On optimal smoothing and derivative estimation from noisy displacement data in biomechanics

Estimating derivatives from noisy displacement data is a notoriously ill-posed problem in signal processing and biomechanics. Following the work of Wood and Jennings (1978) and Hatze (1979, 1981), the present paper describes the use of optimally regularized, natural quintic splines for estimating smoothed positions, velocities, and accelerations from equidistantly sampled, noisy position measurements. It appears that the nature of the boundary conditions of the data is of some importance, since various algorithms used hitherto result in artefacts throughout the data if the true derivatives at the record ends differ significantly from zero. Natural quintic splines do not suffer from this disadvantage below the third derivative.The ill-posed character of movement analysis has some interesting implications for movement synthesis and optimization, similar to the indeterminacy of muscular co-contraction from merely external, biomechanical measurements.     

The universal nature of human intelligence: Evidence from games

Mentally retarded individuals have relatively greater difficulty in dealing with strategic games and puzzles than with many other tasks. Consequently, it is of interest to find that strategic games have been played since ancient times, are played throughout the world, and that players who excel are frequently considered wise. Hidden within the more obvious differences between cultures, strategic games are an invariant expression of certain universal intellectual traits.     

A note on general intelligence and the MA deviation concept

Restraints are imposed on the fullest emergence of g when subjects of equal chronological age are drawn from a restricted range of intelligence, or when groups representing different levels of IQ are factor-analyzed separately. Realistically, persons representing the extremes of intelligence cannot be included in the same study unless they are approximately equated on mental age (MA), in which case the relative performances of the extreme groups can provide useful information about the nature of intelligence. Comparisons of less extreme groups (e.g., average vs intellectually retarded or gifted) are also informative, particularly when attention is given to the types of tasks on which the retarded show the largest MA lag and the gifted show the largest MA acceleration.     

Recognition and treatment of incestuous families

Incest is a major mental health problem, in terms of both prevalence and morbidity. Father-daughter incest constitutes the majority of reported cases. The possibility of incest should be considered in a family which includes a violent father, a disabled mother, a child in an adult maternal role, or an acting out adolescent girl. Intervention requires recognition of the criminal and addictive aspects of the father's behavior. Active cooperation between mental health professionals and mandated child protective and law enforcement agencies is necessary for effective treatment. Group therapy and affiliated self-help programs appear to be the treatment modality of choice. Rehabilitation of the family is based upon restoration of the mother-daughter bond as a guarantee of safety for the child.     

Developmental phases of sleep and motor behaviour in a cat mother-infant system: a time-lapse video approach

The evolution of sleep patterns in developing kittens was studied using time-lapse video technology and direct observation. The duration, frequency, and onset of the behavioural states and interactions of the cats were analyzed and then organized into phases that represent major changes in developmental structure during the first 6 weeks of kitten life. We have demonstrated that the kittens began exhibiting adult bi-cyclic sleep patterns on approximately Day 30 of development. During the 10-day period that preceded this consolidation of sleep pattern, REM sleep decreased by half, with a reciprocal increase in NREM sleep. These changes were coincident with an increase in kitten patterned motor behaviour and an increase in stimulation of the kittens by the mother during her bi-cyclic active periods.     

Jivacide,Zombies and Jivanmuktas: the meaning of life in the Bhagavad Gitā

In discussing the meaning of life in the Bhagavad Gitā two obvious questions arise: first, what is the meaning of ‘the meaning of life'?, and second, how does that meaning apply to the Bhagavad Gitā? In Part I of this brief paper I will attempt to answer the first question by focusing on one of the common meanings of that phrase; in Part II, I will apply that very common meaning to the Bhagavad Gitā; and in the third and final part, I will point to a puzzle, the paradox of the jivanmukta, that would seem to follow from the discussion in the first two parts of this paper.

My own feeling is that the concept of ‘the meaning of life’ is a Western invention [1]. This being so, perhaps it would be wise to probe for that concept and its meaning among Western authors. We turn first, then, to one ancient writer, Aristotle of Stagira, and conclude Part I with a modern writer also concerned with the meaning of life, Albert Camus.     

Mentally retarded individuals outperform college graduates in judging the nonconservation of space and perimeter

Most adults of average and superior intelligence incorrectly assume that in a two dimensional figure two attributes, area, and perimeter, are locked in a fixed relationship such that if one remains unchanged so does the other. Consequently, when they correctly conserve one attribute during shape transformation, they incorrectly conserve the other. Mentally retarded individuals assume no such fixed relationship but depend exclusively on perceptual information. Although this dependence adversely effects their judgment of conservation, it allows them to correctly judge the changed state of the nonconserved attribute.     

Tower of Hanoi performance of retarded young adults and nonretarded children as a function of solution length and goal state

Three experiments were conducted with the Tower of Hanoi task to assess problem solving ability in 6-, 7-, 8-, and 10-year-old nonretarded children and mentally retarded young adults of varying maturational ages. In Experiment 1 we gradually reduced the number of moves required for solution until subjects could solve the 3-disk tower-ending problem. Although all groups experienced difficulty with the standard 7-move problem, all but the trainable retarded group readily solved the 6-move problem. The trainable group did not reach a comparable level of success until the 4-move problem. On the 7-move problem the retarded groups performed at the level of nonretarded groups that were maturationally $\text{1}\text{1}\text{2}$ to 3 years younger. An analysis of first moves indicated that subject groups differed in the strategies they used to solve the problems. In Experiment 2, practice effects were ruled out as a source of the superior performance on the 6- than on the 7-move problem. In Experiment 3, 7- and 10-year-old nonretarded children and mentally retarded young adults did not differ on 5-move problems in which configuration of the goal states was varied. A comparison of all 5-move problems judged to have the same depth of search requirements indicated that the tower-ending problems were significantly easier to solve than the partial-tower-ending problems, which in turn were easier than the flat-ending problems. A limited depth of search capacity sets boundaries on the use of sophisticated strategies and, to a large extent, accounts for the retarded groups' maturational lag.     

Cognitive styles in the development of medical careers

Recent research has shown that academic choice and achievement may be partly a function of the student's standing on the field-dependence-independence cognitive-style dimension. The results of two longitudinal studies suggest that information about field dependence-independence may be of value for student guidance in the medical setting. The first, a study of college undergraduates who early expressed an interest in medicine, showed that these cognitive styles play a discernible role in determining who will eventually enter medical school. The second, a study of medical students, showed that field-dependent and field-independent students subsequently tend to choose different medical specialties. These results are consistent with cognitive-style theory, which proposes that field-independent people will choose vocations that require cognitive restructuring skills, whereas field-dependent people will choose vocations that require greater social-interpersonal involvement.