Lack Of Age Differences Research Articles

A Matter of Memory? Age-Invariant Relative Clause Disambiguation and Memory Interference in Older Adults.

Past research suggests that Working Memory plays a role in determining relative clause attachment bias. Disambiguation preferences may further depend on Processing Speed and explicit memory demands in linguistic tasks. Given that Working Memory and Processing Speed decline with age, older adults offer a way of investigating the factors underlying disambiguation preferences. Additionally, older adults might be subject to more severe similarity-based memory interference given their larger vocabularies and slower lexical access. Nevertheless, memory interference and sentence disambiguation have not been combined in studies on older adults before. We used a self-paced reading paradigm under memory load interference conditions. Older (n=30) and Younger (n=35) readers took part in the study online; reading times were recorded and measures of comprehension accuracy and load recall were collected. This setup allowed for the implicit measurement of attachment biases and memory interference effects interactively. Results show that similarity-based interference affected both age groups equally, but was more pronounced in NP2-biased structures, which took participants generally longer to read. Attachment preferences did not differ by group and were unaffected by Working Memory span. However, accuracy on recall prompts was predicted by Working Memory span in both groups. Findings of greater interference in syntactically dispreferred structures support unified processing models where parsing constraints naturally interact. The lack of age differences on our measures further aligns with research finding age-invariant implicit language processing.

The effects of aging and an episodic specificity induction on spontaneous task-unrelated thought.

When voluntarily describing their past or future, older adults typically show a reduction in episodic specificity (e.g., including fewer details reflecting a specific event, time and/or place). However, aging has less impact on other types of tasks that place minimal demands on strategic retrieval such as spontaneous thoughts. In the current study, we investigated age-related differences in the episodic specificity of spontaneous thoughts using experimenter-based coding of thought descriptions. Additionally, we tested whether an episodic specificity induction, which increases episodic detail during deliberate retrieval of events in young and older adults, has the same effect under spontaneous retrieval. Twenty-four younger and 24 healthy older adults performed two counterbalanced sessions including a video, the episodic specificity or control induction, and a vigilance task. In the episodic specificity induction, participants recalled the details of the video while in the control they solved math exercises. The impact of this manipulation on the episodic specificity of spontaneous thoughts was assessed in the subsequent vigilance task, in which participants were randomly stopped to describe their thoughts and classify them as deliberate/spontaneous. We found no differences in episodic specificity between age groups in spontaneous thoughts, supporting the prediction that automatic retrieval attenuates the episodic specificity decrease in aging. The lack of age differences was present regardless of the induction, showing no interactions. For the induction, we also found no main effect, indicating that automatic retrieval bypasses event construction and accesses pre-stored events. Overall, our evidence suggests that spontaneous retrieval is a promising strategy to support episodic specificity in aging.

Lamb Age has Little Impact on Eating Quality.

There is an industry wide perception that new season lamb has better eating quality than old season lamb. This study aims to identify differences in consumer eating quality scores between two age classes in lamb. Consumer eating quality scores from eight cuts across the carcass were evaluated from new season (NS; n = 120; average age = 240 days) and old season lambs (OS; n = 121; average age = 328 days), sourced from four different flocks. Cuts were grilled (loin, topside, outside, knuckle and rump) or roasted (leg, shoulder, rack) and scored by untrained consumers for tenderness, juiciness, liking of flavour and overall liking. There was no difference in eating quality scores between the two age classes for the loin, leg, shoulder and rack. This was similarly shown in the topside with the exception of juiciness scores where NS lambs were higher than OS lambs. There was also a lack of age difference in the outside with the exception of flock 3 where NS lambs scored higher than OS lambs for all sensory traits. Across all sensory traits, OS lambs received on average 2.8 scores lower for the knuckle and 3.1 scores lower for the rump compared to NS lambs. These results show little difference in eating quality between NS and OS lamb, and highlight the potential to develop high quality OS or “autumn lamb” products, with a similar premium price at retail as NS lambs.

Measures of Implicit Attitudes May Conceal Differences in Implicit Associations

Performance on implicit attitude measures is influenced both by the nature of activated evaluative associations and by people’s ability to regulate those associations as they respond. One consequence is that identical implicit attitude scores may conceal different underlying processes. This study demonstrated this phenomenon and also shed light on the nature of age differences in antiaging bias on implicit attitude measures. Although younger and older participants demonstrated equivalent levels of antiaging bias on an Implicit Association Test (IAT), application of the Quad model showed that antiold associations were less activated among older than younger adults, but that older adults were less able to overcome these associations in performing the task. Thus, the lack of age differences in IAT performance concealed differences in both underlying evaluative associations and the ability to control those associations. These findings have important implications for the measurement and interpretation of implicit attitudes.

Age-dependent responses to thermal hyperalgesia and mechanical allodynia in a rat model of acute postoperative pain.

