Training attentional control in older adults

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n?=?21). Training gains after 5 days and extent of transfer was compared to another subset (n?=?20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η(2)?=?.57 to .90). Transfer to an analogous task was observed (ps <.05, η(2)?=?.10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context.     

Effects of context expectation on prospective memory performance among older and younger adults

This experiment examined the impact of context expectation on prospective memory (PM) performance among older and younger adults. Participants responded to PM target words embedded in an ongoing lexical decision task (LDT). Older and younger adults performed similarly on the PM task. Regardless of age, PM was significantly better for participants in the correct context expectation condition and significantly worse in the incorrect context expectation condition relative to participants who held no expectations about the context in which targets would appear. Participants’ LDT response latencies were used to assess cost of the PM task to the ongoing task. Latencies were discernibly longer in the LDT block where the PM targets were expected compared to the block where they were not expected. The findings provide new information about how context can be used to support PM aging and suggest that contextual information can be equally beneficial for older and younger adults.     

A dichotic listening study of attention control in older adults

The influence of age on attentional control of bottom-up processing was investigated with a dichotic-listening paradigm. The typical right-ear-advantage (REA) without specific attentional instructions was used as a measure of bottom-up processing (non-forced condition). Top-down attentional control was evaluated by instructing subjects to report only the right or left ear stimulus of the dichotic pair (forced-right, forced-left conditions). Both young and old participants showed a REA in the non-forced condition and an increased REA in the forced-right condition. The old group failed, however, to use attention to modulate the REA to the same degree as the younger participants in the forced-left condition. Only the young group showed a significant left ear advantage (LEA). The results are discussed in relation to cognitive decline in normal aging and in early stages of dementia.     

Activation of emotion information in text among younger and older adults

The ability to represent emotions is an important capacity for the understanding of discourse. In the current literature, it is unclear whether older adults represent emotion information in the course of language processing, in particular as it relates to developing an adequate mental model of characters in narratives. We addressed this issue in two studies, one assessing emotion activation at the word level and the other at the mental model level. In the first experiment, subjects performed a lexical decision task in which words were drawn from both logic- and emotion-based categories. For both category types, priming was evident for young and old. In the second experiment, subjects read passages with emotion information that was consistent or inconsistent with the implied emotional tone. Both age groups showed an increase in reading time in response to inconsistent emotion information, indicating that the protagonist's emotional state was represented while reading. Results of these studies generally suggest age preservation in the activation of emotion information in language processing.     

Process and strategy in memory for speech among younger and older adults

Younger and older adults listened to and immediately recalled short passages of speech that varied in the rate of presentation and in the degree of linguistic and prosodic curing. Although older adults showed a differential decrease in recall performance as a function of increasing speech rate, age differences in recall were reduced by the presence of linguistic and prosodic cues. Under conditions of optimum linguistic redundancy, older adults were also found to add more words and to make more meaning-producing reconstructions in recall. Differences in overall performance are accounted for in terms of age-related changes in working memory processing and strategy utilization.     

Gender differences in social support among older adults

The purpose of this study was to determine whether exposure to life stress can help explain gender differences in the use of social support. Findings from a longitudinal study suggest that as the number of stressful life events increase, elderly men and women are equally likely to become more involved in their social network, while gender differences emerge only in response to chronic financial strain. Further analysis indicates that elderly women are more likely than elderly men to report that the support they received increased their feelings of personal control.     

Age-related differences in attentional networks of alerting and executive control in young, middle-aged, and older Chinese adults

Previous studies suggest that aging is associated with impairment of attention. However, it is not known whether this represents a global attentional deficit or relates to a specific attentional network. We used the attention network test to examine three groups of younger, middle-aged, and older participants with respect to the efficiency of three anatomically defined attentional networks: alerting network, orienting network, and executive control network. Age-related change was found to have the greatest effect on the executive network and the least effect on the alerting network as well as on overall mean response time. Impairment of the orienting network was found to be insignificant. Age-related deterioration of the prefrontal lobe, the dopaminergic system, and function of specific genes may explain the age-related changes in executive attention, which occur after the fourth decade of life.     

Holistic face processing among school children,younger and older adults

While previous studies have mostly examined holistic face processing in childhood and young adulthood, the present study investigated developmental changes of holistic face processing under a lifespan perspective, including older adulthood. Children 5–7 and 9–10 years of age, as well as young and older adults were instructed to assign faces into two categories. The categories were constructed to allow either a holistic categorization according to the overall face similarities or an analytical categorization by focusing on single facial features. The results show an increase in holistic face processing from childhood to young adulthood and a decrease towards older adulthood. Features used for categorization changed from internal to external features with age. Thus, crucial changes of face processing occur beyond young adulthood.     

Dual-task processing in younger and older adults: similarities and differences revealed by fMRI

fMRI was used to explore age differences in the neural substrate of dual-task processing. Brain activations when there was a 100 ms SOA between tasks, and task overlap was high, were contrasted with activations when there was a 1000 ms SOA, and first task processing was largely complete before the second task began. Younger adults (M=21 yrs) showed activation in dorsolateral prefrontal cortex and in parietal areas as well as in ventral medial frontal cortex and sub-lobar areas. Activations in older adults (M=71 yrs) did not differ significantly from younger adults except for higher activations in occipital and polar prefrontal cortex. The results were well fit by a model with two networks managing dual-task interference, a medial prefrontal network that detects changes in the stimulus situation and maps them to associated changes in the valence of response mappings and a lateral frontal-parietal network that initiates and carries out the shift from one task to the other. The additional activations in older adults as a group and the correlations of individual differences in activation with performance were consistent with recruitment within each of these networks. Alternative explanations such as hemispheric asymmetry reduction and reactive rather than proactive processing in older adults were not supported.     

