Rapid error correction during human arm movements: evidence for central monitoring

Studies were made of rapid error correction movements in eight subjects performing a visually guided tracking task involving flexion-extension movements about the elbow. Subjects were required to minimize reaction times in this two-choice task. Errors in initial movement direction occurred in about 3% of the trials. Error correction times (time from initiation to reversal of movement in incorrect direction) ranged from 30-150 ms. The first sing of correction of the error movement was a suppression of the electromyographic (EMG) activity in the muscle producing the error movement. This suppression started as early as 20-40 ms after the initiation of the error-related EMG activity and as much as 50 ms before any overt sign of limb movement. The correction of the error movement was also accompanied by an increase in the drive to the muscle which moved the arm in the correct direction. This increased activity always occurred after the initiation of the error movement. it is concluded that the first step in the error correction, suppression of drive to the muscle producing the error movement, cannot be based on information from the moving limb. It is thus suggested that this earliest response to the error movement is based on central monitoring of the commands for movement.     

On the measurement of storage and retrieval contributions to memory development

We report two free recall experiments and a cued recall experiment in which a new two-stage model was used to obtain numerical measurements of age changes in various aspects of storage and retrieval. The subjects in all three experiments were 7-year-olds (second graders) and 11-year-olds (sixth graders). The major findings in the free recall experiment were that getting a trace into storage posed less of a problem for elementary schoolers than learning how to get it out on test trials, that retrieval development is more rapid during the elementary school years than storage development, and that the superiority of older children's storage and retrieval abilities tends to become more pronounced as learning progresses. A similar pattern of results was obtained under different conditions in the cued recall experiment.     

Cognitive dysfunction in compulsive checkers: Further explorations

Recent evidence suggests a relationship between certain memory deficits and compulsive-checking behavior. The present study explores this relationship in the context of several additional memory capacities not yet investigated. Using the Maudsley Obsessional-Compulsive Inventory and the Everyday Checking Behavior Scale four groups of Ss were identified: (1) frequent checkers, (2) occasional checkers, (3) infrequent checkers and (4) noncheckers. Consistent with previous research, a memory-for-actions task indicated a deficit among compulsive checkers. Furthermore, checking status was found to be negatively related to memory functioning as measured by the Wechsler Memory Scale (WMS) and the Cognitive Failures Questionnaire (CFQ). This memory deficit was most pronounced on the Logical Memory subtest of the WMS. Checkers appear to have difficulty recalling details of meaningfully linked sequences, either presented in narrative form or engaged in personally. Although the reasons for these checking-related deficits are not clear, a complete understanding of checking phenomena will involve an appreciation of the role played by memory deficits.     

Agreement between observers when the categories are not specified in advance

To test the agreement between two observers who categorize a number of objects when the categories have not been specified in advance, Brennan & Light (1974) developed a statistic A′ and suggested a normal approximation for its distribution. In this paper it is shown that this approximation is inadequate particularly when one, or both, of the observers place a fairly equal number of objects in all of their categories. A chi-squared approximation to the distribution of A′ is developed and is shown to work well in a variety of situations. The relative powers of A′ and the ordinary X² test for association are dependent on the type of ‘agreement between the observers’ that is assumed. However a simulation for a fairly general type of agreement indicates that the X² test is more powerful. As the X² test is also much easier to apply, it would seem preferable in most situations.     

Family boundary ambiguity: a new variable in family stress theory

The variable, degree of family boundary ambiguity, is increasingly being used in family research to describe and predict the effects of family membership loss and change over time. Boundary ambiguity is defined as the family not knowing who is in and who is out of the system. The family may perceive a physically absent member as psychologically present or a physically present member as psychologically absent. In either case, the family boundary is ambiguous. This review is presented to clarify the meaning of boundary ambiguity and to explore its scope and application as a variable. We focus here on (a) the process of theory development, inductive and deductive, by which the construct of boundary ambiguity was identified and validated as a continuous variable within family stress theory; (b) the historical antecedents of the construct; and (c) the interrelationships of the variable with other factors related to stressed families.     

Resource theory and power in families: life cycle considerations

We begin our discussion by outlining the usefulness of "resource theory" as a theoretical framework for the study of family power. This framework is then used to analyze changes in the balance of power between elderly parents and their middle-age children. With respect to intergenerational power relationships, we argue that the autonomy of elderly parents has increased, but their power and influence over adult children has decreased. This trend is likely to continue in coming decades. Resource theory is then utilized to analyze changes in marital power relationships as couples age. Most studies of power relationships between elderly spouses have an important limitation--they tend to reflect yesterday's definitions of male and female roles. Recent changes in these roles may significantly alter the social meanings of aging for both men and women in coming years.     

The resurrection of a magical reality: treatment of functional migraine in a child

A magical world view and logic were used in the treatment of a 10-year-old girl who was referred because of suicidal threats due to migrainous pain. The treatment consisted of a one-session intervention with three-week, six-month, and one-year follow-up indicating elimination of migraine. Within a strategic family therapy, a magical ritual was prescribed that derived from the preoperational logic explicated by Piaget and from the healing practices described in anthropological studies. Such a ritual casts the symptom in a different context, alters the meaning of migraine to the family system, and leads to different interactional patterns. Piaget's theory and anthropological data are discussed as sources of a magical world view to help families and children disengage from a symptomatic system of interactions.     

Dialectical Metatheory in Family Therapy

This paper addresses the controversy in family therapy over basic philosophical issues in terms of a historical opposition between demonstrative and dialectical metatheories. It argues that advances in family therapy are indicative of the growing prominence of dialectical forms of understanding in the social sciences. Several family therapy concepts are explored as representative of the dialectical categories of motion, form, relationship, and transformation.     

The Empirical Evaluation of Family Therapy Training

This paper presents the results of the first comprehensive and empirical evaluation of a family therapy training program. Focusing on the first year of a two-year training program, the study found significant changes in the clinical conceptualizations and in-therapy verbal behaviors of a group of trainees. Additionally, this study involved the development and/or first use of various research instruments and procedures that can be used to facilitate further research on family therapy training.