Patellofemoral kinematics in healthy older adults during gait activities

The patellofemoral (PF) joint is susceptible to many pathologies resulting from acute injury, chronic disease and complications following surgical treatment of the knee. The objectives of this study were to describe case series measurements of patellar motion in healthy older adults as they performed three gait activities, determine patellar tendon angle and moment arm, and show if these quantities were activity dependent. A stereo radiography system was utilized to obtain the 3D PF kinematics of seventeen healthy people over 55 years of age (8F/9M, 66 ± 7.9 years old, 75.7 ± 20.5 kg) as they performed level walking, a step down, and a pivot turn. For a similar portion of the gait cycle, patellar flexion (6.2° ± 5.8) and average range of motion (ROM) (11.0° ± 5.9°) for walking with a step down was greater compared to the other gait activities (gait ROM 6.9° ± 4.3°, pivot ROM 5.7° ± 3.3°), while the average range of motion for patella tilt was greater during walking with a pivot turn (8.6° ± 3.9°). However, each subject displayed distinct PF kinematic trends during all activities with a few notable exceptions. Importantly, the knee extensor mechanism characteristics of patellar tendon angle and moment arm showed considerable variation across subjects but were largely unaltered by changing activities. The variation between subjects and the different behavior of the patella during the step down and pivot emphasized the need for analysis of a range of activities to reveal individual response to pathology and treatment in patellar maltracking and osteoarthritis.     

Judgments of blame and forgiveness: A comparison of young adults,older adults,and older adults with dementia

IntroductionAlzheimer's disease may modify moral judgment.ObjectiveIn two studies, we assessed the impact of dementia on blame and forgiveness. Study 1 compared the ways in which young adults, older adults, and older adults with dementia cognitively integrated two factors. Study 2 assessed the number of different factors that older adults with dementia were able to integrate during these moral judgments.MethodThe participants recorded their moral judgements in a blame task and in a forgiveness task. In study 1, the two questionnaires contained scenarios built from the combination of two factors. In study 2, the participants were confronted with the same tasks under three different conditions with scenarios that combined three, four or five factors.ResultsThe data from study 1 showed that the older adults with dementia did not combine the two factors in the same way as young adults did: the combination depended on the type of moral judgment. Study 2 revealed differences in moral judgment between older adults with dementia and adults without dementia in all tasks (i.e. with three, four or five factors combined).ConclusionDementia has an impact on moral judgments. Moral judgment among people with dementia is both task- and condition-dependant.     

Effects of problem presentation durations on arithmetic strategies: a study in young and older adults

Young and older adults were asked toaccomplish a computational estimation task (i.e. provide approximate sums to two-digit addition problems like 38 + 74) under a short versusa longer presentation duration condition. In a choice condition, participants selected the better strategy more often under a long than undera short presentation duration and after an easier than after a harder problem. In the no-choice condition, influence of presentation durationon strategy execution depended on the preceding problems, as participants showed sequence poorer strategy effects. That is, participantswere slower while executing the poorer than while executing the better strategy on current problems following better strategy problems (butequally fast after poorer strategy problems) only under short presentation duration condition. These findings have important theoreticalimplications, as current assumptions of computational models of strategies cannot explain how problem presentation durations influencestrategy selection and strategy execution.     

Response inhibition and avoidance of virtual obstacles during gait in healthy young and older adults

Adjustments of preplanned steps are essential for fall avoidance and require response inhibition. Still, inhibition is rarely tested under conditions resembling daily living. We evaluated the ability of young and older adults to modify ongoing walking movements using a novel precision step inhibition (PSI) task combined with an auditory Stroop task.Healthy young (YA, n = 12) and older (OA, n = 12) adults performed the PSI task at 4 individualized difficulty levels, as a single and dual task (DT). Subjects walked on a treadmill by stepping on virtual stepping stones, unless these changed color during approach, forcing the subjects to avoid them. OA made more failures (40%) on the PSI task than YA (16%), but DT did not affect their performance. In combination with increased rates of omitted Stroop task responses, this indicates a “posture first” strategy. Yet, adding obstacles to the PSI task significantly deteriorated Stroop performance in both groups (the average Stroop composite score decreased by 13% in YA and 27% in OA). Largest deficit of OA was observed in rates of incorrect responses to incongruent Stroop stimuli (OA 35% and YA 12%), which require response inhibition. We concluded that the performance of OA suffered specifically when response inhibition was required.     