Electrophysiological response during source memory decisions in older and younger adults

We recorded event-related potentials (ERPs) as individuals made source monitoring decisions in a paradigm in which the influence of item familiarity and goal relevance could be separately evaluated. Younger and older adults read a list of words and subsequently distinguished these words from foils in a running recognition test in which some foils were repeated after a lag of 6 items, creating familiar lures. Behaviorally, older and younger adults performed equally well in the recognition of study words and the rejection of singly presented foils. However, older adults were more likely to respond to the familiar lures as though they had come from the study list, thus producing the expected group difference in source-monitoring error. For younger adults the ERPs elicited by the targeted study words were maximal at posterior sites and significantly greater than those elicited by either familiar lures or foils. Older adults generated far less differentiated ERP waveforms but with a markedly greater amplitude at frontal sites. We interpret this frontal maximum in the context of poorer source monitoring as suggesting that older adults are more dependent on controlled processes to make discriminations that seem to occur much earlier and more automatically for younger adults.     

Memory complaints in younger and older adults

Two samples of older and younger subjects were administered a series of memory tasks and questionnaires tapping their perceptions about their own memory functioning. As in previous research, memory performance was usually better in the younger than in the older sample. In contrast, perceptions about memory varied little as a function of age, and these subjective reports were not related to objective memory performances. These results are relevant to theories that metacognition plays an important role in mediating performance declines with advancing age. If metacognition is implicated in age-related memory differences, it is some aspect of metacognition other than long-term beliefs about memory functioning (e. g. short-term perceptions that occur while attempting to perform memory tasks).     

The transient nature of executive control processes in younger and older adults

In this paper I review data from recent studies supporting the hypothesis that executive control processes fluctuate in efficiency over time and that these fluctuations are more pervasive in older than younger adults. Patterns of response accuracy in tasks requiring selective attention and prospective memory reveal that lapses of intention are often preceded and followed by periods of goal-directed action. Analysis of response time distributions reveals that increased performance variability in older adults for task conditions requiring executive control results from an increase in the degree of positive skewing of the distribution. Together, these findings lead to the suggestion that disruptions of executive control processes supporting performance in demanding tasks are temporally limited in nature. Data from recent neurophysiological studies indicates a possible role of the prefrontal cortex in maintaining optimal levels of executive control.     

Intraindividual reaction time variability predicts prospective memory failures in older adults

This study investigated the relationship between intraindividual variability (IIV) in reaction time and prospective memory errors in older adults using data from the Zurich Longitudinal Study of Cognitive Aging (n = 336 individuals aged 66–81 years). The results indicated that increased IIV measured from independent tasks was associated with a greater proportion of prospective memory errors. These significant findings were not influenced by age and did not vary according to prospective memory cue type. Variability is thought to reflect fluctuations in attentional and executive control and these attentional processes may also impact on prospective memory through failure to detect the target cue. The findings suggest, therefore, that measures of variability may have some potential in the identification of older persons who are more vulnerable to everyday errors such as prospective memory failures.     

Random noun generation in younger and older adults

We examined age-related changes of executive functions by means of random noun generation. Consistent with previous observations on random letter generation, older participants produced more prepotent responses than younger ones. In the case of random noun generation, prepotent responses are nouns of the same category as the preceding noun. In contrast to previous observations, older participants exhibited stronger repetition avoidance and a stronger tendency toward local evenness—that is, toward equal frequencies of the alternative responses even in short subsequences. These data suggest that at higher adult age inhibition of prepotent responses is impaired. In addition, strategic attentional processes of response selection are strengthened, in particular the application of a heuristic for randomness. In this sense response selection is more controlled in older than in younger adults.     

Auditory negative priming in younger and older adults

Two experiments are reported in which performance of old and young adults in an auditory negative priming task was compared. Auditory negative priming was not smaller in old than in young adults. This result was independent of whether or not conditions were present that had previously been assumed to favour episodic retrieval, as opposed to inhibitory processes, as a basis of the negative priming phenomenon. The data from the present auditory negative priming experiments are incompatible with the global assumption that the efficiency of inhibitory attentional processes in general diminishes across the adult life span.     

Part-set cuing effects in younger and older adults

In 3 experiments, the authors examined part-set cuing effects in younger and older adults. Participants heard lists of category exemplars and later recalled them. Recall was uncued or cued with a subset of studied items. In Experiment 1, participants were cued with some of the category names, and they remembered fewer never-cued categories than a free-recall condition. In Experiment 2, a similar effect was observed for category exemplar cues. There was also an age difference: By some measures, a small number of cues impaired older adults more than younger. Experiment 3 replicated this result and found that older adults were disproportionately slow in the presence of cues. Across experiments, older adults showed robust part-set cuing effects, and sometimes, they were disproportionately impaired by cues.     

Pictorial rehearsal effects in younger and older adults

Abstract

In three studies, we examined pictorial rehearsal effects in younger and older adults. Concrete and abstract line drawings that varied in the amount of pictorial detail were presented for study under different presentation conditions. In the pictorial rehearsal condition, each picture was followed by a blank rehearsal interval where the picture was no longer presented. In all three experiments, the poststimulus interval enhanced picture recognition for both age groups, relative to a control condition where no rehearsal interval occurred. These findings suggest that older adults, like younger adults, form and maintain visual images across a blank rehearsal interval. Implications of these findings for current views on imaginal processes in older adults are discussed.