for a complete disk. Contrary to the prediction of the preemption model, search was efficient in the 100-ms condition and inefficient in the 250-ms condition. We propose that in both the present and the previous studies, the target was ambiguous, and task set and context affected how it was perceived. In both experiments, set effects were evident for 100-ms exposures; context effects were evident for 250-ms exposures.     

Nicotinic cholinergic synaptic mechanisms in the ventral tegmental area contribute to nicotine addiction

Tobacco use is a major health problem that is estimated to cause 4 million deaths a year worldwide. Nicotine is the main addictive component of tobacco. It acts as an agonist to activate and desensitize nicotinic acetylcholine receptors (nAChRs). A component of nicotine's addictive power is attributable to actions on the mesolimbic dopaminergic system, which serves a fundamental role in the acquisition of behaviors that are inappropriately reinforced by addictive drugs. Here we show that nicotine, in the same concentration and time ranges as obtained from tobacco, has three main actions that regulate the activity of midbrain dopamine (DA) neurons. Nicotine first activates and then desensitizes nAChRs on the DA neurons. This process directly excites the DA neurons for a short period of time before the nAChRs desensitize. Nicotine also enhances glutamatergic excitation and decreases GABAergic inhibition onto DA neurons. These events increase the probability for synaptic plasticity, such as long-term potentiation. The short-lived direct excitation of the DA neurons coupled with the enhanced glutamatergic afferent activity provides the presynaptic and postsynaptic coincidence necessary to initiate synaptic potentiation. In total, these synaptic events lead to a relatively long-lasting heightened activity of midbrain DA neurons. Consistent with other summarized studies, this work indicates that the synaptic changes normally associated with learning and memory can be influenced and commandeered during the nicotine addiction process.     

Age equivalence in switch costs for prosaccade and antisaccade tasks

This study examined age differences in task switching using prosaccade and antisaccade tasks. Significant specific and general switch costs were found for both young and old adults, suggesting the existence of 2 types of processes: those responsible for activation of the currently relevant task set and deactivation of the previously relevant task set and those responsible for maintaining more than 1 task active in working memory. Contrary to the findings of previous research, which used manual response tasks with arbitrary stimulus-response mappings to study task-switching performance, no age-related deficits in either type of switch costs were found. These data suggest age-related sparing of task-switching processes in situations in which memory load is low and stimulus-response mappings are well learned.     

Aging and the strategic control of the fixation offset effect

A study was conducted to examine potential age-related differences in the strategic control of exogenous and endogenous saccades within the context of the fixation offset effect (FOE; i.e., faster saccades when a fixation point is removed than when it is left on throughout a trial). Subjects were instructed to make rapid saccades either on the basis of a suddenly appearing peripheral visual stimulus (exogenous saccade) or in response to a tone (endogenous saccade). On half of the trials the fixation point was removed simultaneously with the occurrence of the cue stimulus. Subjects' preparatory set was varied by manipulating the proportion of saccades generated to a visual and auditory stimulus within a trial block. Young and old adults both produced FOEs, and the FOEs were strategically modulated by preparatory set. The data are discussed in terms of aging and oculomotor control.     

Generative Concern, Political Commitment, and Charitable Actions

The implications of psychosocial generativity (Erikson, 1950) for understanding contemporary politics were explored. Study 1 replicated, in two samples, previous findings that generativity concerns are related to a variety of political activities, including the expenditure of time and money in support of political organizations. Using path analyses, Study 2 extended these findings and demonstrated how midlife generativity concerns interacted with political orientation and interest in politics to produce stronger relationships with giving. These findings suggest that people view the political arena as one important way to improve society and thereby manifest cultural generativity. Although focusing on the domain of politics, these studies highlight the complexity of generativity as a construct; broad concerns with generativity operate within the context of ideological commitments to produce greater levels of generative activity.     

Evaluating a more cost-efficient alternative to providing in-home feedback to parents: the use of spousal feedback.

We evaluated the contribution of spousal feedback to a parent education curriculum designed for parents of children with autism. A modified multiple baseline design across 3 husband-and-wife dyads was used to examine the effects of teaching parents to give each other feedback on their teaching performance. For 5 of 6 participants, improvement in teaching performance occurred following didactic presentations. However, additional improvement was observed for 5 participants when the spousal feedback component was implemented.     

Agricultural research organizations: The assessment and improvement of performance

Public sector national agricultural research organizations (NARO)s are confronting the need to demonstrate performance, accountability, and results to maintain support and funding from investors. Current evaluation practices in NAROs are not performance oriented, nor are they applied at the organization level. A performance assessment system for NAROs is presented that integrates productivity and outcome evaluation with the assessment of key management activities influencing research outputs and impact. The system allows managers to record output levels over time and identify management weaknesses.