Both young and older adults discount suggestions from older adults on a social memory test

In the present study, we examined the impacts of participant age and confederate age on social memory processes. During a collaborative recall phase, young and older adult participants were exposed to the erroneous memory reports of a young or an older adult confederate. On a subsequent individual recall test, young and older adult participants were equally likely to incorporate the confederates’ erroneous suggestions into their memory reports, suggesting that participant age had a minimal effect on social memory processes. However, confederate age did have a marked effect: Young adult participants were less likely to incorporate misleading suggestions from older adult confederates and less likely to report “remembering” items suggested by older adult confederates. Critically, older adult participants were also less likely to incorporate misleading information from fellow older adult confederates. Both young and older adult participants discounted older adult confederates’ contributions to a memory test.     

Effects of mugshot commitment on lineup performance in young and older adults

Two experiments assessed the effects of mugshot commitment on the ability to make a subsequent lineup identification. Young (17–37 years) and older (55–87 years) participants viewed a crime video featuring a younger (20 years) or older (64 years) culprit. Some participants viewed a 50‐photograph culprit‐absent mugbook. Following a 1‐week delay, participants returned to view a culprit present lineup. In Experiment 1, mugbook choosers tended to select their prior selection in the lineup and mugbook nonchoosers tended to reject the lineup. In Experiment 2, mugshot choosers rejected a lineup that did not contain their prior selection. Commitment to a prior selection and commitment to a selection strategy were the cause of the majority of lineup errors. As previously reported, mugshot exposure harms subsequent lineup identification, and this appears to be primarily the result of commitment effects. Copyright © 2008 John Wiley & Sons, Ltd.     

Effects of emotion on item and source memory in young and older adults

Emotional experiences are easier to remember than neutral ones, but whether memory for all aspects of an experience is improved by emotion remains unclear. Some researchers have argued that the influence of emotion on memory is different for item than for source information, whereas others have argued that emotion affects both similarly. Also, whether item and source memory are affected by emotion in older people in the same way as in young people is currently unclear. We examined item and source memory for emotional and neutral materials in young and older adults. Memory for emotional items was superior to memory for neutral items, whereas there was no difference in source memory. Overall, item and source memory were poorer in older people than in young people, but emotion seemed to have a similar effect on both age groups. Although emotional content was remembered better than neutral content, this benefit did not apply to source memory. However, varying the emotionality of the source (i.e., the voice in Experiment 3) improved memory for the source, and this effect was greater in young than in older people. Tone of voice had no effect on item memory in older people, but the effect was variable in the young and may depend on the extent to which the tone of voice moderates the interpretation of the content.     

Development of and change in cognitive control: A comparison of children, young adults, and older adults

Cognitive control involves adjustments in behavior to conflicting information, develops throughout childhood, and declines in aging. Accordingly, developmental and age-related changes in cognitive control and response-conflict detection were assessed in a response-compatibility task. We recorded performance measures, pre-response time (pre-RT) activity and medial frontal negativity (MFN)—sequentially occurring, putative event-related potential (ERP) indexes, respectively, of cognitive control and response-conflict detection. When response conflict reached the highest levels by requiring incompatible responses on posterror trials, children and older adults showed the greatest performance decrements. ERPs indicated that young adults implemented control (pre-RT) and detected the increased conflict (MFN) only when that conflict was at the highest levels, whereas children and older adults did so at lower levels (e.g., posterror, compatible responses). Consequently, the developmental and age-related performance decrements observed here may be due to the undifferentiated and inefficient manner in which children and older adults recruited the processes associated with both cognitive control and response-conflict detection.     

Effects of execution duration on within-item strategy switching in young and older adults

This study aimed at determining whether previously found age-related differences in within-item strategy switching is modulated by duration of engagement in initial strategy execution. In a computational estimation task, young and older adults had to find estimates to arithmetic problems like 37×64 while either rounding down (i.e., 30×60) or rounding up (i.e., 40×70) both operands to the closest decades. Participants were asked to execute a cued strategy for different durations (i.e., 1, 2, or 3 s), before deciding whether the cued strategy was the best strategy and to switch to the best strategy if the cued strategy was not the best. The main findings revealed that (1) young and older adults were able to switch strategies, especially when they started to execute poorer strategy on a given item; (2) older adults switched strategy less often than young adults, and (3) both young and older participants switched strategy less frequently for long than for short durations. These findings suggest that to be able to switch strategy within item, participants should not be too much engaged in execution of the initially selected strategy, and that duration of engagement in initial strategy execution does not modulate age-related differences in within-item strategy execution.     

Speech-processing capacity in young and older adults: a dual-task study

Adult age differences in processing speech were examined with a dual-task paradigm. Subjects listened to spoken passages for later recall while performing a concurrent reaction time task intended to index cognitive capacity usage on the speech memory task. Age differences in secondary task decision latencies were eliminated when subgroups of young and older subjects were matched on working memory span. These findings are interpreted as showing that an age-related reduction in working memory efficiency contributes to age differences in processing discourse for memory.     

