Performance enhancement in a semi-autonomous confined microsociety

Research in a continuously programmed human experimental laboratory has been directed toward identifying, defining, and expanding generalized knowledge concerning motivational factorswithin the structure of human behavioral repertoires that maintain and enhance performance. Participants (in groups of three) engaged in a series of repetitive work activities (e.g., word sorting and rug-hooking) for extended periods each day, while living continuously in a residential laboratory. Other parts of the day were spent either interacting socially with other participants or engaging in individual recreational activities. The percentage of time devoted to the various work tasks provided the basis for selecting one activity that occurred with high frequency and one with low frequency. Performance of the low-frequency activity was then required in order to gain access to the high-frequency activity. Under such contingencies, time devoted to the original low-frequency activity increased greatly, and the participants consistently did more than the required amount of the low-frequency work than was necessary to restore access to the restricted work activity. The theoretical significance of these findings resides in the clear demonstration that a time-based model of value applies as well to the enhancement of work-like performance as it does to voluntarily selected or preferred recreational activities. Supported by Grant NASA (NAG 2-139) from the National Aeronautics and Space Administration.     

Comparison of the RT3 Research Tracker and Tritrac R3D accelerometers during a backpacking expedition by a single subject

This study compared the RT3 Research Tracker accelerometer and the Tritrac R3D accelerometer in a field setting. A six-day backpacking expedition (122.4 km in length) was completed by a single subject in the Grand Canyon National Park, Arizona. The overall correlation between the counts of vector magnitude activity for the RT3 and R3D was moderate (r =.75, p<.001), with the overall calculated bias [mean difference (RT3 minus R3D) and standard deviation of the differences] across all six days estimated at 235+/-436 vector magnitude activity counts. However, agreement between the instruments is problematic; the RT3 might be 201 activity counts below or 671 activity counts above the R3D in assessing physical activity during backpacking.     

No pain, no gain: Perceptions of calorie expenditures of exercise and daily activities

Reduction in physical activity is considered a major contributor to weight problems. Increasingly, people are expending less energy in household chores but joining fitness clubs. Do people perceive ordinary daily activities to expend less energy than exercise activities using similar amounts of calories? In the present study college students were asked to evaluate the calorie expenditure of 30 physical activities (i.e., exercises and household tasks). The household tasks were matched (in terms of caloric expenditure) to at least one exercise activity. When participants rated both exercise and daily activities, it appears that they focused on rate of caloric expenditure rather than type of activity (i.e., household task or exercise). In Study 2, college students evaluated the energy expenditure of light/leisure, moderate, and intense exercise. This emphasis concerning the benefit of intense physical activity was observed once again. College students appear to have assimilated the belief that intense physical activity expends more energy than longer sessions of lower intensity physical activity using similar amounts of calories. Perhaps one reason why people are not physically active is that they believe physical activities must be intense to be of benefit. At the same time they are automatizing household chores and, thus, become less active overall.     

Specific fears as predictors of generalized anxiety in children

The study investigated the relationship between fear and anxiety in childhood. One hundred fifty-one children aged 6 to 11 years (mean=8.7 years) completed the Fear Survey Schedule for Children-Revised (FSSC-R) and the Revised Children's Manifest Anxiety Scale (RCMAS). Correlational analyses demonstrated that the FSSC-R and each of the fear factors were significantly correlated with each other and with the RCMAS score. A stepwise regression procedure was used to determine if the FSSC-R or any of its five factors was significantly related to scores on the RCMAS. Results indicated that Factor 1 (Failure and Criticism) accounted for 31% of the variance (p < .0001)and Factor 2 (Fear of the Unknown) accounted for an additional 1% of the variance (p < .03)in the RCMAS scores. The relationship between these results and those from a similar study with adults (Goetsch, Tishelman, & Adams, 1987), as well as how the results add to an understanding of childhood anxiety, is discussed.This study was supported by BRSG Grant S07RR0714917 from the Biomedical Research Support Grant Program, Division of Research Resources, National Institute of Health, to the Research Foundation of the State University of New York at Binghamton.     

Male and female teachers: Do they treat boys and girls differently?

