Spontaneous covariations of movement parameters in 5- to 7-year-old boys

The kinematic parameters of to and fro forearm movements in the horizontal plane were investigated in 5- to 7-year-old boys. In one condition, the period of the movements was induced by an acoustic stimulus, while the amplitude was left free. In a second condition, the amplitude of the swing was suggested by a visual frame, but the movement was self-paced. In both conditions, the unconstrained variable (amplitude and period, respectively) was found to covary spontaneously with the constrained variable. The results suggest that, within the age range considered here, motor control processes do not conceive of amplitude and velocity as two independent variables.     

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.