Developmental differences in short- and long-term responses to pain, especially surgical pain, have received minimal attention. The purpose of the present study was to examine postoperative responses in rats of developmental ages paralleling the infant to young adult human. The withdrawal threshold to von Frey filament testing and withdrawal latency to hind-paw radiant heating were determined before and for various times after hind-paw incision in rats 2, 4, and 16 weeks of age. Control rats of these ages were observed serially without surgery. In control animals, younger rats were more sensitive to mechanical stimulation and less sensitive to thermal stimulation. Paw incision resulted in similar changes to both types of stimulation in all age groups, peaking 4 h after surgery. However, the return to normal sensitivity to mechanical stimulation, as measured by return of threshold to 80% of normal, occurred more quickly in 2-week-old than in 4- and 16-week-old animals. In contrast, there was no age difference for time to return to normal sensitivity to thermal stimulation after surgery. The more rapid recovery of the younger animals from the mechanical allodynia but not thermal hypersensitivity after surgery suggests the presence of developmental differences in modulation of A-fiber sensitization after surgery. However, the lack of age difference in recovery of thermal hypersensitivity after surgery suggests that sensitization of C-fiber input has a similar time course of resolution of pain over the ages studied in this model. The neural bases for these developmental differences are under study and may lead to a better understanding of pain during development and altered approaches to treatment of postoperative pain in neonates and infants.

THIS MONTH IN ANESTHESIOLOGY

THIS MONTH IN ANESTHESIOLOGY

Effects of Domain, Retention Interval, and Information Load on Young and Older Adults’ Visuospatial Working Memory

Age-related differences in visuospatial working memory were examined in 69 young adults and 49 older adults exposed to three pairs of tasks. Each pair consisted of one task involving information about the form or appearance of items and another task involving information about item locations. The first pair of tasks manipulated retention interval and required maintaining information about one item. The second pair also manipulated retention interval and required maintaining information about multiple items presented simultaneously. The third pair manipulated the number of sequentially presented items. Analyses of the first two pairs of tasks revealed significant age deficits in working memory for spatial locations but not in working memory for visual features. Notably, there were no age differences in the effect of retention interval on any of the four tasks, suggesting that visuospatial information is lost at similar rates in older and young adults. Analyses of the third pair of tasks revealed that, regardless of domain, increasing the amount of information impaired older adults’ memory performance to a greater extent than young adults’ performance. Thus, the present results suggest differences in basic working memory capacity in both domains, but a lack of age differences in rates of forgetting from working memory, and greater age-related deficits in the spatial domain than in the object domain.

Lack of age differences in the Beck Depression Inventory-II scores of clinically depressed adolescent outpatients.

To assess whether the mean Beck Depression Inventory-II scores of adolescents who were diagnosed with unipolar depressive disorders differed with respect to age, the inventory was administered to 144 (60%) female and 96 (40%) male outpatients between 13 and 17 yr. who were diagnosed with depressive disorders. The internal consistency of the scores was high (coefficient alpha=.89). A factorial analysis of variance was used to test for the main effects of age, sex, ethnicity, type of depressive disorder, comorbidity, and the two-way interactions of age with the other main effects. The mean scores were not differentiated by age or by the interactions of age with the other effects. The lack of age differences in this 5-year range on the mean scores of clinically depressed adolescents was discussed with respect to previous findings that have reported such differences in adolescents and adults.

LACK OF AGE DIFFERENCES IN THE BECK DEPRESSION INVENTORY-II SCORES OF CLINICALLY DEPRESSED ADOLESCENT OUTPATIENTS

To assess whether the mean Beck Depression Inventory–II scores of adolescents who were diagnosed with unipolar depressive disorders differed with respect to age, the inventory was administered to 144 (60%) female and 96 (40%) male outpatients between 13 and 17 yr. who were diagnosed with depressive disorders. The internal consistency of the scores was high (coefficient α = .89). A factorial analysis of variance was used to test for the main effects of age, sex, ethnicity, type of depressive disorder, comorbidity, and the two-way interactions of age with the other main effects. The mean scores were not differentiated by age or by the interactions of age with the other effects. The lack of age differences in this 5-year range on the mean scores of clinically depressed adolescents was discussed with respect to previous findings that have reported such differences in adolescents and adults.

Denominational and Age Comparisons of God Concepts

This study examines whether denominational and age differences emerge in endorsement of Christian God descriptions developed using the three highest loading adjectives in each of Spilka, Benson, and Nussbaum’s (1964) six God concept factors. Previous research suggests that conceptualizations of God may vary based on religious affiliation, and life‐span development researchers assert that new, adaptive cognitive processes may emerge in later adulthood. Participants were divided into three age categories and asked to rate their agreement to six God descriptions. Significant denominational differences in God factor endorsement were revealed for all factors. No age differences across denomination were determined. Denominational differences appear to corroborate sociological descriptions of denomination‐based variations in religious doctrine and practices. The overall lack of age differences may suggest that God concepts are cognitive organizations that remain stable over time, possibly due to reinforcement from church attendance. All data were collected from church attendees.

