Age-related Differences In Effects Research Articles

Are There Age-Related Differences in Effects of Positive and Negative Emotions in Arithmetic?

We investigated effects of emotions on arithmetic problem-solving and age-related differences in these effects. Young and older adults verified addition problems displayed superimposed on emotionally negative, positive, or neutral pictures. Participants obtained poorer performance in emotion than in neutral conditions, with stronger interference by negative than positive emotions. Also, participants were more impaired by negative emotions while solving true problems than false problems, whereas they were influenced by positive emotions similarly on true and false problems. Interestingly, effects of both positive and negative emotions were comparable in young and older adults. These findings have important implications for further understanding how negative and positive emotions influence arithmetic problem-solving.

Gaze cueing in older and younger adults is elicited by a social robot seen from the back

The ability to follow the gaze of others deteriorates with age. This decline is typically tested with gaze cueing tasks, in which the time it takes to respond to targets on a screen is faster when they are preceded by a facial cue looking in the direction of the target (i.e., gaze cueing effect). It is unclear whether age-related differences in this effect occur with gaze cues other than the eyes, such as head orientation, and how these vary in function of the cue-target timing. Based on the perceived usefulness of social robots to assist older adults, we asked older and young adults to perform a gaze cueing task with the head of a NAO robot as the central cue. Crucially, the head was viewed from the back, and so its eye gaze was conveyed. In a control condition, the head was static and faced away from the participant. The stimulus onset asynchrony (SOA) between cue and target was 340 ms or 1000 ms. Both age groups showed a gaze cueing effect at both SOAs. Older participants showed a reduced facilitation effect (i.e., faster on congruent gazing trials than on neutral trials) at the 340-ms SOA compared to the 1000-ms SOA, and no differences between incongruent trials and neutral trials at the 340-ms SOA. Our results show that a robot with non-visible eyes can elicit gaze cueing effects. Age-related differences in the other effects are discussed regarding differences in processing time.

Age-related differences in effects of non-driving related tasks on takeover performance in automated driving

Introduction: During SAE level 3 automated driving, the driver’s role changes from active driver to fallback-ready driver. Drowsiness is one of the factors that may degrade driver’s takeover performance. This study aimed to investigate effects of non-driving related tasks (NDRTs) to counter driver’s drowsiness with a Level 3 system activated and to improve successive takeover performance in a critical situation. A special focus was placed on age-related differences in the effects. Method: Participants of three age groups (younger, middle-aged, older) drove the Level 3 system implemented in a high-fidelity motion-based driving simulator for about 30 min under three experiment conditions: without NDRT, while watching a video clip, and while switching between watching a video clip and playing a game. The Karolinska Sleepiness Scale and eyeblink duration measured driver drowsiness. At the end of the drive, the drivers had to take over control of the vehicle and manually change the lane to avoid a collision. Reaction time and steering angle variability were measured to evaluate the two aspects of driving performance. Results: For younger drivers, both single and multiple NDRT engagements countered the development of driver drowsiness during automated driving, and their takeover performance was equivalent to or better than their performance without NDRT engagement. For older drivers, NDRT engagement did not affect the development of drowsiness but degraded takeover performance especially under the multiple NDRT engagement condition. The results for middle-aged drivers fell at an intermediate level between those for younger and older drivers. Practical Applications: The present findings do not support general recommendations of NDRT engagement to counter drowsiness during automated driving. This study is especially relevant to the automotive industry’s search for options that will ensure the safest interfaces between human drivers and automation systems.

Age-related differences in effectiveness of item restudy choices: the role of value

ABSTRACTWe examined the effect of value on effectiveness of restudy choices in younger and older adults by using an honor or dishonor procedure. In the honor condition, participants restudied the half of the items that they selected for restudy. In the dishonor condition, participants restudied the half of the items that they did not select for restudy. The results showed that younger adults restudied more low-value (1-point) items that they had rated as least-well learned, while older adults restudied more high-value (5-point) items. For younger adults, 1-point-value item performance in the honor condition was reliably higher than it was in the dishonor condition. For older adults, 5-point-value items performance in the honor condition was reliably higher than it was in the dishonor condition. These results suggest that older adults can exert effective restudy choices like younger adults when item value is manipulated.

