Dual-task costs of texting while walking forward and backward are greater for older adults than younger adults

Cognitive-motor dual-tasking involves concurrent performance of two tasks with distinct cognitive and motor demands and is associated with increased fall risk. In this hypothesis-driven study, younger (18–30 years, n = 24) and older (60–75 years, n = 26) adults completed six walking tasks in triplicate. Participants walked forward and backward along a GAITRite mat, in isolation or while performing a verbal fluency task. Verbal fluency tasks involved verbally listing or typing on a smartphone as many words as possible within a given category (e.g., clothes). Using repeated measures MANOVA models, we examined how age, method of fluency task (verbal or texting), and direction of walking altered dual-task performance. Given that tasks like texting and backward walking require greater cognitive resources than verbal and forward walking tasks, respectively, we hypothesized older adults would show higher dual-task costs (DTCs) than younger adults across different task types and walking directions, with degree of impairment more apparent in texting dual-task trials compared to verbal dual-task trials. We also hypothesized that both age groups would have greater DTCs while walking backward than while walking forward, regardless of task.Independent of age group, velocity and stride length were reduced for texting compared to the verbal task during both forward and backward walking; cadence and velocity were reduced while walking forward compared to walking backward for the texting task; and stride length was reduced for forward walking compared to backward walking during the verbal task. Younger adults performed better than older adults on all tasks with the most pronounced differences seen in velocity and stride length during forward-texting and backward-texting. Interaction effects for velocity and stride length while walking forward indicated younger adults performed better than older adults for the texting task but similarly during the verbal task. An interaction for cadence during the verbal task indicated younger adults performed better than older adults while walking backward but similarly while walking forward.In summary, older adults experienced greater gait decrement for all dual-task conditions. The greater declines in velocity and stride length in combination with cadence being stable suggest reductions in velocity during texting were due to shorter strides rather than a reduced rate of stepping. Contrary to our hypotheses, we found greater DTCs while walking forward rather than backward, which may be due to reduced gait performance during single-task backward walking; thus, further decrements with dual-tasking are unlikely. These findings underscore the need for further research investigating fall risk potential associated with texting and walking among aging populations and how interventions targeting stride length during dual-task circumstances may improve performance.     

Similarity-based interference in a working memory numerical updating task: age-related differences between younger and older adults

Similarity among representations held simultaneously in working memory (WM) is a factor which increases interference and hinders performance. The aim of the current study was to investigate age-related differences between younger and older adults in a working memory numerical updating task, in which the similarity between information held in WM was manipulated. Results showed a higher susceptibility of older adults to similarity-based interference when accuracy, and not response times, was considered. It was concluded that older adults' WM difficulties appear to be due to the availability of stored information, which, in turn, might be related to the ability to generate distinctive representations and to the process of binding such representations to their context when similar information has to be processed in WM.     

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.     

Spatial updating of multiple targets: Comparison of younger and older adults

When walking without vision, people mentally keep track of the directions and distances of previously viewed objects, a process called spatial updating. The current experiment indicates that while people across a large age range are able to update multiple targets in memory without perceptual support, aging negatively affects accuracy, precision, and decision time. Participants (20 to 80 years of age) viewed one, three, or six targets (colored lights) on the floor of a dimly lit room. Then, without vision, they walked to a target designated by color, either directly or indirectly (via a forward turning point). The younger adults’ final stopping points were both accurate (near target) and precise (narrowly dispersed), but updating performance did degrade slightly with the number of targets. Older adults’ performance was consistently worse than the younger group, but the lack of interaction between age and memory load indicates that the effect of age on performance was not further exacerbated by a greater number of targets. The number of targets also significantly increased the latency required to turn toward the designated target for both age groups. Taken together, results extend previous work showing impressive updating performance by younger adults, with novel findings showing that older adults manifest small but consistent degradation of updating performance of multitarget arrays.     

Hypermnesia: Age-related differences between young and older adults

Hypermnesia is a net improvement in memory performance that occurs across tests in a multitest paradigm with only one study session. Our goal was to identify possible age-related differences in hypermnesic recall. We observed hypermnesia for young adults using verbal (Experiment 1) as well as pictorial (Experiment 2) material, but no hypermnesia for older adults in either experiment. We found no age-related difference in reminiscence (Experiments 1 and 2), though there was a substantial difference in intertest forgetting (Experiments 1 and 2). Older, relative to young, adults produced more forgetting, most of which occurred between Tests 1 and 2 (Experiments 1 and 2). Furthermore, older, relative to young, adults produced more intrusions. We failed to identify a relationship between intrusions and intertest forgetting. We suggest that the age-related difference in intertest forgetting may be due to less efficient reinstatement of cues at test by older adults. The present findings reveal that intertest forgetting plays a critical role in hypermnesic recall, particularly for older adults.     

