Group Of Healthy Older Adults Research Articles

AGE-RELATED EFFECTS OF A COGNITIVE TASK ON FRONTAL PLANE STABILITY DURING NARROW-BASE WALKING.

Purpose/Hypothesis: Age-related changes in frontal plane stability during gait are associated with impaired balance and increased fall risk in older adults. Clinically, tandem and narrowbase walking are used to assess dynamic gait stability. Adding a cognitive task to narrow-base walking (i.e. dual tasking) may further challenge stability, allowing identification of early balance deficits not detected under single task conditions. The purpose of this study is to examine age-related effects of a cognitive task on frontal plane stability during narrow-base walking in a population of healthy older adults. Subjects: Thirty subjects categorized by age: <65, 65–74, and 75 years, with 10 subjects per group. Materials/Methods: We examined spatiotemporal and center of mass (COM) parameters during narrow-base walking with and without a cognitive task. Statistical analyses included repeated measures ANOVA's (3 age groups x 2 task conditions). Results: The percent of step errors (i.e. steps outside the narrow-base corridor) did not differ significantly between groups (p=0.29) and was not affected by the performance of a secondary task (p=0.80). On average, about 16% of the steps were outside the narrow-base corridor. Average stride velocity (p<0.001) and step length (p<0.001) decreased with age, while mediolateral COM peak velocity (p<0.001) and displacement (p<0.05) increased. Addition of a cognitive task decreased stride velocity (p<0.001) and step length (p<0.05) for all age groups, but did not affect COM characteristics. Conclusions: Age-related changes in both velocity and frontal plane stability are evident during narrow-base gait. The addition of a secondary task affected stride velocity and stride length but did not affect mediolateral COM control in this group of healthy older adults. Clinical Relevance: The use of a cognitive task during balance and gait activities can help to identify individuals with increased fall risk. Further research is needed to determine if changes in narrow-base walking with versus without a secondary task can be used to predict future falls in older adults. If so, narrow-base walking under single and dual task conditions may be useful in identifying older adults with preclinical instability.

Revealing Language Deficits Following Stroke: The Cost of Doing Two Things at Once

ABSTRACT The costs of doing two things were assessed for a group of healthy older adults and older adults who were tested at least 6 months after a stroke. A baseline language sample was compared to language samples collected while the participants were performing concurrent motor tasks or selective ignoring tasks. Whereas the healthy older adults showed few costs due to the concurrent task demands, the language samples from the stroke survivors were disrupted by the demands of doing two things at once. The dual task measures reveal long-lasting effects of strokes that were not evident when stroke survivors were assessed using standard clinical tools.

Age-related change in neural processing of time-dependent stimulus features

Aging is associated with changes in automatic processing of task-irrelevant stimuli, and this may lead to functional disturbances including repeated orienting to nonnovel events and distraction from task. The effect of age on automatic processing of time-dependent stimulus features was investigated by measurement of the auditory mismatch negativity (MMN) in younger (18–23) and older (55–85) adults. Amplitude of MMN recorded during a paradigm involving low-probability deviation in interstimulus interval (from 500 ms to 250 ms) was found to be reduced in the older group at fronto-central sites. This effect was paralleled by, and correlated to, decreased sensory gating efficiency for component N1 recorded during a separate paradigm involving alternate presentation of auditory stimuli at long (9 s) and short (0.5 s) interstimulus intervals. Further, MMN amplitude was correlated to behavioral performance on a small subset of neuropsychological tests, including the Rey Auditory Verbal Learning Test, within a group of healthy older adults. The results support the hypothesis that aging is associated with declines in automatic processing of time-dependent stimulus features, and this is related to cognitive function. These conclusions are considered in the context of age-related declines in prefrontal cortex function and associated increases in susceptibility to task-irrelevant stimuli.

Can we trust depression screening instruments in healthy ‘old‐old’ adults?

