Adaptation to direction-dependent visuo-motor rotations and its decay in younger and older adults

We studied adaptation to a direction-dependent visuo-motor rotation in adults of early and late working age. For hand movements to the right, visual motion of the cursor on a monitor was rotated clockwise, for forward movements rotation of the cursor motion was zero, and for directions in-between rotation was intermediate. In contrast to previous studies, in which adaptation was more difficult (larger visuo-motor rotation, larger number of targets during practice) and the older age group was of higher age, we found no age-related deficit of adaptation. However, consistent with previous studies we found an age-related impairment of explicit knowledge of the visuo-motor rotation and no age-related differences of aftereffects. Across periods of not performing the task for 24 h and of performing the task for a prolonged period of time without visual feedback, we observed a decay of adaptation which did not depend on age. The present findings cast doubts on the prevalent interpretation of age-related impairments of adaptation in the absence of age-related changes of aftereffects as resulting from intentional strategic corrections, which become less efficient at higher age.     

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).     

Exploring interhemispheric collaboration in older compared to younger adults

Physical and Name Identity letter-matching tasks were used to explore differences in interhemispheric collaboration in younger and older adults. To determine whether other factors might also be related to across/within-hemisphere processing or visual field asymmetries, neuropsychological tests measuring frontal/executive functioning were administered, and comparisons were made for participants split into low and high efficiency groups based on performance on the letter-matching tasks. A Task by Across/Within interaction was found for both groups, but with a stronger within-hemisphere advantage for the Physical Task and a weaker across-hemisphere advantage for the Name Task for older participants. More efficient groups and better performers on several neuropsychological tasks showed a reduced across-hemisphere advantage for the Name Identity task. Findings suggest that computational complexity, specific task demands, and perhaps trade-offs between age-related changes in gray and white matter all contribute to whether processing loads are distributed across or within hemispheres as we age.     

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.     

Memory performance awareness in younger and older adults

Reports on the course of memory-monitoring skills across adulthood are discrepant in conclusions and limited in scope. The purpose of this study was to build a large data base (3 samples and 7 different tasks) to assess performance awareness. Younger (19-41 years) and older (59-93 years) Ss estimated performance either before (i.e., predictions) or after (i.e., postdictions) completing each task. Predictions were less accurate than postdictions at both age levels, suggesting Ss monitored performance during the study-test cycle. Overall, the data suggested no consistent age effects in performance awareness: Age differences in monitoring occurred only in predictions and only for some tasks. Between-tasks differences in age effects could not be attributed to a single mediating mechanism like those suggested in previous reports. Why previous research has produced conflicting conclusions about metacognitive development in adulthood is discussed in light of these data.     

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.     

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.     

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.     

Amygdala responses to emotionally valenced stimuli in older and younger adults

Abstract— As they age, adults experience less negative emotion, come to pay less attention to negative than to positive emotional stimuli, and become less likely to remember negative than positive emotional materials. This profile of findings suggests that, with age, the amygdala may show decreased reactivity to negative information while maintaining or increasing its reactivity to positive information. We used event-related functional magnetic resonance imaging to assess whether amygdala activation in response to positive and negative emotional pictures changes with age. Both older and younger adults showed greater activation in the amygdala for emotional than for neutral pictures; however, for older adults, seeing positive pictures led to greater amygdala activation than seeing negative pictures, whereas this was not the case for younger adults.     

Linking obsessional beliefs to OCD symptoms in older and younger adults

There are many open questions about the phenomenology of obsessive-compulsive disorder (OCD) in the elderly, and theories about the development of OCD have rarely been applied to older populations. The current study uses structural equation models to evaluate the relationship between obsessional beliefs and OCD symptoms across young and older adult age groups in a large community sample (aged 18-93; N=335), and to examine whether subjective concerns about cognitive decline partially mediate this relationship. Results support partial mediation, and follow-up analyses suggest that the pattern of relationships among subjective cognitive concerns, obsessional beliefs and OCD symptoms is invariant for younger and older adults, but older adults report relatively greater levels of subjective cognitive concerns.     

Spatial attention to arousing emotional stimuli in younger and older adults

Motivation and Emotion - Most work on emotional attention in aging has focused exclusively on stimulus valence, with very few studies systematically examining how younger and older adults may...     

Context affects feeling-of-knowing accuracy in younger and older adults

In feeling of knowing (FOK) studies, participants predict subsequent recognition memory performance on items that were initially encoded but that cannot presently be recalled. Research suggests that FOK judgment magnitude may be influenced by the total amount, or quantity, of contextual information retrieved related to the unrecalled target (e.g., Koriat, 1993). The present study examined the contribution of quality of that information to episodic FOK judgments. In addition, we tested whether the episodic FOK deficit demonstrated by older adults could be reduced by encouraging retrieval of contextual information relevant to the target. Three experiments demonstrated that quality of the retrieved partial information influenced FOK judgments in both older and younger adults; however, the manifestation of that influence was age dependent. The results also indicated that older adults required explicit retrieval of contextual information before making FOK judgments in order to make accurate FOK predictions. The results suggest that FOK accuracy may be partially determined by search processes triggered when participants are queried for contextual information.     

