Showing papers in "Experimental Aging Research in 1975"
TL;DR: The concept of terminal drop was seen to be more useful when partitioned into its component parts: the relationships between the level of cognitive performance with survival and with distance from death, and the relationship between changes in cognitive performance and death.
Abstract: Findings from eight longitudinal investigations were reviewed in order to evaluate the terminal drop hypothesis. The concept of terminal drop was seen to be more useful when partitioned into its component parts: the relationship between the level of cognitive performance with survival and with distance from death, and the relationship between changes in cognitive performance and death. Health status and age at death emerged as important intervening variables in understanding the terminal drop concept.
82 citations
TL;DR: Elderly subjects when compared to young, mature subjects in a memory-scanning task were shown to have longer response times (RT), but a late positive component of the average evoked potential did not reflect this difference between groups.
Abstract: Elderly subjects when compared to young, mature subjects in a memory-scanning task were shown to have longer response times (RT). A late positive component (LPC) of the average evoked potential did not reflect this difference between groups. However, in both groups, the LPC was seen to occur with longer latency at RT increased. LPC amplitudes also declined with increasing RT. There were greater differences between left- and right-hemisphere LPC amplitude and between LPC recorded along the midline scalp in the younger group than in the older subjects.
75 citations
TL;DR: Compared with young mice, aged mice were less active, similar in emotionally, learned the operant discrimination as well, but extinguished more slowly, had poorer discrimination for sweet and bitter taste stimuli, and preferred alcohol to a lesser degree.
Abstract: Young and aged mice of the A/J and C57BL/6J inbred strains were given a series of behavioral tests which measured activity of various kinds, emotionality, operant learning, sensory discrimination, and alcohol preference. In general, compared with young mice, aged mice were less active, similar in emotionality, learned the operant discrimination as well, but extinguished more slowly, had poorer discrimination for sweet and bitter taste stimuli, and preferred alcohol to a lesser degree. Strain differences were obtained for most of these tests, and age-strain interactions occurred frequently indicating that behavioral changes occur at different rates for groups which differ in genetic constitution.
69 citations
TL;DR: In this article, the authors compared reaction time (RT) in 160 hypertensive and 43 normotensive adults after being screened for coronary and cerebrovascular disorders, each subject completed 12 variations of a serial RT task.
Abstract: Reaction time (RT) was compared in 160 hypertensive and 43 normotensive adults After being screened for coronary and cerebrovascular disorders, each subject completed 12 variations of a serial RT task Subjects were blocked into normotensive, nonmedicated hypertensive, and medicated hypertensive groups, and into three age groups: 18–31; 32–45; 46–59 Response slowing was observed with increasing age Significant slowing was also seen in the medicated but not the nonmedicated hypertensive group Plasma renin activity (PRA) interacted with the medication factor; longest RTs were obtained for treated subjects with low and normal PRA and untreated subjects with high PRA These results were interpreted in terms of changes in ability to autoregulate cerebral blood flow as a result of vascular damage
51 citations
TL;DR: An Importance, Locus and Range of Activities Checklist, designed to assess self-perceived latitude of choice, a self concept and a life satisfaction scale were administered to 25 institutionalized and 25 noninstitutionalized elderly females attest to the appropriateness of the technique used to assess perceived latitude ofchoice.
Abstract: An Importance, Locus and Range of Activities Checklist, designed to assess self-perceived latitude of choice, a self concept and a life satisfaction scale were administered to 25 institutionalized and 25 noninstitutionalized elderly females. The checklist contained statements about 37 activities of daily living which subjects rated for personal importance and degree of choice available to them. The derived latitude of choice score was based jointly on importance and choice ratings for each activity. Institutionalized respondents, living in a relatively restrictive environment, earned significantly lower latitude of choice scores than did noninstitutionalized subjects. Latitude of choice, self concept and life satisfaction scores were significantly correlated. These findings attest to the appropriateness of the technique used to assess perceived latitude of choice. Modifications of the Importance, Locus and Range of Activities Checklist designed to provide a more profound measure of latitude of ch...
48 citations
TL;DR: Older subjects were found to be significantly more susceptible to the backward masking effect over longer delays between the target and masking stimuli, indicating a decrease with age in the rate at which stimuli can be cleared through the central mechanisms concerned with perceptual processing.