Despite a growing understanding of late-life depression, few studies focus on the old-old, those 75 years and over. We wished to characterize depressive symptoms and determine the accuracy of two common screening instruments for major and minor depression in a population of old-old retirees. Participants lived independently in one of two Continuing Care Retirement Communities and volunteered for an in-home interview about cancer screening attitudes. As part of this baseline interview, they were screened with the Geriatric Depression Scale (GDS) and the Center for Epidemiologic Studies-Depression (CES-D) scale. Those agreeing to a second interview received an evaluation using the Structured Clinical Interview for DSM-IV (SCID-IV), performed by a geriatric psychiatrist within two weeks of the initial interview. In an educated and cognitively intact group of retirees averaging 80 years of age, the GDS and CES-D performed poorly using standard cutpoints in detecting both major (sensitivity 60% for both) and minor (sensitivity 33% and 50%, respectively) depression. One in five participants had significant depression as confirmed by SCID-IV evaluation. Twelve percent had major depression and 7% had minor depression. Most participants had their first episode of either after age 60. Contrary to most studies evaluating the GDS and CES-D for accuracy in detecting late-life depression, these instruments at standard cutpoints performed poorly in this group of healthy older adults. The healthy old-old may require novel screening interventions to detect clinically significant depression.

Sensory Training Effects on Obstacle Avoidance in Healthy Older Adults

The purpose of this study was to examine the effectiveness of a five-day balance training program on obstacle avoidance measures in a group of healthy older adults. A 2 × 3 repeated measures MANOVA revealed no significant differences between three groups of older adult participants. A follow-up paired t-test revealed a significant difference between the control group and the experimental and walking control groups for pre- and post-tests. These results suggest that a five-day program is ineffective for improving measures of toe clearance, heel clearance, horizontal shear, and gait velocity, but may be beneficial in delaying a loss in obstacle crossing speed in healthy older adults.

VARIABILITY IN KINEMATIC MEASURES OF GAIT IN HEALTHY OLDER ADULTS

Age-related changes in the kinematics of stepping in healthy older adults often alter performance. As falls are often the result of tripping over an obstacle, a better understanding of the kinematic measures associated with obstacle avoidance is needed. PURPOSE To examine within-subject variability in kinematic measures of obstacle avoidance in a group of healthy older adults. Avoidance measures included toe clearance, heel clearance, obstacle crossing speed, horizontal shear, and gait velocity. METHODS Thirty healthy older adult participants involved in a larger investigation examining the effects of an indirect dynamic multi-sensory training protocol were examined. Pre- and post-test measurements were obtained for toe clearance, heel clearance, obstacle crossing speed, horizontal shear, and gait velocity. RESULTS Descriptive statistical analysis revealed higher within-subject variability for measures of toe clearance (M 4.26 cm. +/− SD 2.63 cm), heel clearance (M 5.98 cm. +/− SD 2.80 cm.), and horizontal shear (M 109.41 N +/− SD 40.89 N) when compared to the variability for measures of obstacle crossing speed (M .428 m/sec.+/− SD .094 m/sec.) and gait velocity (M .892 m/sec. +/− SD .185 m/sec.). DISCUSSION Results suggest that there is significant variability in kinematic measures associated with obstacle avoidance in healthy older adults. Variability in obstacle avoidance strategies in older adults may account for increases in trips and stumbles and may make group generalizations about both performance and research difficult. These results indicate that further examinations designed to assess functional measures associated with stepping and gait need to account for these large variations in performance and previous research needs to be re-examined.

Sit-to-Stand Performance of Older Adults following Strength Training

A group of healthy older adults completed an 8-week resistance-training program. For 38 participants (14 men, 24 women; ages 60–90 years; M mass = 73.2 kg, SD = 12.3; M height = 1.65 m, SD = 0.08), pre- and postprogram sit-to-stand performance was analyzed (60 Hz video) focusing on center of mass kinematics surrounding transition. Significant changes were attributed to improved strength. Peak forward, downward, and upward velocities increased (16, 59, and 26%, respectively), and relative transition time was delayed 27%. These behaviors were more similar to those of healthy younger adults. Results also indicated strategy changes. Participants exploited their improved strength, forming a distinctive movement pattern emphasizing stability followed by a brisk rise. These adaptations represent meaningfully improved function in an important daily living activity.