A single exposure to morphine induces long‐lasting sensitization: age‐related differences in mice

Given evidence for age‐related differences in effects of drugs of abuse, surprisingly few studies have explored effects of opioids in adolescents (versus adults). This study compared locomotor sensitization in adolescent and adult mice after a single exposure to morphine.Adolescent (postnatal day 29) and adult male C57BL/6J mice were treated with saline or morphine (1–100 mg/kg, i.p.) (session 1), and morphine (10 mg/kg)‐induced locomotion was assessed 3–36 days later (session 2). Morphine during session 1 dose‐dependently enhanced the locomotor‐stimulating effects of 10 mg/kg morphine during session 2. The minimum significant dose was 3.2 mg/kg in adults and 32 mg/kg in adolescents, and the maximal enhancement was 200% in adults and 150% in adolescents. Irrespective of age, the enhancement increased with the length of the intersession interval, attained a maximum at 1 week, and remained unchanged at 2 and 5 weeks. In adults, but not in adolescents, the enhancement was largest when both sessions were conducted in the same environment.These results show that a single exposure to morphine induces dose‐, delay‐, and context dependent sensitization in adults. In adolescents, morphine induces sensitization less potently, less efficaciously, and less dependent on the context than in adults, but its sensitizing effects are as long‐lasting as in adults, and last into adulthood.Supported by DA23261

Sensitization of morphine‐induced motor stimulation: age‐related differences in mice

Given evidence for age‐related differences in effects of drugs of abuse, surprisingly few studies have explored effects of opioids in adolescents (versus adults). This study compared sensitization of morphine‐induced locomotion in adolescent and adult mice.Male C57BL/6J mice were treated with saline or morphine (10–100 mg/kg, i.p.) once per day for 4 days, and morphine (3.2–56 mg/kg)‐induced locomotion was assessed 3 days or 5 weeks later. Three days after repeated saline, morphine increased locomotion more in adolescents than in adults. Repeated morphine (minimum effective dose: 17.8 mg/kg) enhanced morphine‐induced locomotion to a similar extent in each age group (1.6 – 1.9 fold). This enhancement was still evident 5 weeks later, when the adolescents had become adult, but was smaller (1.4‐fold) and occurred at a higher dose (56 mg/kg). In animals treated repeatedly with morphine as adults, enhancing effects were no longer apparent 5 weeks later.Repeated administration of morphine produced similar short‐term enhancement of its motor stimulating effects in all age groups, but evidence for long‐term enhancement was obtained only in adolescents. These findings suggest that compared with adults, adolescents are more sensitive not only to the acute locomotor stimulating effects of morphine, but also to its long‐lasting locomotor sensitizing effects.Supported by DA23261

Online Grammaticality Judgments in French Young and Older Adults

Background/Study Context: A goal of language and aging research is to determine the nature of change in language-processing skills. In this study the authors examine the role of age and use of cues (e.g., word order, verbal agreement, sentence structure) on online sentence processing. Methods: French young and older adults were asked to detect grammatical violations in sentences as quickly as possible. Detection times were analyzed as a function of participants’ age and sentence characteristics (i.e., violation type, span, and position). Results: Above and beyond main effects of participant's age and linguistic features, results showed age-related differences in effects of linguistic cues on sentence processing and important individual differences during aging in hierarchies of cue strength. Conclusion: Young and older adults use similar linguistic cues in the online process, but loss of cognitive resources with age shows a cost of cue use and a greater use of context.

Age-specific differences in binding of heparin to plasma proteins.

Clinically significant age-related differences in the anticoagulation effect of heparin have previously been established in vitro as well as in different clinical settings in vivo. These differences were hypothesized to be due to the age-specific differences in binding of heparin to plasma proteins. The aim of this project was to investigate global age-related differences in heparin binding to plasma proteins. Heparin-binding proteins were identified by incubating heparin-coated magnetic beads with plasma samples from neonates, children and adults, and purifying the proteins that were bound to the beads in this reaction system. These results provide the first preliminary evidence of age-related differences in the total number and concentration of proteins bound to heparin. The results also suggest, for the first time, that there are age-related differences of heparin binding to antithrombin and thrombin. The results of this study, although preliminary, support and contribute to the explanation of the mechanism of age-related differences in the effect of heparin observed previously in vitro and in vivo.

Increased cortisol levels in cognitively challenging situations are beneficial in young but not older subjects

Adaptation to stressful situations changes with increasing age. This is also reflected in age-related differences in effects of acute stress on, e.g., episodic memory. Less is known about age-related differences of the cognitive effects of individual stress responses to challenging situations. To investigate the influence of the individual cortisol response (as a marker for the individual stress level) on behavioral and neural measures during a challenging memory paradigm. Twenty young and 12 older subjects were scanned using functional magnetic resonance imaging during encoding and retrieval of spatial contextual information. Salivary cortisol levels were measured before and after scanning. A multiple regression analysis of behavioral data showed an interaction effect of age and cortisol response on memory for the items and their spatial context during retrieval due to increased accuracy with increasing cortisol responses in young compared to old subjects. During encoding, this was reflected in a positive effect of the cortisol response on prefrontal activity in young but not in older subjects. During retrieval, there was a negative effect of the cortisol response on brain activity in the hippocampus and prefrontal regions in older but not in young subjects. The data suggest an increased efficiency to encode items and their context with increasing cortisol responses in young subjects, and a decreased efficiency to retrieve information with increasing cortisol responses in older subjects. We conclude that neuroendocrine responses are differentially associated with behavioral and neural measures in cognitively challenging situations in young and older volunteers.

