The impact of physical activity and sex differences on intraindividual variability in inhibitory performance in older adults

It is well-known that processing speed and executive functions decline with advancing age. However, physical activity (PA) has a positive impact on cognitive performances in aging, specifically for inhibition. Less is known concerning intraindividual variability (iiV) in reaction times. This study aims to investigate the influence of PA and sex differences on iiV in inhibitory performance during aging. Healthy adults were divided into active and sedentary groups according to PA level. To analyse iiV in reaction times, individual mean, standard deviation and the ex-Gaussian parameters were considered. An interaction between activity level and sex was revealed, sedentary females being slower and more variable than sedentary men. No sex differences were found in the active groups. These results indicate that the negative impact of sedentariness on cognitive performance in older age is stronger for females. The present findings underline the need to consider sex differences in active aging approaches.     

Training attentional control in older adults

ABSTRACT

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, η²?=?.57 to .90). Transfer to an analogous task was observed (ps <.05, η²?=?.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.     

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.     

Examining attentional biases underlying trait anxiety in younger and older adults

Previous research has not adequately assessed the independent contributions of component attentional processes to anxiety-linked biases. MacLeod and Sadler developed a novel, lexical decision task using negative and neutral word stimuli, to enable the independent measurement of attentional engagement and disengagement. Their results suggest that anxiety-linked attentional biases are associated with facilitated attentional engagement with negative information. The present study aimed to determine the replicability of these findings, with two important extensions. First, this study included positive word stimuli in the lexical decision task, to determine whether anxiety-linked attentional biases exist only towards negative information, or toward emotionally arousing information in general. Second, this study explored age-related differences in anxiety-linked attentional biases. Younger (N=32) and older adults (N=32) with both high and low trait anxiety completed the lexical decision task. The results suggest that heightened anxiety may be associated with a deficit in engaging with positive words. No age-related differences in anxiety-linked attentional biases were apparent.     

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.     

Time-of-day affects prospective memory differently in younger and older adults

The goal of this study was to investigate the impact of circadian arousal on prospective memory performance as a function of age. We tested a younger (18–34 years) and an older group (56–95 years) of participants on- and off-peak with regard to their circadian arousal patterns in a computer-based laboratory experiment. For the prospective memory task, participants had to press a particular key whenever specific target words appeared in an ongoing concreteness-judgment task. The results showed that prospective memory performance was better on- than off-peak in younger but not older participants. Younger participants consistently outperformed older participants in all conditions. We conclude that prospective remembering underlies time-of-day effects which most likely reflect controlled processes.     

Decision-making quality of younger and older adults in familiar and unfamiliar domains

Age-related differences in purchasing decisions were examined as a function of age and familiarity. On each trial, participants received purchasing options which varied in quality but ultimately cost the same amount of money. On half the trials, participants made decisions about items familiar to younger adults and on the other half of the trials, participants made decisions about products familiar to older adults. The participants’ task was to choose the option that provided the best value for the money. We were particularly interested in participants’ performance when inferencing was required to select the optimal option from the two choices. Younger adults outperformed older adults in unfamiliar but not familiar domains. It appeared that both younger and older adults used inferencing and elaborative processing to make the best decision in familiar domains but that only younger adults used inferencing and elaborative processing in unfamiliar domains.     

Impact of age-relevant goals on future thinking in younger and older adults

This study investigated how personal goals influence age differences in episodic future thinking. Research suggests that personal goals change with age and like autobiographical memory, future thinking is thought to be organised and impacted by personal goals. It was hypothesised that cueing older adults with age-relevant goals should modulate age differences in episodic details and may also influence phenomenological characteristics of imagined scenarios. Healthy younger and older adults completed the Future Thinking Interview [Addis, D. R., Wong, A. T., & Schacter, D. L. (2008). Age-related changes in the episodic simulation of future events. Psychological Science, 19(1), 33–41. doi:10.1111/j.1467-9280.2008.02043.x] adapted to activate age-appropriate goals. Narratives were scored with an established protocol to obtain objective measures of episodic and semantic details. Subjective features such as emotionality and personal significance showed age differences as a function of goal domain while other features (e.g., vividness) were unaffected. However, consistent with prior reports, older adults produced fewer episodic details than younger adults and this was not modulated by goal domain. The results do not indicate that goal activation affects level of episodic detail. With respect to phenomenological aspects of future thinking, however, younger adults show more sensitivity to goal activation, compared with older adults.     

