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.     

Mood, memory, and social judgments in children

The influence of positive and negative moods on children's recall and recognition memory and impression-formation judgments was investigated in a two-list experimental design. A total of 161 schoolchildren, 8 to 10 years old, were presented with audiovisual information containing positive and negative details about 2 target children. Each presentation was preceded by happy or sad mood manipulations. One day later, the children were again placed in a happy or sad mood, and their recall and recognition memory and impression-formation judgments were assessed. Results showed that memory was better when (a) the children felt happy during encoding, retrieval, or both; (b) the material was incongruent with learning mood; (c) the 2 target characters were encountered in contrasting rather than in matching mood states; and (d) recall mood matched encoding mood. A happy mood increased the extremity of both positive and negative impression-formation judgments. Results are contrasted with experimental data obtained with normal or depressed adults, and implications are considered for contemporary theories of mood effects on cognition and for social-developmental research.     

Encoding and retrieval processes in learning-disabled, head-injured, and nondisabled young adults

Using a multi-trial, free-recall paradigm (Rey Auditory-Verbal Learning Test; Lezak, 1983), the acquisition and retention by learning disabled (LD) young adults with a Halstead Impairment Index less than or equal to 0.3 (low LD) or greater than or equal to 0.4 (high LD) was compared with that of nondisabled and head-injured (HI) young adults. Significant group differences, particularly during the last three acquisition trials, confirmed the effectiveness of this method in revealing subtle learning and retention deficits. Analyses of Trial 1 recall showed group differences in the prerecency but not the recency portion of the serial position curve, thus implicating long-term but not short-term memory differences between the groups. Analyses of pair frequency (Sternberg & Tulving, 1977) data showed that the three clinical groups had difficulty organizing the to-be-learned material for effective retrieval. Following an interpolated task, retention was poorer for the clinical groups than for the nondisabled and varied inversely with the degree of neuropsychological impairment. Finally, during retention, the nondisabled and low LD groups retained and used the list organization established during acquisition whereas the high LD and HI groups did not.     

Preventing Substance Abuse Among American-Indian Adolescents: A Bicultural Competence Skills Approach

Tobacco, alcohol, and drug use are problems for American-Indian people. We reviewed these problems and the explanations for them and described a bicultural competence skills approach for preventing substance abuse with American-Indian adolescents. Data from a study of that approach suggest its efficacy with American-Indian youth. At posttest and a 6-month follow-up, American-Indian subjects who received preventive intervention based on bicultural competence skills concepts improved more than did American-Indian subjects in a no-intervention control condition on measures of substance-use knowledge, attitudes, and interactive skills, and on self-reported rates of tobacco, alcohol, and drug use. Our findings have implications for future substance-abuse prevention research with American-Indian people.