Abstract: An investigation of age differences in backward dichoptic visual noise masking was carried out with young, middle-aged and old subjects. Older subjects were found to be significantly more susceptible to the backward masking effect over longer delays between the target and masking stimuli. These results indicate a decrease with age in the rate at which stimuli can be cleared through the central mechanisms concerned with perceptual processing. These data appear to support the “stimulus persistence” and “arousal” models of aging.
42 citations
TL;DR: Significantly age and sex differences in scores on the four components (Achievement/Leadership, Congeniality/Sociability, adjustment, and Masculinity-Femininity) emerged and were interpreted.
Abstract: The continuity over the major portion of the life-span (ages 9–89 yrs.) of the connotative structure of the self-concept was examined by factor analysis of a semantic differential instrument and found to be essentially constant. Significant age and sex differences in scores on the four components (Achievement/Leadership, Congeniality/Sociability, Adjustment, and Masculinity-Femininity) emerged and were interpreted.
40 citations
TL;DR: This review examines one such model system, avoidance learning in aging rodents, which has become increasingly popular among behavioral gerontologists, yet it has not provided the unambiguous answers to experimental questions which investigators expected.
Abstract: Animal models of human aging problems are potentially of enormous value to gerontological research. Models of behavioral problems have not often lived up to their promise. This review examines one such model system, avoidance learning in aging rodents. This model system has become increasingly popular among behavioral gerontologists, yet it has not provided the unambiguous answers to experimental questions which investigators expected. Our effort has been to determine why the system has failed, and to provide useful suggestions for future research. At the same time we have tried to provide a comprehensive review of the relevant literature and to assess the strengths and weaknesses of studies which have been conducted in the last two decades.
32 citations
TL;DR: The behavioral characteristics of C57BL/6J, DBA/2J, and B6D2F1, hybrid mice which are most likely to be of interest to gerontological scientists are summarized to acquaint gerontologists with the availability of genetically defined animal models for aging research.
Abstract: This review summarizes the behavioral characteristics of C57BL/6J, DBA/2J, and B6D2F1, hybrid mice which are most likely to be of interest to gerontological scientists. Where possible, the characteristics of young and old mice are included. Where no information exists about the behavior of older mice of these genotypes, but there is reason to believe that information about mice might be useful for aging research, this information is included. The purpose of the review is to acquaint gerontologists with the availability of genetically defined animal models for aging research, to present what is known about these models, and to suggest areas of research which could profit from more attention.
30 citations
TL;DR: Trends in the data suggested that the younger subjects had lower real and ideal self ratings and were less satisfied with their lives than the elderly subjects (60-75 years).
Abstract: Six age groups were compared with respect to discrepancy between real and ideal self concepts and the relationship between life satisfaction and discrepancy in self concepts. The subjects, ranging in age from 20 to 75 years, completed two self descriptive adjective rating scales which assessed real and ideal self concept and a life satisfaction index. Significant differences were found among age groups for real and ideal self concepts, life satisfaction, and discrepancy between real and ideal self concept scores. Age was significantly correlated with real and ideal self concept, discrepancy between real and ideal self concepts and life satisfaction. Life satisfaction was significantly correlated with real self concept and discrepancy between real and ideal self concepts. Trends in the data suggested that the younger subjects (20-25 years) had lower real and ideal self ratings and were less satisfied with their lives than the elderly subjects (60-75 years).
26 citations
TL;DR: Two partial solutions are suggested that deal with the confounding of age effects with such uncontrolled variables as, for example, initial ability level or level of education.
Abstract: Geron-tological researchers are reminded of the inappropriateness of analysis of covariance wherein the covariate is correlated with the independent variable, typically age. Two partial solutions are suggested that deal with the confounding of age effects with such uncontrolled variables as, for example, initial ability level or level of education.
TL;DR: Four age groups of C57BL/6J mice were subjected to either immobilization or handling procedures, although both locomotor activity and exploratory behavior declined with advancing age, and Exploratory behavior was observed to be a more complex function of both age and experience.
