The development of locomotor coordination: longitudinal change and invariance

Developmental sequence, relative timing, center of gravity, and phase-plane analyses were used to study a minimum of 15 years of longitudinal, filmed data on the development of hopping in 7 children. The developmental sequences revealed common, qualitative changes in the movement of the children, although each child progressed through the changes at his/her own rate. The timing analyses showed that, in the advanced hop, the tightest limb relationships were found within the hopping leg, then between contralateral limbs of the same girdle, and then between legs and arms. Relative-timing calculations revealed (a) intralimb, timing invariances that were present in first attempts to perform the skill at age 3 and remained for 15 years across all developmental levels; (b) emergent, interlimb timings that gradually became invariant; and (c) intra- and interlimb timing showing gradual development over the 15 years. One invariant, the time between landing and deepest knee flexion, is also invariant in the walk and the run (Shapiro, Zernicke, Gregor, & Diestel, 1981). Phase plane analyses indicated that the timing of peak and zero velocities may be the coordinative constant accounting for a relative timing invariance between the two legs. Position of the body's center of gravity may explain the invariant relative time between landing and deepest knee flexion, or the explanation could lie in the "equation of constraint" regulating joint equilibrium points. The data suggest that modeling the developing hop as the evolving interaction of four vibratory systems would be promising.     

Specific forms of facial EMG response index emotions during an interview: from Darwin to the continuous flow hypothesis affect-laden information processing

Previous research has demonstrated that mild negative emotional imagery and unpleasant sensory stimuli lead to greater electromyographic activity over the brow muscle region than mild positive imagery and stimuli, even in the absence of significant changes in visceral and general facial EMG activity. Previous research has not addressed whether electromyographic responses over the brow region are a sensitive and specific index of emotions, however, since a multiplicity of events lead to changes in brow activity. In this research, facial electromyographic and audiovisual recordings were obtained while individuals were interviewed about themselves. Afterwards, individuals were asked to describe what they had been thinking of during specific segments of the interview marked by distinctive electromyographic responses over the brow region in the context of ongoing but stable levels of activity elsewhere in the face. The results are interpreted in terms of a continuous flow hypothesis of affect-laden information processing.     

Perceptual sensitivity to dimensional and similarity relations in free and rule-governed classifications

Two experiments were conducted to investigate the perceptual primacy of dimensional and similarity relations in the stimulus classifications of younger and older subjects. In Experiment 1, 4- and 10-year-olds were given free classifications in which they could group stimuli according to overall similarity or identities in size, color, or orientation. Both age groups classified stimuli most frequently according to identities on separate dimensions. In Experiment 2, 4-year-olds and adults were given free classifications followed by rule-governed classifications which required them to group stimuli according to specific relations. In the free classifications, a majority of subjects in both age groups classified the stimuli most frequently according to identities on separate dimensions. In the rule-governed classifications, both age groups were more accurate when a single separate relation was required for solution than when overall similarity was required. These results support a differential-sensitivity view of perceptual development, which asserts that individuals at all ages primarily perceive and use separate relations.     

Children's perception of certain musical properties: scale and contour

Children's perception of scale and contour in melodies was investigated in five studies. Experimental tasks included judging transposed renditions of melodies (Studies 1 and 3), discriminating between transposed renditions of a melody (Study 2), judging contour-preserving transformations of melodies (Study 4), and judging similarity to a familiar target melody of transformations preserving rhythm or rhythm and contour (Study 5). The first and second studies showed that young children detect key transposition changes even in familiar melodies and they perceive similarity over key transpositions even in unfamiliar melodies. Young children also are sensitive to melodic contour over transformations that preserve it (Study 5), yet they distinguish spontaneously between melodies with the same contour and different intervals (Study 4). The key distance effect reported in the literature did not occur in the tasks of this investigation (Studies 1 and 3), and it may be apparent only for melodies shorter or more impoverished than those used here.     

Effects of Social Demand on Reports of Self-Monitored Blood Glucose in Adolescents with Type 1 Diabetes Mellitus

The purpose of this study was to test the hypothesis that social demand could substantially affect reports of self-monitored blood glucose (BG) in adolescents with insulin-dependent diabetes mellitus. Of 34 patients initially enrolled in the study, 10 were excluded because they did not bring any BG records with them to an outpatient clinic appointment. The remaining 24 patients were randomly assigned to either a low or high social demand condition that provided instructions for monitoring of BG for the week following the appointment. The subjects' BG records were quantified to provide frequency of measurement and mean reported BG for the week prior to and after the clinic visit. Five subjects did not return their BG records for the week following the intervention. The analyses were therefore based on the 19 subjects from whom complete records were obtained. The 12 subjects in the low social demand group and 7 subjects in the high social demand group were equivalent with regard to age, duration of diabetes, socioeconomic status, and glycosylated hemoglobin. Frequency of BG measurement was similar in both groups during both weeks. The mean BG value reported in the week prior to intervention was similar for the groups. However, analyses of the post-intervention BGs revealed that subjects in the low-demand group reported significantly higher BGs compared to pre-intervention and to subjects in the high-demand group. These findings suggest that self-monitoring and reporting of BG is a social behavior that is affected by the demand characteristics of the interpersonal patient-health provider relationship. Because optimal treatment planning for individuals with diabetes requires accurate BG records, care must be taken to interpret them in light of the social demand characteristics associated with clinical assessment.     

BEHAVIORAL MOMENTUM IN THE TREATMENT OF NONCOMPLIANCE

Behavioral momentum refers to the tendency for behavior to persist following a change in environmental conditions. The greater the rate of reinforcement, the greater the behavioral momentum. The intervention for noncompliance consisted of issuing a sequence of commands with which the subject was very likely to comply (i.e., high-probability commands) immediately prior to issuing a low-probability command. In each of five experiments, the high-probability command sequence resulted in a “momentum” of compliant responding that persisted when a low-probability request was issued. Results showed the antecedent high-probability command sequence increased compliance and decreased compliance latency and task duration. “Momentum-like” effects were shown to be distinct from experimenter attention and to depend on the contiguity between the high-probability command sequence and the low-probability command.     

An Investigation of the Professional Travel Environment

In this study the authors compared women's and men's reactions to various professional travel situations. A multivariate analysis of covariance was used to determine the effects of sex, professional role, and years traveling on the perceptions of these travel situations.     

Systemic crisis intervention as a response to adolescent crises: an outcome study

The present study demonstrates the safety and effectiveness of an outpatient program designed to respond to adolescent-precipitated crises by mobilizing and restructuring the family's kinship system. Families of 75 adolescents at risk for hospitalization were followed up to 24 months after treatment with Systemic Crisis Intervention. Measures of offspring and family functioning, suicidal behavior, institutional use, and treatment costs are presented. Results clearly demonstrate the safety, effectiveness, and economic viability of Systemic Crisis Intervention.