Evaluation of Practice Effects in Language and Spatial Processing Test Performance

Recent research demonstrates that practice effects are attenuated through the administration of alternate-form memory tests. However, little is known about the degree of practice that can be expected when alternate forms of nonmemory tests are administered repeatedly. Two groups of healthy older adults were assigned to either a same- or alternate-forms condition. Participants completing the same forms of a confrontation naming task improved significantly over 4 testing sessions. On verbal fluency, participant performance significantly improved when completing only alternate forms. No significant practice effects were observed on tests of spatial processing. Practice effects caused by item-specific practice may be reduced via alternate test forms. However, similar reductions will be less apparent when practice effects are the result of test-specific practice.

Evaluation of Practice Effects in Language and Spatial Processing Test Performance

Recent research demonstrates that practice effects are attenuated through the administration of alternate-form memory tests. However, little is known about the degree of practice that can be expected when alternate forms of nonmemory tests are administered repeatedly. Two groups of healthy older adults were assigned to either a same- or alternate-forms condition. Participants completing the same forms of a confrontation naming task improved significantly over 4 testing sessions. On verbal fluency, participant performance significantly improved when completing only alternate forms. No significant practice effects were observed on tests of spatial processing. Practice effects caused by item-specific practice may be reduced via alternate test forms. However, similar reductions will be less apparent when practice effects are the result of test-specific practice.

The association of hormone replacement therapy with experimental pain responses in postmenopausal women

Considerable experimental research suggests that ovarian hormones can influence pain perception, and recent epidemiologic and clinical research suggests that exogenous hormone use may influence the prevalence and severity of clinical pain among women. However, to date no studies have examined the influence of hormone replacement therapy (HRT) on experimental pain responses and recent pain complaints among postmenopausal women. In this study, self-reported recent pain and general health were obtained, and thermal pain responses were assessed in three groups of healthy older adults: (1) women on HRT, (2) women not on HRT (No-HRT), and (3) men. Results indicated no group differences in recent pain complaints or self-reported health, but differences emerged for measures of thermal pain perception. Specifically, HRT women showed lower pain thresholds and tolerances than No-HRT women and men, and the latter two groups did not differ from each other. The potential explanations and limitations of the observed findings are discussed.

Oral control and body dissatisfaction in older adults: a note of caution

Responses of 99 older adults (mean age 75.5 years) on the EAT-26 oral control subscale and the body dissatisfaction subscale of the Eating Disorders Inventory were examined in 29 congestive heart failure (CHF) patients who had lost a mean 8.5 kg in the preceding 12 months and in 21 CHF patients of stable weight and two groups of healthy older adults with no known weight loss. Whilst significant group differences on oral control were found (p<0.001) item analysis showed that 3/7 items correlated negatively with the subscale total. Endorsement of ‘oral control’ items did not necessarily denote an ‘eating disordered attitude’. Similarly item analysis of ‘body dissatisfaction’ totals showed a dissociation between general body dissatisfaction and ‘feeling too fat’. Caution is needed in interpreting eating attitude scales with older adults, however ‘eating disorders’ research should widen its focus to investigate groups other than the young women on whom most scales were standardized. Copyright © 2000 John Wiley & Sons, Ltd and Eating Disorders Association.

Maintenance of balance, gait patterns, and obstacle clearance in Alzheimer's disease

Patients with cognitive impairment, particularly as a result of Alzheimer's disease (AD), are at increased risk for falls, but it is unclear how, or if, they differ from normal adults in their balance, gait, or ability to clear an obstacle in their path. Using an optoelectronic camera system, we compared body motions and force output at the feet in patients with probable AD (n = 17) with those in healthy older adults (n = 15) while they stood on a force plate or on a beam attached to the force plate that was either stationary or accelerating. Using the same camera system and comparing this AD group with another group of healthy older adults (n = 24), we observed the AD patients during normal walking and while clearing 25- and 152-mm-high obstacles. None of the AD patients had extrapyramidal signs or musculoskeletal impairments. Compared with healthy older adults, normal walking speed was significantly slower in the AD group (p < 0.0001). While clearing either obstacle, the AD patients were significantly slower in their approach (p < 0.0001) and crossing (p < 0.0001) speeds and landed closer to the obstacle after having crossed it (p < 0.02). Moreover, the percent of trials in which a subject made contact with an obstacle was significantly higher in patients with AD (p < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Executive functioning as a mediator of the relationship between age and episodic memory in healthy aging