The role of prior knowledge in error correction for younger and older adults

Previous work has demonstrated that, when given feedback, younger adults are more likely to correct high-confidence errors compared with low-confidence errors, a finding termed the hypercorrection effect. Research examining the hypercorrection effect in both older and younger adults has demonstrated that the relationship between confidence and error correction was stronger for younger adults compared with older adults. However, recent work suggests that error correction is largely related to prior knowledge, while confidence may primarily serve as a proxy for prior knowledge. Prior knowledge generally remains stable or increases with age; thus, the current experiment explored how both confidence and prior knowledge contributed to error correction in younger and older adults. Participants answered general knowledge questions, rated how confident they were that their response was correct, received correct answer feedback, and rated their prior knowledge of the correct response. Overall, confidence was related to error correction for younger adults, but this relationship was much smaller for older adults. However, prior knowledge was strongly related to error correction for both younger and older adults. Confidence alone played little unique role in error correction after controlling for the role of prior knowledge. These data demonstrate that prior knowledge largely predicts error correction and suggests that both older and younger adults can use their prior knowledge to effectively correct errors in memory.     

Sensitive performance-based assessment of everyday action in older and younger adults

Everyday function is compromised by mild cognitive changes in aging. These changes predict risk for future decline and dementia but remain poorly characterized, largely due to a scarcity of sensitive, objective measures.Twenty-seven younger adults and 25 non-demented older adults completed the Naturalistic Action Test (NAT), a performance-based measure of everyday action involving simple and complex tasks. Performance was coded for overt errors and subtle inefficiencies. Participants also completed self-report functional measures and cognitive tests. Mixed ANOVAs revealed that older adults made more subtle NAT errors with high task demands; groups did not differ in overt errors. Correlations did not reveal significant relations between self-report and NAT errors, but NAT performance was correlated with learning and recall.The NAT provides a promising tool for detecting subtle age-related changes and examining decline across levels of impairment. Self-report may lack sensitivity to subtle changes, and episodic memory changes underlie early functional disruption.     

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.     

Age differences in moral judgment: Older adults are more deontological than younger adults

In 2 studies, an older and a younger age group morally evaluated dilemmas contrasting a deontological judgment (do not harm others) against a utilitarian judgment (do what is best for the majority). Previous research suggests that deontological moral judgments are often underpinned by affective reactions and utilitarian moral judgments by deliberative thinking. Separately, research on the psychology of aging has shown that affect plays a more prominent role in the judgments and decision making of older (vs. younger) adults. Yet age remains a largely overlooked factor in moral judgment research. Here, we therefore investigated whether older adults would make more deontological judgments on the basis of experiencing different affective reactions to moral dilemmas as compared with younger adults. Results from 2 experiments indicated that older adults made significantly more deontological moral judgments. Mediation analyses revealed that the relationship between age and making more deontological moral judgments is partly explained by older adults exhibiting significantly more negative affective reactions and having more morally idealistic beliefs as compared with younger adults.     

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.     

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.     

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.     

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.     

Visual feature binding in younger and older adults: encoding and suffix interference effects

Three experiments investigated younger (18–25 yrs) and older (70–88 yrs) adults’ temporary memory for colour–shape combinations (binding). We focused upon estimating the magnitude of the binding cost for each age group across encoding time (Experiment 1; 900/1500?ms), presentation format (Experiment 2; simultaneous/sequential), and interference (Experiment 3; control/suffix) conditions. In Experiment 1, encoding time did not differentially influence binding in the two age groups. In Experiment 2, younger adults exhibited poorer binding performance with sequential relative to simultaneous presentation, and serial position analyses highlighted a particular age-related difficulty remembering the middle item of a series (for all memory conditions). Experiments 1–3 demonstrated small to medium binding effect sizes in older adults across all encoding conditions, with binding less accurate than shape memory. However, younger adults also displayed negative effects of binding (small to large) in two of the experiments. Even when older adults exhibited a greater suffix interference effect in Experiment 3, this was for all memory types, not just binding. We therefore conclude that there is no consistent evidence for a visual binding deficit in healthy older adults. This relative preservation contrasts with the specific and substantial deficits in visual feature binding found in several recent studies of Alzheimer's disease.