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.     

Causal attributions and strategy use in relation to memory performance differences in younger and older adults

A metacognitive hypothesis to explain age differences in adult memory is explored here–that younger and older adults differ in beliefs about memory and strategic processing. The motivational beliefs that adults make for their own memory performances were examined across tests of recall, recognition, face–name learning, and appointment-keeping. Forty-eight older and 48 younger community-living adults were required to report the factors they believed influenced their performance and the memory strategies used for each task. A final questionnaire required subjects to rank order the importance of a list of causal factors. There were significantly more younger adults as compared to older adults who attributed performance to controllable factors (i.e. strategy use), although age differences in beliefs on a more familiar memory task were smaller than on other tasks. Moreover, within age groups, attributions to controllable factors were associated with increased memory performance compared to when memory was attributed to uncontrollable factors (i.e. ability, age). Believing that memory is uncontrollable may undermine the efficient use of effort in cognition, consistent with current metacognitive theory.     

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.     

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 brain electrical activity during extended continuous face recognition in younger children, older children and adults

To examine the development of recognition memory in primary-school children, 36 healthy younger children (8-9 years old) and 36 healthy older children (11-12 years old) participated in an ERP study with an extended continuous face recognition task (Study 1). Each face of a series of 30 faces was shown randomly six times interspersed with distracter faces. The children were required to make old vs. new decisions. Older children responded faster than younger children, but younger children exhibited a steeper decrease in latencies across the five repetitions. Older children exhibited better accuracy for new faces, but there were no age differences in recognition accuracy for repeated faces. For the N2, N400 and late positive complex (LPC), we analyzed the old/new effects (repetition 1 vs. new presentation) and the extended repetition effects (repetitions 1 through 5). Compared to older children, younger children exhibited larger frontocentral N2 and N400 old/new effects. For extended face repetitions, negativity of the N2 and N400 decreased in a linear fashion in both age groups. For the LPC, an ERP component thought to reflect recollection, no significant old/new or extended repetition effects were found. Employing the same face recognition paradigm in 20 adults (Study 2), we found a significant N400 old/new effect at lateral frontal sites and a significant LPC repetition effect at parietal sites, with LPC amplitudes increasing linearly with the number of repetitions. This study clearly demonstrates differential developmental courses for the N400 and LPC pertaining to recognition memory for faces. It is concluded that face recognition in children is mediated by early and probably more automatic than conscious recognition processes. In adults, the LPC extended repetition effect indicates that adult face recognition memory is related to a conscious and graded recollection process rather than to an automatic recognition process.     

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.     

Interindividual differences in attentional control profiles among younger and older adults

This study aimed at characterizing the individual variability in three attentional control functions (shifting, inhibition, and updating), among 75 older and 75 younger adults. It also examined the intellectual and health variables associated with different cognitive profiles. Cluster analyses identified three separate attentional control profiles for both age groups, but the patterns of variability were strikingly different. Younger adults’ profiles were characterized by homogeneous performance across domains and differed only in their overall level of performance. In contrast, older adults’ profiles were characterized by uneven levels of performance across domains and inhibition stood out as critical in distinguishing between profiles. One subgroup of older adults had poor inhibition and more adverse lifestyle characteristics and appeared more cognitively vulnerable. In conclusion, subgroups of younger and older adults with different attentional control profiles can be identified, but the expression of variability changes with age as older adults’ profiles become more heterogeneous.     

Memory prediction accuracy in younger and older adults: a cross-sectional and longitudinal analysis

Across three experiments, the effects of age and normative information on memory prediction accuracy were examined. In Experiment 1, younger and older adults were given an arbitrary midpoint anchor and made global predictions about how they expected to perform on subsequent verbal, visual, and name-face memory tasks. In Experiment 2, the normative information was varied by providing participants with a midpoint anchor, accurate anchor, or no anchor. Across both experiments, older adults successfully adjusted their predictions in accordance with the task demands, regardless of the type of normative information given. In Experiment 3, older adults' prediction accuracy was measured at a 5-year follow-up. Memory performance predictions were found to be just as accurate as they had been at the first assessment. In general, the findings indicate that older adults were as accurate as younger adults in assessing their memory performance abilities. Older adults also did not operate on a negative stereotype of global cognitive decline with age, as they provided varying performance estimates across the different domains and types of memory tasks.     