Cocaine and morphine-induced place conditioning in adolescent and adult rats

The periadolescent period in the rat is characterized by alterations in novelty seeking and exploratory behavior, as well as changes in the behavioral responsiveness to many drugs of abuse. These alterations may be predictive of alterations in the reward value of drugs of abuse. The present experiments examined whether adolescent rats (34–37 days old) differ from their adult counterparts in the expression of drug-induced place conditioning for morphine (0, 2.5, or 5 mg/kg; Experiment I) and cocaine (0, 5, or 10 mg/kg; Experiments II and III). Animals received multiple conditioning days, followed 24 h later by a drug-free CPP test. All drugs were given intraperitoneally immediately prior to confinement in the CS+ compartment, while vehicle injections were given prior to exposure to the CS− chamber. For both drugs, there were no significant differences between adolescents and adults in amount of place conditioning seen when drug exposure was paired with the nonpreferred chamber. When cocaine was paired with either the preferred or nonpreferred compartment (Experiment III), again, the magnitude of the place conditioning observed did not differ between adolescents and adults. The lack of age differences in expression of drug-induced place conditioning in the present experiments is not likely a result of ceiling effects, because the data suggest that the doses used included near-threshold doses. Although these findings need to be confirmed using other approaches for assessing drug reward before concluding that adolescent and adult rats exhibit similar sensitivity to the rewarding effects of morphine and cocaine, the current data revealed no differences between adolescents and adults in the magnitude of place conditioning expressed for morphine or cocaine.

Age of wife as a major determinant of male-to-female transmission of HIV-2 infection: a community study from rural West Africa.

To examine whether proviral load is important for transmission between spouses, since we have previously found that the proviral load of HIV-2 predicts the severity of infection. Proviral load was examined in 121 HIV-2-infected adults in a rural area of Guinea-Bissau. For the 68 subjects who had a spouse of known HIV status the risk of the spouse being infected was examined. Statistical methods for dependent data were used, because several couples were polygamous. Twenty-seven HIV-2-infected men had 52 current wives of whom 17 (33%) were HIV-2-seropositive. Forty-one HIV-2-infected women had 36 current husbands of known HIV serostatus; nine (25%) were HIV-2-positive. In univariate analyses, concordance of female partners of HIV-2-infected men increased with a previous history of prostitution, age of wife, lack of age difference between the spouses, number of previous husbands, number of wives of the man, and the proviral load. The only significant predictor of concordance in multivariate analyses when wives with a history of prostitution were excluded was an age of 45 years or older [odds ratio (OR), 8.68; 95% confidence interval (CI), 2.34-32.22]. This tendency was not explained by the length of current marriage. Although husbands with a high proviral load were more likely to have concordant spouses than those with a low proviral load (< 20 copies/10(5) CD4 cells), this association was not statistically significant (OR, 2.59; 95% CI, 0.90-7.46). Among spouses of HIV-2-infected women, none of the examined factors, including previous prostitution or proviral load in the woman, predicted whether the husband was HIV-2-infected. Women appear to be more susceptible to HIV-2 infection after 40-45 years of age. The apparent change in susceptibility may be a major reason for the distinctive age pattern of HIV-2 infection observed in West Africa.

Lack of age differences in context-illness associations in the long-delay taste-aversion conditioning of rats.

To evaluate whether previously observed age differences in long-delay taste aversion were due to age-related differences in the shared association of contextual cues and CS with the US, weanling, young-adult, and old-adult rats were given a NaCl or LiCl US immediately after or a LiCl US 3 hr. after a saccharin CS presentation in a black or white context. They were then given a context-preference test in a chamber which was half black and half white. Analysis showed rats, irrespective of age or conditioning context, spent a significantly smaller percentage of time on the white side than on the black side of the test chamber. These results suggest that age differences in long-delay taste-aversion conditioning are not due to age-related differences in the shared association of contextual cues and CS with the US.

Memory for sex-role consistent and inconsistent actions in young and old adults.

Adult age differences in the flexibility of schematic processing were examined by measuring the degree to which a dominant structure (traditional sex-role knowledge) interfered with the operation of a nondominant structure (nontraditional knowledge). In two experiments, young and old adults read statements describing a man performing actions consistent or inconsistent with a prescribed sex role in an impression-formation task. Participants in both age groups altered their processing of the actions, as indicated by reading times and trait ratings, relative to the sex role emphasized, although the effect was stronger for men than women. The expected greater recall for sex role inconsistent than consistent actions was observed only when the traditional sex role was emphasized, and not when the nontraditional role was emphasized, suggesting interference from the dominant schema at recall. However, the lack of age differences in the degree of interference observed during initial processing and recall suggests no aging effects on schematic flexibility.