Effects of repetition on associative recognition in young and older adults: item and associative strengthening

Young and older adults studied word pairs and later discriminated studied pairs from various types of foils including recombined word-pairs and foil pairs containing one or two previously unstudied words. We manipulated how many times a specific word pair was repeated (1 or 5) and how many different words were associated with a given word (1 or 5) to tease apart the effects of item familiarity from recollection of the association. Rather than making simple old/new judgments, subjects chose one of five responses: (a) Old-Old (original), (b) Old-Old (rearranged), (c) Old-New, (d) New-Old, (e) New-New. Veridical recollection was impaired in old age in all memory conditions. There was evidence for a higher rate of false recollection of rearranged pairs following exact repetition of study pairs in older but not younger adults. In contrast, older adults were not more susceptible to interference than young adults when one or both words of the pair had multiple competing associates. Older adults were just as able as young adults to use item familiarity to recognize which word of a foil was old. This pattern suggests that recollection problems in advanced age are because of a deficit in older adults' formation or retrieval of new associations in memory. A modeling simulation provided good fits to these data and offers a mechanistic explanation based on an age-related reduction of working memory.     

Effects of repetition and response deadline on associative recognition in young and older adults

The present study examined the joint effects of repetition and response deadline on associative recognition in older adults. Young and older adults studied lists of unrelated word pairs, half presented once (weak pairs) and half presented four times (strong pairs). Test lists contained old (intact) pairs, pairs consisting of old words that had been studied with other partners (rearranged lures), and unstudied pairs (new lures), and participants were asked to respond "old" only to intact pairs. In Experiment 1, participants were tested with both short and long deadlines. In Experiment 2, the tests were unpaced. In both experiments, repetition increased hit rates for young and older adults. Young adults tested with a long deadline showed reduced (Experiment 1) or invariant (Experiment 2) false alarms to rearranged lures when word pairs were studied more often. Young adults tested with a short deadline and older adults tested under all conditions had increased false alarm rates forstrong rearranged pairs. Implications of these results for theories of associative recognition and cognitive aging are explored.     

Effects of repetition and response deadline on item recognition in young and older adults

In the present study, we examined the joint effects of aging, repetition, and response deadline in a plurality discrimination task. Young and older adults studied lists of unrelated singular and plural nouns, with half presented once (weak items) and half presented five times (strong items). Test lists contained old (same) nouns, plurality-reversed nouns (changed lures), and unstudied nouns (new lures), and the participants were asked to respond old only to same items. In Experiment 1, the participants were tested with both short and long deadlines. In Experiment 2, the tests were unpaced. In both experiments, repetition increased hit rates for young and older adults. Young adults tested with a long deadline or no deadline showed invariant (Experiment 1) or reduced (Experiment 2) false alarms to changed lures when the nouns were studied more often. Young adults tested with a short deadline and older adults tested with both long and short deadlines had increased false alarm rates for strong changed lures; without time pressure to respond, older adults did not have a significant increase in false alarms for changed lures. Implications of these results for theories of cognitive aging are explored.     

Effects of dichotic listening on gait domains of healthy older adults during dual-tasking: An exploratory observational study

BackgroundIdentification of the cognitive mechanisms behind gait changes in aging is a prime endeavor in gerontology and geriatrics. For this reason, we have implemented a new dual-task paradigm where an auditory attentional task is performed during over-ground walking. Dichotic listening assesses spontaneous attention and voluntary attention directed to right and left-ear. The uniqueness of dichotic listening relies on its requirements that vary in difficulty and recruitment of resources from whole brain to one brain hemisphere. When used in dual-tasking, asymmetric effects on certain gait parameters have been reported.ObjectivesThe present study aims to acquire a more global understanding on how dichotic listening affects gait domains. Specifically, we aimed to understand how spontaneous vs lateralized auditory attention altered the Principal Component Analysis (PCA) structure of gait in healthy older adults.MethodsSeventy-eight healthy older adults (mean age: 71.1 years; 44 women and 34 men) underwent the Bergen dichotic listening test while walking. As this study only focuses on the effects of the cognitive task on gait, only dual-task costs for gait were calculated and entered into the PCA analyses. We explored the PCA structure for the effects on bilateral gait parameters (i.e., both limbs together) as well as on lateralized gait parameters (i.e, separate parameters by limb). We first established gait domains during single-task walking. Then, dual-task cost scores for gait were entered in a series of PCAs.ResultsResults from the PCAs for bilateral gait parameters showed limited alterations on gait structure. In contrast, PCAs for lateralized data demonstrated modifications of the gait structure during dichotic listening. The PCAs corresponding for all dichotic listening conditions showed different factor solutions ranging between 4 and 6 factors that explained between 73.8% to 80% of the total variance. As a whole, all conditions had an impact on “pace”, “pace variability” and “base of support variability” domains. In the spontaneous attention condition, a six-factor solution explaining 78.3% of the variance showed asymmetrical disruptions on the PCA structure. When attention was focused to right-ear, a five-factor solution explaining 89% of the variance and similar to baseline was found. When attention was directed to left-ear, a four-factor solution explaining 73.8% of the variance was found with symmetrical impact on all factors.ConclusionsThese findings demonstrate for the first time that specific facets of attentional control affects gait domains both symmetrically and asymmetrically in healthy older adults.     