Forty experienced and inexperienced teachers, 20 male and 20 female, were observed during free play periods in preschool classes. Male teachers gave more favorable comment than female teachers, and also more physical affection. Male teachers also joined the play of the children more than female teachers. Female teachers interacted less than male teachers. Experienced teachers initiated behaviors, directed, gave information, asked and answered questions, and helped the child more than inexperienced teachers. Experienced teachers interacted more with boys and girls when they engaged in feminine-preferred activities, with no difference between male and female teachers in this regard. Inexperienced teachers of both sexes interacted more with boys engaging in masculine-preferred activities and girls engaging in feminine-preferred activities. It was suggested that the male stereotype and the school environment are less congruent than the female stereotype and school, and that experienced teachers encourage children to engage in school-type activities.This research was supported by a grant from the Office of Scientific and Scholarly Research, Graduate School, University of Oregon. Data analyses were supported by BRSG Grant RR 07080 awarded by the Biomedical Research Support Grant Program, Division of Research Resources, National Institutes of Health.     

No pain, no gain: Perceptions of calorie expenditures of exercise and daily activities

Reduction in physical activity is considered a major contributor to weight problems. Increasingly, people are expending less energy in household chores but joining fitness clubs. Do people perceive ordinary daily activities to expend less energy than exercise activities using similar amounts of calories? In the present study college students were asked to evaluate the calorie expenditure of 30 physical activities (i.e., exercises and household tasks). The household tasks were matched (in terms of caloric expenditure) to at least one exercise activity. When participants rated both exercise and daily activities, it appears that they focused on rate of caloric expenditure rather than type of activity (i.e., household task or exercise). In Study 2, college students evaluated the energy expenditure of light/leisure, moderate, and intense exercise. This emphasis concerning the benefit of intense physical activity was observed once again. College students appear to have assimilated the belief that intense physical activity expends more energy than longer sessions of lower intensity physical activity using similar amounts of calories. Perhaps one reason why people are not physically active is that they believe physical activities must be intense to be of benefit. At the same time they are automatizing household chores and, thus, become less active overall.     

Sensorimotor skills and language comprehension in autistic children

The objectives of this study were to examine the level of sensorimotor concepts of young autistic children and to relate these concepts to language comprehension. A sample of 16 autistic children with a mean mental age of 24.8 months was administered a standardized scale of sensorimotor intelligence and of receptive language. The autistic children demonstrated surprisingly sophisticated sensorimotor skills, particularly object permanence. While their initial performance was inferior to that of normal controls matched on mental age, particularly in their use of objects in combination, the difference between groups diminished on the second test administration. On the receptive language measure, the autistic children were less able to identify words correctly. The sensorimotor behavior of autistic children who demonstrated language comprehension did not differ from those who showed no language comprehension, except that the former group tended to use an object as an instrument somewhat more frequently. The fact that the autistic children were so impaired in language even with fairly good sensorimotor skills suggests that these skills, particularly object permanence, play a minor role in their language acquisition.Support for this research was provided by Biobehavioral Research Support Grant 516, Grant 12–41 from the March of Dimes, NIMH Postdoctoral Fellowship No. 1 F32 MH07550-01 (Ungerer), and NIMH Grant MH 33815-01. Subjects were recruited from the UCLA Research Center for the Study of Childhood Psychosis, funded by NIMH Grant MH 30897. We would like to thank members of the CRC, particularly Dr. Peter Tanguay, Dr. Barbara Fish, and Dr. B. J. Freeman, for their support of our research efforts.     

Reliability and validity of the tritrac-R3D accelerometer during backpacking: a case study.

This study investigated the utility of the Tritrac-R3D accelerometer as a reliable and valid instrument in the quantification of physical activity while backpacking in the field and to evaluate heart-rate responses and oxygen consumption to assess the feasibility of using the Tritrac-R3D to estimate caloric expenditure. Two 7-day backpacking expeditions were conducted in two consecutive years by a single subject at Grand Canyon National Park, Arizona. The average hiking heart rate ranged front 60% to 77% HRmax during the expeditions. The average rate of estimated caloric cost ranged from 6.8 to 11.7 kcals x min.(-1) (equivalent to 408 to 702 kcals x hr.(-1)), indicating a relatively moderate to high level of exertion. The Tritrac had adequate consistency and reliability in the field between the two expeditions in recorded activity counts. The Tritrac underestimated caloric expenditure during backpacking with changes in terrain, and hiking speed contributed to even greater disparity in accuracy.     

