Age-related effects of attentional and oculomotor capture by onsets and color singletons as a function of experience

The present experiment examined the degree to which experience with different stimulus characteristics affects attentional capture, particularly as related to aging. Participants were presented with onset target/color singleton distractor or color singleton target/onset distractor pairs across three experimental sessions. The target/distractor pairs were reversed in the second session such that the target in the first session became the distractor in the second and third sessions. For both young and old adults previous experience with color as a target defining feature influenced oculomotor capture with task-irrelevant color distractors. Experience with sudden onsets had the same effect for younger and older adults, although capture effects were substantially larger for onset than for color distractors. Experience-based capture effects diminished relatively rapidly after target and distractor-defining properties were reversed. The results are discussed in terms of top-down and stimulus-driven effects on age-related differences in attentional control.     

Fitness effects on the cognitive function of older adults: a meta-analytic study

A meta-analytic study was conducted to examine the hypothesis that aerobic fitness training enhances the cognitive vitality of healthy but sedentary older adults. Eighteen intervention studies published between 1966 and 2001 were entered into the analysis. Several theoretically and practically important results were obtained. Most important, fitness training was found to have robust but selective benefits for cognition, with the largest fitness-induced benefits occurring for executive-control processes. The magnitude of fitness effects on cognition was also moderated by a number of programmatic and methodological factors, including the length of the fitness-training intervention, the type of the intervention, the duration of training sessions, and the gender of the study participants. The results are discussed in terms of recent neuroscientific and psychological data that indicate cognitive and neural plasticity is maintained throughout the life span.     

The impact of father absence on adolescent separation-individuation

The authors compared separation-individuation and psychological separation from fathers of 25 adolescent boys who were living with both biological parents with that of 25 boys who were living with their biological mothers in homes in which the fathers did not reside. The results showed that the boys in the 2 groups did not differ on measures of separation-individuation and that the quality of the mother-son relationship mediated several of the assessed separation-individuation manifestations. The authors' initial data analysis with regard to psychological separation showed that boys who lived in homes in which the father was a nonresident were more separated on 2 of the 4 dimensions assessed; however, when controlled for quality of mother-son and father-son relationship, these differences were not significant. The frequency of father contact in homes in which the father did not reside was positively correlated with healthy separation but negatively correlated with functional, attitudinal, and emotional independence from the father. The results of the study support the importance of the quality of a child's relationship with his or her mother and father as a mediator of several dimensions of the separation-individuation process.     

Prioritization by transients in visual search

There is an ongoing debate as to whether prioritizing new objects over old objects (the so-calledpreview benefit) is the result of top-down inhibition of old objects (i.e., visual marking; Watson & Humphreys, 1997) or attentional allocation to new objects, presented with a luminance transient (Donk & Theeuwes, 2001). In the two experiments reported here, we tested whether prioritization by luminance transients alone can produce a subset-selective search similar to the preview effect. Subjects viewed multiobject displays while a subset of objects was briefly flashed. The subjects prioritized up to 14 flashed objects over at least 14 nonflashed objects. Since prioritization by luminance transients can produce a subsetselective search on its own, it may well play an important role in the preview benefit.     

Attentional control in the aging brain: insights from an fMRI study of the stroop task

Several recent studies of aging and cognition have attributed decreases in the efficiency of working memory processes to possible declines in attentional control, the mechanism(s) by which the brain attempts to limit its processing to that of task-relevant information. Here we used fMRI measures of neural activity during performance of the color-word Stroop task to compare the neural substrates of attentional control in younger (ages: 21-27 years old) and older participants (ages: 60-75 years old) during conditions of both increased competition (incongruent and congruent neutral) and increased conflict (incongruent and congruent neutral). We found evidence of age-related decreases in the responsiveness of structures thought to support attentional control (e.g., dorsolateral prefrontal and parietal cortices), suggesting possible impairments in the implementation of attentional control in older participants. Consistent with this notion, older participants exhibited more extensive activation of ventral visual processing regions (i.e., temporal cortex) and anterior inferior prefrontal cortices, reflecting a decreased ability to inhibit the processing of task-irrelevant information. Also, the anterior cingulate cortex, a region involved in evaluatory processes at the level of response (e.g., detecting potential for error), showed age-related increases in its sensitivity to the presence of competing color information. These findings are discussed in terms of newly emerging models of attentional control in the human brain.     