Abstract The extent to which age-related differences in executive functioning account for age-related differences in recall from episodic memory was examined in a group of healthy older adults. Fifty-one subjects between the ages of 60 and 91 years were given tests of general cognitive abilities, episodic memory, and executive functioning. A mediational model was proposed with executive functioning as the mediator of the relationship between age and delayed recall. Consistent with this model, regression analyses indicated that, when considered alone, age was a significant predictor of recall (p <.001); however, age was not a significant predictor of recall when the effect of executive functioning was partialled out of the equation (p=.37). Furthermore, the unique contribution of executive functioning accounted for 36% of the variance in recall performance. A significant portion of age-related differences in episodic memory recall, therefore, may be due to age-related differences in the executive skills re...

Myringoplasty for the anterior perforation: Experience with the Kerr flap : Sharp J.F.; Terzis T.F.; Robinson J.J. Laryngol. Otol. (1992) 106/1 (14–16)

The present study investigates behavioral and electrophysiological auditory and cognitive-related plasticity in three groups of healthy older adults (60–77 years). Group 1 was moderately hearing-impaired, experienced hearing aid users, and fitted with new hearing aids using non-linear frequency compression (NLFC on); Group 2, also moderately hearing-impaired, used the same type of hearing aids but NLFC was switched off during the entire period of study duration (NLFC off); Group 3 represented individuals with age-appropriate hearing (NHO) as controls, who were not different in IQ, gender, or age from Group 1 and 2. At five measurement time points (M1-M5) across three months, a series of active oddball tasks were administered while EEG was recorded. The stimuli comprised syllables consisting of naturally high-pitched fricatives (/sh/, /s/, and /f/), which are hard to distinguish for individuals with presbycusis. By applying a data-driven microstate approach to obtain global field power (GFP) as a measure of processing effort, the modulations of perceptual (P50, N1, P2) and cognitive-related (N2b, P3b) auditory evoked potentials were calculated and subsequently related to behavioral changes (accuracy and reaction time) across time.All groups improved their performance across time, but NHO showed consistently higher accuracy and faster reaction times than the hearing-impaired groups, especially under difficult conditions. Electrophysiological results complemented this finding by demonstrating longer latencies in the P50 and the N1 peak in hearing aid users. Furthermore, the GFP of cognitive-related evoked potentials decreased from M1 to M2 in the NHO group, while a comparable decrease in the hearing-impaired group was only evident at M5. After twelve weeks of hearing aid use of eight hours each day, we found a significantly lower GFP in the P3b of the group with NLFC on as compared to the group with NLFC off.These findings suggest higher processing effort, as evidenced by higher GFP, in hearing-impaired individuals when compared to those with normal hearing, although the hearing-impaired show a decrease of processing effort after repeated stimulus exposure. In addition, our findings indicate that the acclimatization to a new hearing aid algorithm may take several weeks.

Impaired sympathetic nervous system response to cognitive effort in early Alzheimer's disease.

Sympathetic nervous system responses to a cognitive challenge and a physiologic stimulus (upright posture) were compared in 10 patients with early Alzheimer's Disease and a group of healthy older adults. Plasma catecholamine and cardiovascular responses to upright posture were similar in the two groups. However, sympathetic activation during mental effort was impaired in the patient group; this difference did not appear to be attributable to motivational factors. Alzheimer's Disease is associated with a defect in sympathetic nervous system function that is specifically linked to cognitive effort and appears early in the course of the disease.

Memory improvement at different stages of Alzheimer's disease

Three groups of patients with dementia of the Alzheimer type (mildly, moderately and severely demented) and two groups of healthy older adults (73 and 82 yr old) were examined on free and cued recall of subject-performed tasks (SPTs) or verbally presented sentences depicting the same verbal information as the SPTs. Results indicated that all groups examined performed better on SPTs than on the verbal task. In addition, for all groups cuing effects were greater in the SPT task than in the verbal task.