Maternal Depressed Mood and Perceptions of Child Temperament

Research has suggested that women who experience postpartum depression are subsequently more likely to perceive their preschool-aged children as temperamentally difficult and maladjusted. However, previous studies have not controlled for the effects of concurrent depression levels on maternal ratings of child temperament or evaluated the accuracy of maternal reports. In the present study we assessed maternal and paternal ratings of child temperament 2 years after subjects had participated in a study of postpartum depression. The findings indicate that correlations between postpartum depression and subsequent child temperament ratings were accounted for statistically by concurrent levels of depression. Although fathers' ratings corroborated some aspects of maternal perceptions, levels of parental agreement were only moderately high. Moreover, discrepancies between the parents' reports were significantly associated with maternal depression, indicating that parental disagreement is more likely when the wife is dysphoric.     

Children's Responses to Entry Failure: Attention Deployment Patterns and Self-Regulation Skills

In this study the authors investigated associations among children's observed responses to failure in an analogue entry situation, their attention deployment patterns, and skills and processes associated with self-regulation. Participants were 54 kindergarten and first-grade students who were either aggressive-rejected or low aggressive-popular based on peer nominations. Inhibitory control predicted the tendency to respond to entry failure by stopping and watching the group's activity. Baseline vagal tone and other-directed attention predicted children's tendency to change entry strategies after failure. Parent-rated attention skills moderated the relation between children's attention deployment patterns during the entry task and their responses to entry failure. Children who engaged in more other-directed attention were less likely to turn to solitary play after entry failure but only if they had high or moderate levels of attentional control. Other-directed attention was related to repeating previous entry bids without modification after entry failure but only when children had high levels of attention problems.     

Executive Function in Young Children and Chimpanzees (Pan troglodytes): Evidence From a Nonverbal Dimensional Change Card Sort Task

In this article the authors compared chimpanzees’ executive function with that of children. They developed a nonverbal dimensional change card sorting task, which indexed the development of executive function. Three pairs of mother and offspring chimpanzees and 30 typically developed 5-year-old children were presented with 2 target stimuli and a test stimulus comprising 2 dimensions (size and shape) on a display; they were required to sort the test stimulus according to 1 dimension (e.g., shape). After 5 consecutive correct trials, the participants had to sort the test stimulus according to the other dimension (e.g., size). The results showed that the chimpanzees often failed to sort the test stimuli according to the first and reversed dimensions. On the other hand, the children were correctly able to use both dimensions. These results indicate that chimpanzees may have less developed executive skills than children.     

Transfer Variables in Tracking Skills

In the present work the effect of two task variables on transfer were studied: shape of the track-circular or triangular; and target speed-constant or variable. One or both of these variables was changed on transfer. Experimental conditions were (a) 10 preshift and 10 post-shift trials, and (b) 20 single-trial alternations of two tasks. 22 groups of 12 Ss each were tested. Condition (a) showed positive transfer with single variable change and zero or negative transfer with simultaneous change in two variables, and condition (b) annulled all transfer effects. Results are discussed in terms of commonality between tasks and receptor and perceptual anticipation.     

Development of Postural Adjustment During Gait Initiation: Kinematic and EMG Analysis

The authors studied the development of postural adjustments associated with the initiation of gait in children by using kinematic and electromyographic (EMG) analysis. Participants (N = 28) included infants with 1-4 and 9-17 months of walking experience, children 4-5 years of age, and adults. Anticipatory postural adjustments (APA) were present in the youngest age groups, including a clear anticipatory lateral tilt of the pelvis and the stance leg, which enabled the child to unload the opposite leg shortly before its swing phase. An anticipatory activation of the hip abductor of the leg in stance phase prior to heel-off was found, suggesting pelvis stabilization. APA did not appear consistently until 4-5 years of age. A decrease in segmental oscillations occurred across the ages, indicating better control of intersegmental coordination in the frontal and sagittal planes during the postural phase of gait initiation. Young walkers presented APA involving movements of both the upper and the lower parts of the body, whereas, like adults, 4- to 5-year-olds were able to laterally shift only the pelvis and the stance leg. The oldest children and the adults also showed lower activation levels of hip and knee muscles but higher activation at the ankle level. Those kinematic and EMG results taken together suggest a clear developmental sequence from an en bloc operation of the body through an articulated operation with maturation, walking experience, or both.     

Sensitivity of Smoothness Measures to Movement Duration,Amplitude, and Arrests

ABSTRACT

Studies of sensory-motor performance, including those concerned with changes because of age, disease, or therapeutic intervention, often use measures based on jerk, the time derivative of acceleration, to quantify smoothness and coordination. However, results have been mixed: some researchers report sensitive discrimination of subtle differences, whereas others fail to find significant differences even when they are obviously present. One reason for this is that different measures have been used with different scaling factors. These measures are sensitive to movement amplitude or duration to different degrees. The authors show that jerk-based measures with dimensions vary counterintuitively with movement smoothness, whereas a dimensionless jerk-based measure properly quantifies common deviations from smooth, coordinated movement.     

Learning Under Conditions of Action Information Feedback

Methodological and empirical issues in research on action information feedback (AIF) are discussed, with particular reference to the procedures and results of Annett (1970). Positioning responses practiced under conditions of AIF training are learned, though generally less well than under terminal IF conditions. Effects obtained as a result of AIF training may be subject to variations in movement extent required, gain and other transformations, frequency, temporal locus, and mode of augmentation, many aspects of which remain to be systematically studied.     

Processing Demands During Movement

Subjects made a speeded stylus movement along a track to a stop and simultaneously performed a simple reaction-time task designed to assess the processing demands of the movement task. Movement task variables were: (a) number of alternative ending positions — either one or two — with the choice executed during movement, and (b) presentation time for the endpoint signals in the two-choice conditions, either prior to movement initiation (immediate) or during movement execution (delay). Processing demands were higher during all movement conditions than in a control condition that did not require movement. Processing demands during execution of the one-and two-choice movement with immediate signals did not differ. However, processing demands during the two-choice movements with delayed signals were higher than demands during the two-choice movement with immediate signals.     

Bimanual and Unimanual Convergent Goal-Directed Movement Times

Three experiments are reported, investigating the effects of using 1 or 2 hands when making convergent low index of difficulty (ID) and visually controlled movements (2 hands meeting together). The experiments involved movements in four different cases—a probe held in the right hand and moved to a target held in the stationary left hand, vice versa of this arrangement, both hands moving with the probe in the right hand and target in the left hand, and vice-versa of this arrangement. Experiments were the standard Fitts’ paradigm, moving a pin into a hole and a low-ID task. In Fitts’ task, 2-hand movements were faster than 1 hand only at higher IDs; this was also the case in the pin-to-hole transfer task and the movement times were lower when the pin was held in the preferred hand. Movements made with low ID showed a small effect of 1- or 2-handed movements, with the effective amplitude of the movement being reduced by about 20% when 2 hands were used.     

The Gender Gap on Wall Street: An Empirical Analysis of Confidence in Investment Decision Making

We attempted to identify the personal characteristics that influence confidence in an investment decision in an experiment administered to 1,359 subjects nationwide. Multiple regression was used to control statistically for variation among subjects and to develop a model of investment decision confidence. The most striking finding was that women had significantly lower confidence in an investment task than men, after controlling for all other relevant variables and characteristics including the amount of the investment decision itself. Familiarity with and present attitude about investing in the stock market, college credit hours in accounting and finance, experience in evaluating common stocks, the current level of the stock market, and the investment decision itself (the amount to be invested) were also found to be significant. Age, value of personal portfolio, years of college, and years of business experience were not significant characteristics.