Abstract: Four age groups of C57BL/6J mice (2.2, 6.2, 12.0, and 23.3 months) were subjected to either immobilization or handling (control) procedures. Open field behavior was observed before and after experimental treatments and plasma corticosterone levels were assessed 11 days following the immobilization or handling procedures. Eleven days following immobilization elevated corticosterone levels were observed for all but the 12.0 month group of mice. No behavioral effects were observed for the experimental groups, although both locomotor activity and exploratory behavior declined with advancing age. The age-related decrease in activity was entirely accounted for by scores on the initial open field test. Exploratory behavior was observed to be a more complex function of both age and experience.
TL;DR: There is evidence that mothers play an important role in mediating many early experience effects in rat of maturity and that differential maternal responsiveness in different stocks of laboratory animals may correlate with differences in neonatal ultrasonic calling.
Abstract: The developmental course of ultrasonic signaling by neonatal rat pups (Rattus norvegicus) was monitored under varying degrees of hypothermic stress Signal rate, peak frequency, duration, and complexity of signals were analyzed separately for two different laboratory stocks Sprague-Dawley and Wistar/Furth Additionally, preliminary data were obtained on maternal retrieval latencies during the 1st 4 days post-partum and compared with the emission rate of neonatal ultrasounds On the basis of these and other data, there is evidence that mothers play an important role in mediating many early experience effects The data suggests that rate of neonatal ultrasounds may provide an index of some aspects of rat of maturity; that there may be different periods of maximum sensitivity to external stimulation in various stocks of laboratory animals; and that differential maternal responsiveness in different stocks of laboratory animals may correlate with differences in neonatal ultrasonic calling Implications for comparative, genetic, and developmental studies are discussed
TL;DR: The results indicate that early malnutrition delayed the development of the reflex and ECoG activities and permanently altered brain growth and avoidance learning and strains characterized by a slower development of brain function do not show early signs of brain malfunction following undernutrition.
Abstract: The development of a number of reflex activities, of the electrocorticogram (ECoG), and measures of brain and body weight were assessed at different ages from birth to maturity in mice belonging to Swiss-Webster stock and two inbred strains (C57BL/6J and SEC/1Re). The animals also were tested at 60 days of age for exploratory activity and avoidance behavior. These effects of postnatal undernutrition on the measures of reflex and ECoG activity, brain and body weight and avoidance learning were determined at different ages after birth and in adult animals following dietary rehabilitation. Undernutrition during suckling period was introduced by increasing the litter size from 4 pups to 8 or 16 pups per litter. The results indicate that early malnutrition delayed the development of the reflex and ECoG activities and permanently altered brain growth and avoidance learning. The effects were different, depending on the genotype considered. The data indicate that strains characterized by a slower development of brain function do not show early signs of brain malfunction following undernutrition.
TL;DR: It was raised that compensatory mechanisms for high blood pressure, e.g., cardiac hypertrophy, may operate very early in development for animals who are hypertensive by virtue of selective breeding for blood pressure extremes.
Abstract: Mice selected genetically for high and low blood pressure (BP) were compared with regard to heart weight and heart/body ratios. Two experiments were performed with mice ranging in age from 1.3 to 9 months and 11 to 23 months respectively. In a third experiment C57BL/6J mice were compared to the high and low BP mice. Heart/body ratios and heart weights, adjusted for body weight via covariance analysis, were significantly greater for the high BP mice, but no Age x BP Genotype interaction was observed. Results were discussed in terms of a possible relationship between heart weight and BP via genetic linkage or pleiotropy. The possibility was also raised that compensatory mechanisms for high blood pressure, e.g., cardiac hypertrophy, may operate very early in development for animals who are hypertensive by virtue of selective breeding for blood pressure extremes.
TL;DR: It is concluded that differences in enzyme levels to not provide a simple characterization of aging processes.
Abstract: Recent literature age differences in enzyme levels of mice is reviewed and related to reported differences in physiological processes. It is concluded that differences in enzyme levels to not provide a simple characterization of aging processes.
TL;DR: The presence study contrasted young and middle-aged subjects on two components of a recognition memory task (a modified verbal discrimination task) that differed in level of difficulty, finding no age decrement for the easier component requiring discriminability between the oldness and newness of items.