Continuous self-monitoring of discomfort in the dental chair and feedback to the dentist

The purpose of this study was to examine a continuous measurement of discomfort given by patients during aversive and nonaversive dental activities. To demonstrate the sensitivity of the measurement, the degree of feedback to the dentist about discomfort and the belief in that feedback were varied during oral examination, topical application, and injection of anesthesia. Patients operated buttons which were connected to a recorder and to light which signaled levels of discomfort to the dentist. The lights were operating during the dental activities for the Actual Feedback Group but not for the Belief in Feedback or the No Feedback Group. Subjective ratings of discomfort were also taken after each dental activity. The behaviorally based self-monitoring measure was more sensitive to variations in dental activities than were self-ratings. It showed differences across groups during the aversive, but not the nonaversive, events; showed differences in the delay of discomfort across groups; and suggested a decay in the belief in feedback effect with noncontingent dental response to discomfort responses.This study was supported in part by Research and Training Center Grant 16-P-56812, RT-13 from the National Institute of Handicapped Research, Office of Special Education, Department of Education.     

“Sherry’s Secret”

The case and commentaries below were developed as part of a project, Graduate Research Ethics Education, undertaken by the Association for Practical and Professional Ethics with funding from the National Science Foundation (NSF Grant No. SBR 9421897 and NSF Grant No. 9817880). The project aims at training graduate students in research ethics and building a community of scientists and engineers who are interested in and capable of teaching research ethics. As part of the project, each graduate student participant develops a case for use in teaching and writes a commentary to go with the case, and then a staff member is asked to write additional commentary on the case. The case below was written in the second year of the project and was published in Research Ethics: Cases and Commentaries edited by B. Schrag, Association for Practical and Professional Ethics, Bloomington, Indiana, Vol. II (1998). Publication of these cases and commentaries will be a recurring feature of Science and Engineering Ethics.     

Memory for metaphors

Three experiments examined memory for metaphorical sentences. No differences between metaphors and nonmetaphorical equivalents (e.g.,The ivy cuddled up to the window vs.The ivy grew up to the window) in the number of correct recalls or recognitions were found. There was, however, a significant trend for recall errors that were meaning-preseving to be less metaphorical than the input sentence. The results supported hypotheses that metaphors and nonmetaphors are equally easy to remember and that the stored memory representation does not distinguish whether its antecedent linguistic input was metaphorical or not.This research was supported by Grant MH 28493-01 from NIMH and by a grant from the Kansas State University Bureau of General Research.Some of the data were reported at the Meeting of the Psychonomic Society, Denver, November 1975.     

On equivariance and invariance of standard errors in three exploratory factor models

Current practice in factor analysis typically involves analysis of correlation rather than covariance matrices. We study whether the standardz-statistic that evaluates whether a factor loading is statistically necessary is correctly applied in such situations and more generally when the variables being analyzed are arbitrarily rescaled. Effects of rescaling on estimated standard errors of factor loading estimates, and the consequent effect onz-statistics, are studied in three variants of the classical exploratory factor model under canonical, raw varimax, and normal varimax solutions. For models with analytical solutions we find that some of the standard errors as well as their estimates are scale equivariant, while others are invariant. For a model in which an analytical solution does not exist, we use an example to illustrate that neither the factor loading estimates nor the standard error estimates possess scale equivariance or invariance, implying that different conclusions could be obtained with different scalings. Together with the prior findings on parameter estimates, these results provide new guidance for a key statistical aspect of factor analysis.We gratefully acknowledge the help of the Associate Editor and three referees whose constructive comments lead to an improved version of the paper. This work was supported by National Institute on Drug Abuse Grants DA01070 and DA00017 and by the University of North Texas Faculty Research Grant Program.     