The in vitro anticoagulant effects of Danaparoid, Fondaparinux, and Lepirudin in children compared to adults

Introduction Major physiological differences in the coagulation system of children compared to that of adults are well documented. We have previously investigated the age-related differences in response to Unfractionated Heparin (UFH). However, the impact of developmental haemostasis on more recent anticoagulant drugs is unknown. A number of these drugs are approved for use in specific indications in adults and none are approved for use in children. This study aimed to determine whether age-related differences in effect and impact on monitoring tests exist in vitro for danaparoid, fondaparinux and lepirudin. Materials and Methods Plasma samples were obtained from healthy children and pooled into age-specific pools, in order to obtain sufficient quantity of plasma required for the analysis of the three drugs. Each age-specific pool was spiked with different concentrations of danaparoid, fondaparinux and lepirudin and response was measured using standard techniques. All experiments were repeated using three separate plasma pools. The effect of each drug in children's plasma was compared to the effect in the respective adult plasma pool. Results Age-related differences in effect on thrombin potential and monitoring tests were observed only with the drug lepirudin. Specifically, APTT for children up to 5 years of age was increased compared to adults; all children had lower ECT results compared to adults; children up to 10 years of age had increased inhibition of ETP as compared to adults. Conclusions This study confirms age-related differences in response to anticoagulants with predominant anti-IIa effect and highlights the need for further research into this area.

Changes in drug requirements during growth

Recent studies of familiar neuromuscular-blocking drugs, including pancuronium, d-tubocurarine, suxamethonium and alcuronium, demonstrate interesting age-related differences in effect. These effects have also been observed in recent studies of a new drug, propofol. With all these drugs, the age-related differences in effect might be explained by differences in the rate of delivery of a bolus to the site of action. Recent studies of the narcotics alfentanil and morphine found differences in pharmacokinetics with age that could affect the rate of recovery. In addition, tolerance has been shown to develop in infants receiving fentanyl over the course of several days.

Aging alters the force-frequency relationship and toxicity of oxidative stress in rabbit heart

Adult (6 months) and senescent (> 5 years) rabbit atria were studied under conditions known to increase cytoplasmic calcium (increased frequency of contraction and oxidative stress). At a contraction frequency of 1/sec, cardiac relaxation (90% relaxation time) was similar in senescent and adult atria but at a frequency of 2 or 3/sec, relaxation was significantly slower in senescent preparations (P < 0.05). Additional experiments indicated that H 2O 2 (500 μM), a powerful oxidant, increased resting force and decreased developed force (DF) much more rapidly in senescent than adult atria; the maximum decrease in DF, however, was less in senescent preparations (adult = 81 ± 6% and senescent = 42 ± 27% of pre-H 2O 2 values; P < 0.05). Age-related differences in effects of H 2O 2 did not result simply from a decreased ability of senescent hearts to detoxify an oxidative stress by the glutathione pathway. Both basal glutathione (GSH) concentrations and the H 2O 2-mediated decreases in GSH were similar in adult and senescent ventricular preparations, as were activities of glutathione peroxidase and glutathione reductase. These observations suggest that interventions known to increase cytoplasmic calcium can amplify age-related impairments of cardiac relaxation through mechanisms that may be independent of the glutathione pathway.

Age-related differences in effect of exercise training on cardiac muscle function in rats.

To test the hypothesis that age may alter the effect of exercise training on myocardial function, we trained young adult (4-5 mo at study initiation) and old (21 mo at initiation) male Fischer 344 rats to run on a rodent treadmill 5 days/wk for 4.5 mo and compared their myocardial function with that of age-matched sedentary controls. Right ventricular papillary muscles were isolated from the young adult and aged animals and stimulated at the length at which developed isometric tension was maximal to contract isometrically at 12/min, bathed in oxygenated modified Krebs solution, and studied at 28 degrees, 32 degrees, 35 degrees, and 38 degrees C. In the absence of cardiac hypertrophy, exercise training significantly reversed the age-related prolongation of isometric contraction duration in the senescent rat (P less than 0.001). However, exercise training prolonged contraction duration in the young adult rat (P less than 0.05). The relaxation phase was more sensitive than the contraction phase to changes in temperature, especially in the aged rat (P less than 0.02). The ratio of developed tension to time-to-peak tension of the isometric twitch was not affected by exercise training. Because exercise training affects cardiac function in opposite directions from young adulthood to senescence, caution is advised in extrapolating results from exercise studies in young adult rats to populations of older animals.