Abstract: The present study contrasted young and middle-aged subjects on two components of a recognition memory task (a modified verbal discrimination task) that differed in level of difficulty. No age decrement was found for the easier component requiring discriminability between the oldness and newness of items. In addition, age was not a factor in determining the effects of prior relevance or irrelevance of item information on old-new discriminability. An age decrement was found for the more difficult component requiring discriminability in terms of an old item's prior function in the study list. The decrement occurred for the identification of prior function of both right and wrong items.
TL;DR: It was concluded that the sorting technique and measures related to it failed to detect the elderly adults' apparent difficulty in acquiring the sentences.
Abstract: Differences between elderly and young adults in storage organization of sentence material were investigated using a modification of Mandler's (1967) sorting technique. The elderly were expected to be relatively poorer at sorting organization, and would then recall less sentence material. The age groups were also compared on time taken to organize the sentences, recall organization, and performance on a short sentence comprehension test. There were no age differences in conceptual type of organization or clustering of sentences in sorting groups and recall storage organization was not related to the amount of recall. The elderly adults did require more time to acquire the sentences, and had lower recognition test scores. It was concluded that the sorting technique and measures related to it failed to detect the elderly adults' apparent difficulty in acquiring the sentences.
TL;DR: Information provided by Monge and Hultsch in support of the pacing variable was reinterpreted i terms of the total time principle and the re-analysis of the transformed data suggests that thetotal time principle provides a more parsimonious explanation of the data.
Abstract: Winn, F.J., Jr. and J.W. Elias. The total time principle as a substitute for the pacing variable in paired-associate tasks with the aged. Experimental Aging Research, 1975, 1 (2), 307–312. Information provided by Monge and Hultsch in support of the pacing variable was reinterpreted in terms of the total time principle. The re-analysis of the transformed data suggests that the total time principle provides a more parsimonious explanation of the data.
TL;DR: The hippocampal theta rhythm in rats exhibited an age-dependent slowing in modal frequency, however, the theta Rhythm of young rats with chronic respiratory infections showed a similar slowing, and Respiratory disease-free hamsters also exhibited anAge- dependent slowing of modal frequencies.
Abstract: The hippocampal theta rhythm in rats exhibited an age-dependent slowing in modal frequency. However, the theta rhythm of young rats with chronic respiratory infections showed a similar slowing. Respiratory disease-free hamsters also exhibited an age-dependent slowing of modal frequencies. These findings emphasize that the health status of the animal must be examined carefully in order to establish an age-dependent slowing in hippocampal rhythm.
TL;DR: Interpretation is offered that C57BL/6J mice possess a more labile norepinephrine system, in spite of aging, than DBA/2J mice.
Abstract: Activity levels of COMT were measured in the frontal cortex, hippocampus, hypothalamus and amygdala of two strains of male mice, C57BL/6J and DBA/2J, at various ages between 2 and 30 months. Determinations were made in mice housed under normal conditions and in mice exposed to a form of mild stress, an open-field apparatus, for 5 minutes. There were no major significant differences between the two strains as a function of age. However, after the open-field experience, C57BL/6J mice appeared significantly more responsive to the environment, as interpreted by increases in COMT, than DBA/2J mice. Interpretation is offered that C57BL/6J mice possess a more labile norepinephrine system, in spite of aging, than DBA/2J mice.
TL;DR: How close individuals seat themselves to an interviewer was studied as a function of subjects' age and expectations regarding the interviewer to reflect a greater susceptibility among older individuals to feeling threatened and ill-at-ease in an interpersonal situation.
Abstract: How close individuals seat themselves to an interviewer was studied as a function of subjects' age and expectations regarding the interviewer. An experimental approach situation was used and the subjects were 10 college students and 10 residents of a county home. Those subjects who had been told to expect an unpleasant interaction seated themselves significantly farther from the interviewer than did those who expected a pleasant interaction. Also, the older subjects seated themselves significantly farther from the interviewer than the younger subjects did. The difference between the age groups was minimal when the subjects' expectations were positive, but was pronounced when the subjects' expectations were negative. The results appear to reflect a greater susceptibility among older individuals to feeling threatened and ill-at-ease in an interpersonal situation.
TL;DR: The data indicate that sharing of information between hemispheres under certain circumstances increases the efficiency of information processing relative to that observed with unilateral visual half-field (hemisphere) presentations and that hand or finger response relative to visual field of presentation is an important factor which must be controlled and examined relative toVisual field of present.