Pitch and loudness interact in auditory displays: can the data get lost in the map?

Many auditory displays use acoustic attributes such as frequency, intensity, and spectral content to represent different characteristics of multidimensional data. This study demonstrated a perceptual interaction between dynamic changes in pitch and loudness, as well as perceived asymmetries in directional acoustic change, that distorted the data relations represented in an auditory display. Three experiments showed that changes in loudness can influence pitch change, that changes in pitch can influence loudness change, and that increases in acoustic intensity are judged to change more than equivalent decreases. Within a sonification of stock market data, these characteristics created perceptual distortions in the data set. The results suggest that great care should be exercised when using lower level acoustic dimensions to represent multidimensional data.     

Influence of single and multiple onset distractors on visual search for singleton targets

In three experiments, we examined attentional and oculomotor capture by single and multiple abrupt onsets in a singleton search paradigm. Subjects were instructed to move their eyes as quickly as possible to a color singleton target and to identify a small letter located inside of it. In Experiment 1, task-irrelevant sudden onsets appeared simultaneously on half the trials with the presentation of the color singleton target. Response times (RTs) were longer when onsets appeared in the display regardless of the number of onsets. Eye-scan strategies were also disrupted by the appearance of the onset distractors, although the proportion of trials on which the eyes were directed to the onsets was the same regardless of the number of onsets. In Experiment 2, we manipulated the time of presentation of two task-irrelevant onsets in order to further examine whether multiple onsets would be attended and fixated prior to attending a color singleton target. Again, subjects made a saccade to a task-irrelevant onset on a substantial proportion of trials prior to fixating the target. However, saccades to the second onset were rare. Experiment 3 served as a replication of Experiment 1 but without the requirement for subjects to move their eyes to detect and identify the singleton target. The RT results were consistent with those in Experiment 1; dual onsets had no larger an effect on response speed than single onset distractors. These data are discussed in terms of the interaction between top-down and bottom-up control of attention and the eyes.     

The future of the voluntary agency in a mixed economy.

The growing reliance of voluntary nonprofit organizations on governmental funds ties their future to the fate of the welfare state. A mixed, three-sector, social service economy has blurred organizational differences and made a more rational division of responsibility unlikely. This article suggests that the traditional roles of voluntary agencies can still be reformulated to suggest a more realistic view of their distinctive areas of competence and vulnerability. To avoid goal deflection in the future, the author concludes that voluntary agencies must cope effectively with the dilemmas of entrepreneurialism and vendorism.     

Alcohol beverage cues impair memory in high social drinkers

This study examined the influence of an alcohol beverage cue on memory processes in social drinkers. High and low drinking college students viewed a series of 15 pictures of common objects with the eighth picture either of an alcohol beverage or a soda. For high drinkers, free recall of the alcohol picture was enhanced, and memory for the pictures immediately following the cue was suppressed, relative to the series containing the soda picture. No such effects were observed for light drinkers. Apparently, alcohol cues affect attention and memory in heavy social drinkers. These results have important implications for theories of memory and attention, for explanations of addictive behaviour, and for effective prevention and treatment of alcoholism.     

Comparison selection: An approach to the study of consumer judgment and choice

We introduce an alternative perspective on the study of consumer judgment and decision making, which is based on the notion that judgment and choice problems consist of comparisons that decision makers might select. Our new perspective proposes that if we can predict the likelihood that particular comparisons will become focal in a judgment or choice task, we will be able to gain a better understanding of and anticipate the resulting effect. Building on related literatures, we propose that comparison selection is driven by the task's latitude of acceptance (LOA) and comparison fluency (i.e., the overall ease of making that comparison). The task's LOA curve represents the range and concentration of potentially acceptable comparisons, whereas comparison fluency refers to the salience and ease of making the comparison. We illustrate our approach using previously studied problems (e.g., choice, variety seeking, the “jacket and calculator” problem, and contingent valuation) as well as new empirical tests.