Autobiographical remembering and hypermnesia: a comparison of older and younger adults

This study examined age differences in autobiographical memory and extended findings concerning hypermnesia in laboratory tasks to a real world event, the announcement of the verdict in the O. J. Simpson murder trial. Older and younger adults repeatedly recalled the event in a single session. Interviews were coded for amount and type of accurate information and for errors. The age groups did not differ in ability to recall the gist of the event or in the number of errors made. Younger adults were better at remembering when the event had occurred. Both age groups showed hypermnesia. The results are discussed in terms of the importance of autobiographical memory across the life span and the phenomenon of hypermnesia in everyday memory.     

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.     

Effects of induced sad mood on facial emotion perception in young and older adults

Older adults perceive less intense negative emotion in facial expressions compared to younger counterparts. Prior research has also demonstrated that mood alters facial emotion perception. Nevertheless, there is little evidence which evaluates the interactive effects of age and mood on emotion perception. This study investigated the effects of sad mood on younger and older adults’ perception of emotional and neutral faces. Participants rated the intensity of stimuli while listening to sad music and in silence. Measures of mood were administered. Younger and older participants’ rated sad faces as displaying stronger sadness when they experienced sad mood. While younger participants showed no influence of sad mood on happiness ratings of happy faces, older adults rated happy faces as conveying less happiness when they experienced sad mood. This study demonstrates how emotion perception can change when a controlled mood induction procedure is applied to alter mood in young and older participants.     

Assessment of anxiety in older adults: a community-based survey and comparison with younger adults

The reliability and validity of existing anxiety self-report scales in elderly adults has not been adequately established, and the phenomenology of anxiety in older adults is largely unknown. In the present study, three anxiety scales and measures of depression and somatization were used to compare symptoms between older (n = 84, mean age = 75.3) and younger (n = 48, mean age = 40.3) community-dwelling adults. Results showed that the anxiety scales demonstrated good internal consistency in both age groups, although the reliabilities of the Fear Questionnaire subscales ranged from poor to good. Convergent and divergent validity were found to be variable in the older group, but this may reflect differences in anxiety as it occurs in older persons rather than psychometric problems. Anxiety symptoms did not vary with age, and levels of anxiety also remained constant. However, gender differences were found only within the older age group, with women reporting more anxiety than men. Findings are discussed with respect to current conceptualizations of anxiety in older people, as well as implications for future research.     

Sustained-attention capacity in young and older adults

The sustained-attention capacity of young (21-29 years) and older (65-78 years) adults was examined using a high-event rate digit-discrimination vigilance task presented at three levels of stimulus degradation. Increased stimulus degradation led to a reduction in the hit rate and to a greater decline in hit rate over blocks (increased vigilance decrement). Sensitivity (d') declined over blocks only at the highest level of stimulus degradation. Older adults had a lower hit rate and showed greater vigilance decrement than young adults, particularly when stimuli were highly degraded. However, both age groups showed the same pattern of stability in sensitivity when stimulus degradation was moderate, and sensitivity decrement over time when stimulus degradation was high. The results suggest that the process of sustained allocation of capacity--as reflected in temporal changes in sensitivity--operates similarly in young and older adults.     

False memories for a robbery in young and older adults

The aim of the present study was to analyse memory performance in young and older adults based on a robbery scenario. The study examined free recall and the recognition of actions, people and details, as well as the Remember/Know/Guess judgements that accompanied recognition. Recognition was evaluated both immediately and 1 week later, although performance was not affected by the retention interval. In the free recall task, the older adults remembered less information than the younger adults but we found no differences between the two with regard to errors. Participants accepted more false actions, thus achieving higher recognition accuracy for people and details. They also categorized false alarms for actions more often as remember than as know or guess judgements. This pattern of results was more pronounced in the older adults, suggesting that aging is an important factor in false memories for events. Copyright © 2008 John Wiley & Sons, Ltd.