Twenty-four-hour sleep-wake patterns in a nursing home population

Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.     

Relationship of severity of dementia to caregiving stressors

In studies of individual differences and longitudinal changes in stress and coping among dementia caregivers, assessing severity of patient impairment is critically important. It is proposed that with the progression of dementia, cognitive impairment may steadily increase, but other stressful behavioral symptoms peak at various stages of dementia. Cross-sectional data from 49 caregiving families and longitudinal follow-up data from 48 families suggest that instrumental self-care deficits begin early in dementia, and basic self-care deficits increase with dementia severity, but that many distressing behavioral symptoms decrease in late dementia. Assessments of dementia patient severity should be multidimensional, and increases and decreases in various dementia patient stressors over time should be considered as factors influencing caregiver coping.     

Assessing White Racial Consciousness and Perceived Comfort with Black Individuals: A Preliminary Study

This research examined the relationship between White racial consciousness development and perceived comfort with Black individuals. Participants were 339 White undergraduate students from a large southeastern state university who were asked to complete a two-part inventory: part one measuring White racial consciousness development (a five-stage scale) and part two measuring perceived comfort in situations involving Black individuals. An eta coefficient was calculated, providing evidence for the existence of a strong curvilinear relationship between White racial consciousness and perceived comfort with Black individuals η =.23 at p<.0001. These findings suggest that Whites who are completely foreclosed (stage one) or who are well acquainted with Blacks (stage five) are more comfortable in situations with Blacks than Whites who had a moderate amount of contact with them (stages two, three, and four).     

Task-unrelated-thought frequency as a function of age: a laboratory study

Using retrospective reports, Giambra (1977-1978, 1979-1980) found an inverse relation between age and daydreaming/mind wandering. To deal with an alternate explanation of these results based on age-dependent memorial deficiencies and attitudes toward daydreaming/mind wandering and to provide independent convergent validity, five experiments were carried out. Task-unrelated thoughts (TUTs) were taken as the operational definition of daydreams/mind wanderings and their frequency recorded in vigilance tasks. All five experiments found an inverse relation between age (17-92 years, N = 471) and TUTs, confirming the reliability and validity of the earlier studies. The age-dependent reduction in TUTs was considered as evidence of reduced nonconscious information processing with increased age. The results of this study were incompatible with a recent theory that predicts for older individuals an increased input of irrelevant thoughts into working memory due to the older individual's reduced inhibitory control.     

Age, exercise, and coding performance

We investigated the effects of exercise on the coding performance of young and older subjects. Hypotheses were tested that exercise either facilitates spatial localization or reduces susceptibility to distraction in older subjects. In a balanced design, we administered Digit Symbol and Symbol Digit coding tasks to exercisers and nonexercisers at two age levels under conditions of low or high within-task interference. The findings showed higher performance by the exercisers than by the nonexercisers only at the older age level and only with the Symbol Digit task. These findings support the hypothesis that exercise compensates for a loss of spatial localization skills with age. We found no evidence that susceptibility to distraction either increased with age or was affected by chronic exercise.     

Age differences in source forgetting: effects on reality monitoring and on eyewitness testimony

Age differences in memory for the source of memories were investigated using two different experimental paradigms. Experiment 1 used a reality monitoring paradigm. A series of actions were either performed, imagined, or watched, and subjects were later tested for their ability to recognize the actions and identify their origins. Elderly subjects made more false positive responses than did young subjects, and they made more source confusion errors, attributing actions to the wrong sources. Both new and imagined actions were most often misclassified as watched. Experiment 2 used an eyewitness testimony paradigm. After watching a film, subjects read a written version of the story. A recognition test showed that elderly subjects were more often misled by false information in the story than were the younger subjects, and were more confident that their erroneous responses were correct. The findings suggest that a decline in memory for sources may diminish the accuracy of elderly witnesses.     

Frontal lobe dysfunction and memory impairment in patients with chronic progressive multiple sclerosis

Deficits in semantic encoding have been described in patients with frontal lobe disease who also show memory impairments. As a group, patients with multiple sclerosis (MS) exhibit memory impairment, fail to make effective use of semantic encoding to aid memory, and perform poorly on verbal fluency and concept formation tests which are sensitive to frontal lobe damage. In the present study the semantic encoding capacity of MS patients was measured using a modification of Wicken's release from proactive interference (PI) paradigm. Individual patients varied considerably in the severity of their impairments on verbal fluency, verbal recognition memory and on Wisconsin Card Sorting Task, but even patients who evidenced both memory impairment and signs of frontal lobe dysfunction showed normal release from PI after a categorical shift. Memory disturbances in MS are unlikely to result from an incapacity for semantic encoding, which seems preserved in MS, but may arise instead from deficits in processing information rapidly.     

Forecasting the impact of the federal sentencing guidelines

The Sentencing Reform Act of 1984, which created the U.S. Sentencing Commission, required that the commisson consider prison capacity in drafting sentencing guidelines. As part of the commission's efforts to meet this requirement, we developed a computer simulation capable of projecting the impact of the commission's guidelines on future sentences and prison populations. According to our projections, “straight” probation sentences will be reduced significantly under the guidelines. However, reducing the use of probation will generate only modest demands on the prisons, and then mostly for community corrections phased in over the course of 5 years. We also project that, while average time served for violent offenses will increase substantially, average time served for most property crimes will remain largely the same. Finally, while we forecast that federal prison populations will grow markedly by the end of this century, this is more a result of the Anti-Drug Abuse Act of 1986 and the career offender provision of the Comprehensive Crime Control Act of 1984 than a result of the guidelines.     

Central-place foraging by Rattus norvegicus on a radial maze

We studied central-place foraging in rats (Rattus norvegicus) by placing food items that varied in size and weight at the ends of a 4-arm radial maze. In Experiments 1-3, rats increasingly tended to carry food to the center of the maze as the size of those items increased. Very large food items often were hoarded in the center. Rats consumed food faster on the arms than in the center, and rats traveled faster when carrying food than when not. Blocking arm entrances increased travel time between the center and the arms and decreased food carrying at every item weight except the largest. In Experiments 4-6, important conditions that influence the degree of food-carrying behavior were discovered; these were the intersection of maze arms, the presence of a conspecific, and the use of open vs. closed maze arms.     

Song frequency as a cue for recognition of species and individuals in the field sparrow (Spizella pusilla)

Estimate the amount of frequency variation that affected individual and species recognition by song in territorial male field sparrows with field playbacks of neighbors' songs lowered in frequency in 6 increments between 324 and 1296 Hz. Males gave strong responses to neighbors' songs that had been lowered by about 400 Hz, which is about 11% of the mean midfrequency in field sparrow song. Territorial responses were eliminated when neighbors' songs were lowered by more than about 900 Hz. Thus, there is a fairly narrow range of frequencies within which field sparrow songs can vary while functioning in communication. Ss' responses appear to be constrained by the normal range of song frequency variation within the species, but the range of variability within songs of individuals did not influence the degree of frequency shift required to render neighbors' songs unfamiliar.