The goal of locomotion: Separating the fundamental task from the mechanisms that accomplish it

Human locomotion has been well described but is still not well understood. This is largely true because the observable aspects of locomotion—neuromuscular activity that generates forces and motions—relate to both the task solution and the problem being solved. Identifying the fundamental task achieved in locomotion makes it possible to critically evaluate the motor control strategy used to accomplish the task goal. We contend that the readily observed movements and activities of locomotion should be considered mechanism(s). Our proposal is that the fundamental task of walking and running is analogous to flight, and should be defined in terms of the interaction of the individual’s mass with the medium in which it moves: a low-density fluid for flight, or the supporting substrate for legged locomotion. A rigorous definition of the fundamental task can help identify the constraints and opportunities that influence its solution and guide the selection of appropriate mechanisms to accomplish the task effectively. The results from robotics-based modeling studies have demonstrated how the interaction of the mass and substrate can be optimized, making the goal of movement a defined trajectory of the individual’s mass. We assessed these concepts by evaluating the ground reaction forces generated by an optimization model that satisfies the task but uses none of the mechanisms that are available to the human leg. Then we compared this model to normal human walking. Although it is obvious that the specific task of locomotion changes with a variety of movement challenges, clearly identifying the fundamental task of locomotion puts all other features in an interpretable context.     

Psychopathology of parenthood: Implications for mental health of children

Psychiatric illness among mothers of infants and young children is believed to have serious implications for the child's cognitive and socio-emotional development, and presents a continuing crisis in the provision of reliable parental care: frequent rehospitalizations are disruptive both for the parent-child tie, and for the stability of the family unit. This chapter reviews findings regarding the impact of maternal psychiatric disorders upon the child's development, and intervention programs designed to reduce the impact of these disorders upon both child and family. In addition to considering families in which there is major psychopathology, problems are noted among families in which “an ordinary devoted mother” shows markedly lowered morale, but does not become a part of the mental health system. Findings from a number of innovative intervention programs are summarized in terms of possible next steps in working with these troubled parents and their children.     

Are long compound words identified serially via their constituents? Evidence from an eyemovement-contingent display change study

The processing of two-constituent 12- to 18-letter Finnish compound nouns was studied by using an eye-movement-contingent display change technique. In the display change condition, all but the first 2 letters of the second constituent were replaced by visually similar letters until the eyes moved across an invisible boundary. When the eyes crossed the boundary, the second constituent was changed to its intended form. In the control condition, there was no display change. The frequency of the first constituent was also varied. The major findings were that (1) fixation time on the first constituent was strongly affected by the frequency of the first constituent but was not at all affected by whether the second constituent was visible, but (2) fixation time on the word subsequent to the first constituent's having been left was strongly affected by the display change. These results are most parsimoniously explained by the serial access of the two constituents for these long compound words.     

Judging mens rea: the tension between folk concepts and legal concepts of intentionality

Concepts such as intention, motive, or forethought have generated a great deal of doubt, dispute, and confusion in legal decision making. Here we argue for an empirically based strategy of defining and using such mens rea concepts. Instead of the standard approach of settling these concepts by theoretical argument and the debaters' own intuitions, we rely on social psychological research to determine the meaning and significance of folk concepts concerning mens rea. We demonstrate the reliable and systematic use of people's concept of intentionality, contrast it with the bewildering variety of related legal concepts, and apply the folk model of intentionality to debated distinctions between intention and intentionality, desire and intention, and belief and intention. This folk-conceptual approach promises clarity of mens rea concepts and a reconciliation of the legal and layperson's view of human behavior.     

On scapegoating in therapy groups: a social constructivist and intersubjective outlook.

The social constructs of the group, the group self of an individual member, and the moral order of the group as a whole are described as basic, interrelated concepts essential to our understanding of scapegoating. Two patterns of scapegoating are then introduced: one concerns antagonistic, the other, agonistic relations of scapegoat to scapegoaters. A series of case examples are presented, one involves an advocacy group of socio-cultural "outsiders;" the other three pertain to scapegoating in therapy group settings. The case materials illustrate the meaning and usefulness of an intersubjective/social constructivist perspective on the problem of scapegoating.     

How people explain actions performed by groups and individuals.

The authors explore whether people explain intentional actions performed by groups differently from actions performed by individuals, A theoretical framework is offered that distinguishes between 2 modes of explanation: the agent's reasons (beliefs or desires in light of which the agent decided to act) and causal histories of reasons (CHRs; factors that preceded and brought about the agent's reasons). The authors develop the hypothesis that people use more CHR explanations when explaining group actions than when explaining individual actions. Study 1 demonstrates this asymmetry. Studies 2 and 3 explore 2 necessary conditions for the asymmetry: that the group be perceived as an aggregate of individual actors rather thin as a jointly acting group and that explainers have general information available about the group. Discussion focuses on people's perception of groups as entities and agents.