When the mind wanders: Age-related differences between young and older adults

Interest in mind wandering (MW) has grown in recent years, but few studies have assessed this phenomenon in older adults. The aim of this study was to assess age-related differences between young, young–old and old–old adults in MW using two versions of the sustained attention to response task (SART), one perceptual and one semantic. Different indicators were examined (i.e., reported MW episodes and behavioral indices of MW such as response time latency and variability, incorrect response and omission errors). The relationship between MW, certain basic mechanisms of cognition (working memory, inhibition and processing speed), cognitive failures and intrusive thoughts in everyday life was also explored. Findings in both versions of the SART indicated that older adults reported a lower frequency of MW episodes than young adults, but some of the behavioral indices of MW (response time variability, incorrect response and omission errors) were higher in old–old adults. This seems to suggest that MW becomes less frequent with aging, but more pervasive and detrimental to performance. Our results also indicated that the role of age and cognitive mechanisms in explaining MW depends on the demands of the SART task considered.     

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.     

Individual differences in cognitive plasticity: an investigation of training curves in younger and older adults

To date, cognitive intervention research has provided mixed but nevertheless promising evidence with respect to the effects of cognitive training on untrained tasks (transfer). However, the mechanisms behind learning, training effects and their predictors are not fully understood. Moreover, individual differences, which may constitute an important factor impacting training outcome, are usually neglected. We suggest investigating individual training performance across training sessions in order to gain finer-grained knowledge of training gains, on the one hand, and assessing the potential impact of predictors such as age and fluid intelligence on learning rate, on the other hand. To this aim, we propose to model individual learning curves to examine the intra-individual change in training as well as inter-individual differences in intra-individual change. We recommend introducing a latent growth curve model (LGCM) analysis, a method frequently applied to learning data but rarely used in cognitive training research. Such advanced analyses of the training phase allow identifying factors to be respected when designing effective tailor-made training interventions. To illustrate the proposed approach, a LGCM analysis using data of a 10-day working memory training study in younger and older adults is reported.     

Formal reasoning in Japanese older adults: The role of metacognitive strategy,task content,and social factors

This study investigated the availability of deductive reasoning competence in late adulthood. Forty-six Japanese older (mean age =71 years) and 58 Japanese young adults (mean age =19.6 years) were assessed for formal or deductive reasoning using Overton's (1990) revision of the four-card selection task. For older adults, metacognitive strategy—operating as a procedure designed to access reasoning competence—resulted in enhanced performance levels. When the semantic content of the reasoning task involved emotional issues, however, the metacognitive strategy failed to facilitate reasoning performance. This suggests that reasoning competence is available in late adulthood but that performance is susceptible to contextual variables. Social factors were not significantly related to older adults' reasoning performance. Thus, assessment of these factors may have been based on too broad a definition to describe adequately the status of the older adults. For the young, only semantic task content was related to reasoning performance.     

False recognition of abstract versus common objects in older and younger adults: testing the semantic categorization account

Older adults often demonstrate higher levels of false recognition than do younger adults. However, in experiments using novel shapes without preexisting semantic representations, this age-related elevation in false recognition was found to be greatly attenuated. Two experiments tested a semantic categorization account of these findings, examining whether older adults show especially heightened false recognition if the stimuli have preexisting semantic representations, such that semantic category information attenuates or truncates the encoding or retrieval of item-specific perceptual information. In Experiment 1, ambiguous shapes were presented with or without disambiguating semantic labels. Older adults showed higher false recognition when labels were present but not when labels were never presented. In Experiment 2, older adults showed higher false recognition for concrete but not abstract objects. The semantic categorization account was supported.     

Alternative mechanisms for improvements in fluid ability performance among older adults

To cross-validate and extend previous work regarding fluid ability training, I randomly assigned 256 community-living older participants to either induction training, stress inoculation training, or nocontact control groups. Practice effects were common to almost all of the ability measures, whereas training effects were specific to measures of inductive reasoning. Both training groups demonstrated greater immediate posttest gains in Letter Sets performance relative to control groups, which were maintained to the greatest extent one month later for the induction training group. The control and stress inoculation groups experienced slight declines one month later, although performance differences still favored the later. For Letter Series, one week follow-up findings favored both induction and stress inoculation conditions, whereas only the stress inoculation group demonstrated gains at one month follow-up. No differential pattern of training transfer to other components of Gf-Gc was observed. These data suggest alternative means by which the facilitation of intellectual competence in older adults may be accomplished.