State-based versus reward-based motivation in younger and older adults

Recent decision-making work has focused on a distinction between a habitual, model-free neural system that is motivated toward actions that lead directly to reward and a more computationally demanding goal-directed, model-based system that is motivated toward actions that improve one’s future state. In this article, we examine how aging affects motivation toward reward-based versus state-based decision making. Participants performed tasks in which one type of option provided larger immediate rewards but the alternative type of option led to larger rewards on future trials, or improvements in state. We predicted that older adults would show a reduced preference for choices that led to improvements in state and a greater preference for choices that maximized immediate reward. We also predicted that fits from a hybrid reinforcement-learning model would indicate greater model-based strategy use in younger than in older adults. In line with these predictions, older adults selected the options that maximized reward more often than did younger adults in three of the four tasks, and modeling results suggested reduced model-based strategy use. In the task where older adults showed similar behavior to younger adults, our model-fitting results suggested that this was due to the utilization of a win-stay–lose-shift heuristic rather than a more complex model-based strategy. Additionally, within older adults, we found that model-based strategy use was positively correlated with memory measures from our neuropsychological test battery. We suggest that this shift from state-based to reward-based motivation may be due to age related declines in the neural structures needed for more computationally demanding model-based decision making.     

Factors influencing word naming in younger and older adults

The present study examined age differences in the influence of 3 factors that previous research has shown to influence word-naming performance. The influence of word frequency, orthographic length, and orthographic neighborhood measures was examined using large-scale regression analyses on the naming latencies for 2,820 words. Thirty-one younger adults and 29 older adults named all of these words, and age differences in the influence of these factors were examined. The results revealed that all 3 factors predicted reliable amounts of variance in word-naming latencies for both groups. However, older adults showed a larger influence of word frequency and reduced influences of orthographic length and orthographic neighborhood density compared with younger adults. Overall, these results suggest that lexical level factors increase in influence in older adults whereas sublexical factors decrease in influence.     

Monitoring one's own forgetting in younger and older adults

The present study examined whether there are age-related differences in the ability to accurately monitor forgetting. Young and older adults studied a mixed list of categorized words, and later recalled items when cued with each category. They then estimated the number of additional items that they did not recall-a form of monitoring one's forgetting. Older adults exhibited impaired memory performance compared with young adults, but also accurately estimated they forgot more information than young adults. Both age groups were fairly accurate in predicting forgetting in terms of resolution, indicating that aging does not impair the ability to monitor forgetting.     

Using warnings to reduce categorical false memories in younger and older adults

Warnings about memory errors can reduce their incidence, although past work has largely focused on associative memory errors. The current study sought to explore whether warnings could be tailored to specifically reduce false recall of categorical information in both younger and older populations. Before encoding word pairs designed to induce categorical false memories, half of the younger and older participants were warned to avoid committing these types of memory errors. Older adults who received a warning committed fewer categorical memory errors, as well as other types of semantic memory errors, than those who did not receive a warning. In contrast, young adults' memory errors did not differ for the warning versus no-warning groups. Our findings provide evidence for the effectiveness of warnings at reducing categorical memory errors in older adults, perhaps by supporting source monitoring, reduction in reliance on gist traces, or through effective metacognitive strategies.     

Cognitive monitoring and strategy choice in younger and older adults

Younger (24- to 39-year-old) and older (60- to 88-year-old) adults learned a list of vocabulary words; one half of the words were studied using a generally more powerful strategy (mnemonic keyword method), and one half mediated with a less powerful approach (generating semantic contexts). Before using these strategies as part of the experiment, neither younger nor older adults judged that the keyword method was more effective and neither group preferred one strategy over the other. After using the strategies and taking a test of strategically studied unfamiliar vocabulary words, the younger subjects reported accurately the relative effectiveness of the two strategies and selected the one that had worked better for them to apply to a subsequent list of vocabulary items. The older participants were not as aware of the differential potency of the strategies and did not rely as much as did the younger subjects on knowledge of strategy utility in making strategy choices. In short, metacognitive awareness of strategy effects produced by monitoring and use of metacognitive awareness in regulating strategy choice were more pronounced in the younger compared with the older sample in this study.     

Implicit and explicit components of dual adaptation to visuomotor rotations

Concurrent adaptation to two different visuomotor transformations has been shown to be possible as long as discriminative contextual cues are available. The authors examined explicit and implicit components of visually cued dual adaptation in younger and older adults. They found that only young adults, but not old adults, produced appropriate adaptive shifts of hand-movement direction to compensate for the visuomotor rotations. Aftereffects, conceived as a measure of implicit knowledge, were only poorly developed. Furthermore, only participants in the younger group exhibited systematic explicit knowledge of the visuomotor rotations. Subsequent analyses revealed strong correlations between the quality of explicit knowledge and the overall visuomotor adaptation. Thus, visually cued dual adaptation to two opposite visuomotor rotations is primarily mediated by conscious strategic corrections based on explicit knowledge of the transformations, a process, which is selectively impaired in older adults.