Essential independence and likelihood-based ability estimation for polytomous items

A definition ofessential independence is proposed for sequences of polytomous items. For items satisfying the reasonable assumption that the expected amount of credit awarded increases with examinee ability, we develop a theory ofessential unidimensionality which closely parallels that of Stout. Essentially unidimensional item sequences can be shown to have a unique (up to change-of-scale) dominant underlying trait, which can be consistently estimated by a monotone transformation of the sum of the item scores. In more general polytomous-response latent trait models (with or without ordered responses), anM-estimator based upon maximum likelihood may be shown to be consistent for under essentially unidimensional violations of local independence and a variety of monotonicity/identifiability conditions. A rigorous proof of this fact is given, and the standard error of the estimator is explored. These results suggest that ability estimation methods that rely on the summation form of the log likelihood under local independence should generally be robust under essential independence, but standard errors may vary greatly from what is usually expected, depending on the degree of departure from local independence. An index of departure from local independence is also proposed.This work was supported in part by Office of Naval Research Grant N00014-87-K-0277 and National Science Foundation Grant NSF-DMS-88-02556. The author is grateful to William F. Stout for many helpful comments, and to an anonymous reviewer for raising the questions addressed in section 2. A preliminary version of section 6 appeared in the author's Ph.D. thesis.     

Polytomous IRT models and monotone likelihood ratio of the total score

In a broad class of item response theory (IRT) models for dichotomous items the unweighted total score has monotone likelihood ratio (MLR) in the latent trait. In this study, it is shown that for polytomous items MLR holds for the partial credit model and a trivial generalization of this model. MLR does not necessarily hold if the slopes of the item step response functions vary over items, item steps, or both. MLR holds neither for Samejima's graded response model, nor for nonparametric versions of these three polytomous models. These results are surprising in the context of Grayson's and Huynh's results on MLR for nonparametric dichotomous IRT models, and suggest that establishing stochastic ordering properties for nonparametric polytomous IRT models will be much harder.Hemker's research was supported by the Netherlands Research Council, Grant 575-67-034. Junker's research was supported in part by the National Institutes of Health, Grant CA54852, and by the National Science Foundation, Grant DMS-94.04438.     

Differences between right versus left lateral body tilt in its effect on the visual and tactual perception of verticality

Summary Ninety six Ss were subjected to lateral body tilt, ranging from 10° to 90° to the right and to the left, and indicated the visual vertical (by means of a luminescent rod) and the tactual vertical (by means of a metal bar) in a darkroom. There were significant differences for deviations of apparent from true vertical in both series between body tilt to the right versus to the left. With tilts to the right, apparent vertical deviated more opposite the direction of tilt, the E-phenomenon, or less in the direction of tilt, the A-phenomenon, as compared with tilts to the left.This study was supported, in part, by a Public Health Service Research Grant, MH 00348, from the National Institute of Mental Health, while the author was a NATO research fellow at Clark University, Worcester, MA; and in part by a Federal Grant, MR HD 06276, to the Children's Hospital Medical Center, while the author was a research fellow in child psychiatry at Harvard University, School of Medicine, Boston, MA.     

Millon Clinical Multiaxial Inventory (MCMI) scores with a collegiate sample: Long-term stability and self-other agreement

This study examined (a) the stability of the personality and symptom scales of the Millon Clinical Multiaxial Inventory (MCMI) for a sample of university undergraduates and (b) the correspondence between MCMI scores from self-report versus scores obtained from knowledgeable others who responded by describing the subject rather than themselves. The MCMI was administered to subjects during their freshman year and then again during their senior year. As in clinical populations, stability estimates in this collegiate sample were greater for the basic personality scales than for the symptom scales. Comparison of the results with those from previous studies further showed that the stability coefficients for the collegiate sample were somewhat lower overall than those from treatment follow-up studies with clinical populations. The results also showed that reasonable agreement between self- and others' ratings was obtained on most MCMI scales. The greatest agreement was found for scales that reflect more observable behaviors and relate to an introversion-extroversion dimension, whereas the least agreement was found for scales related to a psychoticism dimension. Lower levels of agreement were also found for scales having a lower mean proportion of items endorsed.This study was sponsored in part by PHS Grant R01 MH31750-01-6, by PHS Grant 5R01 AA06754-01-03, and by funds from the University of Connecticut Research Foundation and Computer Center.     