Abstract: Young, middle aged, and older subjects were given a Posner-type physical-name matching task, in which stimuli were presented to one or both hemispheres, and a simple discrimination reaction time (DRT) task. Reaction time differed between young and middle aged groups for both tasks with shorter RT for the DRT task. Reaction time for the older group did not differ significantly from that of the middle aged group for either task, although the reaction time for the older group was longer. Reaction time was faster for all age groups when Stimulus 1 and Stimulus 2 were presented to different hemispheres for the matching task than when both stimuli were presented to the same hemisphere. Ipsilateral finger responses (hand relative to hemisphere) were slower than contralateral responses but this was true only with regard to the visual field of presentation for stimulus 2. These data indicate that sharing of information between hemispheres under certain circumstances increases the efficiency of information processing relative to that observed with unilateral visual half-field (hemisphere) presentations and that hand or finger response relative to visual field of presentation is an important factor which must be controlled and examined relative to visual field of presentation.
TL;DR: The possibility was raised that procedures designed to allow recovery from post surgical shock and adaptation to electrode connections may result in disproportionate differences across age groups.
Abstract: Some methodological problems encountered in age comparisons of EEG patterns are discussed in the context of an analysis of open field activity scores before and after preparation for, and recording of EEG sleep patterns. Plasma corticosterone levels 11 days after surgery for EEG electrode implantation were also measured. Activity levels were modified more for three older than for a younger group of animals following surgery/recording sessions. Corticosterone levels were appreciably elevated for the oldest group of animals. The possibility was raised that procedures designed to allow recovery from post surgical shock and adaptation to electrode connections may result in disproportionate differences across age groups.
TL;DR: Findings from socioeconomic status, age, social participation, health, community, housing, family, work, morale, and longevity variables indicate pre-retirement planning approaches should be developed for those having different work-ret retirement attitudes.
Abstract: After a typology is developed based on work satsifaction and attitude toward retirement, profiles are examined of respondents appearing in four typological categories. Data at three points in time (1964, 1966, 1974) from 1,922 older (50 +) employed males suggest that members of some types wilt be more susceptible to negative consequences of life-cycle change (work to retirement) than others. Findings from socioeconomic status, age, social participation, health, community, housing, family, work, morale, and longevity variables indicate preretirement planning approaches should be developed for those having different work-retirement attitudes.
TL;DR: The results suggest that naive mothers can be "primed" to exhibit greater maternal responsiveness than is characteristic of primiparous mothers.
Abstract: Prior to mating, virgin female Long-Evans Rutins norvegicus received 30 classical CER trials with shock as the UCS and either taped neonatal ultrasounds or a belltone as the CS. Additional animals were placed in groups controlling for exposure to shock, the ultrasounds, the belltone, and placement in the conditioning apparatus. Following mating and parturition mother-infant observations revealed that those mothers previously conditioned to neonatal ultrasounds spent more time in the lactation posture than did mothers from the other groups. The results suggest that naive mothers can be “primed” to exhibit greater maternal responsiveness than is characteristic of primiparous mothers.
TL;DR: The data on the effect of age on the enzymatic digestive process are not totally clear, but it seems unlikely that if such changes do occur that they are of a magnitude to seriously hamper the digestive function of the senescent rat.
Abstract: There is little published information on the pulmonary function of aged rats. The data available indicate that the elastic properties of the lung-thorax system of the rat changes with age in a fashion similar to that seen in the case of man and other mammals. However, unlike the situation observed with man, neither the internal surface area of the lungs nor the diffusing capacity of the lungs declines as the rat ages. The diffusion O2 from blood to tissues does not seem to decline with age in the rat and the utilization of O2 by the tissues is either not affected by old age or affected in a subtle fashion. There is no information on how old age influences either the motility or the secretory activity of the exocrine glands of the alimentary tract of rats. There is abundant evidence to indicate that the processes involved in the absorption of dietary carbohydrate and protein are not adversely affected by old age in rats. The data on the effect of age on the enzymatic digestive process are not totally clear, but it seems unlikely that if such changes do occur that they are of a magnitude to seriously hamper the digestive function of the senescent rat.