Energy, tiredness, and tension effects of a sugar snack versus moderate exercise

After either eating a candy bar or walking briskly for 10 min on 12 selected days, 18 volunteers made systematic self-ratings of their energy, tiredness, and tension feelings for a fixed 2-hr period each day in the context of their normal daily activities. The snacking or walking activity was randomly selected on each test day after completion of a pretest. Results indicated that walking was associated with higher self-rated energy and lower tension significantly more than was snacking. In the walk condition reliable increases in energy and decreases in tension were observed for 2 hr. The sugar snack condition was associated with significantly higher tension after 1 hr, and a pattern of initially increased energy and reduced tiredness, followed 1 hr later by increased tiredness and reduced energy. The results partially support a general conceptual hypothesis that sugar snacking is often motivated by a low-awareness attempt to raise energy. Additionally, the results clarify an apparent conflict between neurochemical research, which indicates that sugar ingestion increases the tendency to sleep, and popular nutrition theory, which indicates that it increases tension.     

Evaluating the influence of time of day on activity engagement in persons with dementia

Dementia is a serious disease affecting a growing number of people. With the onset of dementia comes a decline in social activity engagement that can negatively impact multiple aspects of a person's life. Research suggests that time of day may influence a person with dementia's behavior, including activity engagement, but such research is limited. The purpose of this study was to evaluate the influence of time of day on engagement in activities in persons diagnosed with dementia. An alternating treatments design was used with three participants to measure activity engagement during two times of day, morning and afternoon, and during two activities, a moderately preferred and a low preferred. Results showed no differentiation in engagement between morning and afternoon activities for all three participants, with high levels of engagement during both times of day. For two participants, results showed no differentiation in engagement between moderately preferred and low preferred activities. For one participant, levels of engagement were higher during moderately preferred activities than during low preferred activities.     

The Effect of Perceived Locomotor Constraints on Distance Estimation

Two experiments were conducted to examine the ways in which the visual estimation of distance to a target is affected by constraints perceived to be placed on the subsequent locomotion to the target without vision. We hypothesized that an appraisal of impending effort would play a role in ascertaining the distance to be walked. In Experiment 1, the amount of resistance to walking was variable and unpredictable. One group of subjects performed against relatively low resistance, whereas another group performed against substantially greater resistance. In the low-resistance condition, no significant differences in CE, VE, time to target, or number of steps to target were found between any of the eight combinations of predictable or unpredictable resistances during walking. In the high-resistance condition, however, significant differences were found for CE and number of strides to target when resistance varied unpredictably during walking. Experiment 2 was similar in design but required subjects to walk with combinations of normal or short steps after they had viewed the target knowing only the gait type that would be used to begin locomotion. No differences in CE, VE, or time to target were found between four different combinations of gait type and predictability, under subjectively controlled conditions. When the step constraints were externally imposed, however, differences were found for CE. None of the results from either experiment, in which the number of strides needed to reach the target or the predictability of gait did not change from normal, supported the hypothesis that motor output requirements are necessary in forming a mental representation of the target position that can be used to walk to the target with eyes closed. Whichever locomotor technique was used to walk the estimated distance in these cases, the representation was able to be used independently. When walking mechanics were altered by externally imposed constraints, however, the success at reaching the estimated target position was reduced. These latter results are consistent with those obtained using up, down, and level walking and support the premise that mental representations used in blind walking are linked to the locomotor mechanics afforded by environmental conditions.     

The effects of uncontrollable, unpredictable aversive and appetitive events: Similar effects warrant similar, but not identical, explanations?

Exposure to uncontrollable, unpredictable appetitive events produces a variety of cognitive debilitations and vegetative changes as does exposure to uncontrollable, unpredictable aversive events. Similarities include impaired escape from aversive events, impaired discrimination, finicky consumption, analgesia, and body weight loss. However, in stark contrast, uncontrollable aversive stress causes reduced motor activity where as similar appetitive treatment does not; aversively induced debilitation is causally related to energy regulation, whereas the appetitively induced effects are not. Parallel mechanisms are suggested to explain these effects in terms of a revised anxiety account of the aversive effects, and a frustration account of the appetitive effects. Finally, factors likely to limit important research to resolve the many remaining issues are identified: negative presentation of animal research, political decision making, and ignorance and fear in committees which review the ethics of research. The research reported here was supported by a Sydney University Special Project Grant and Australian Research Council Grants to R.F.S. Job. The paper was completed while the author was supported by a Special Study Leave Grant from the University of Sydney.