Effect of Age and Gender in the Control of Elbow Flexion Movements

In previous studies of rapid elbow movements in young healthy men, characteristic task-dependent changes in the patterns of muscle activation when movement speed or distance was varied have been reported. In the present study, the authors investigated whether age or gender is associated with changes in the patterns of muscle activity previously reported in young men. Arm movements of 10 healthy older and 10 healthy younger participants (5 men and 5 women in each group) were studied. Surface electromyograms (EMGs) from agonist (biceps) and antagonist (triceps) muscles, kinematic and kinetic parameters, as well as anthropometric and strength measures were recorded. All 4 groups of participants showed similar task- (distance or speed) dependent changes in biphasic EMG activity. Similar modulation of the initial rate of rise of the EMG, integrated agonist and antagonist EMG activity, as well as their relative timing were observed in all 4 groups. Those results suggest that older individuals of both genders retain the control strategies for elbow movements used by young individuals. Despite the qualitative similarities in the patterns of muscle activation, the men moved more quickly than the women, and younger participants moved more quickly than older participants. Those performance differences could not be explained in terms of differences in body size and strength alone.     

Packaging of healthy and unhealthy food products for children and parents: The relative influence of licensed characters and brand names

• Using a sample of 43 7–8‐year olds and their parents, we examined the extent to which children's judgments about food products are influenced by the same factors as their parents'. The factors manipulated were healthiness of product, brand name familiarity, and use of licensed cartoon characters (children) or celebrity endorsers (parents). Brand name familiarity was a more important factor than familiar cartoon characters or celebrity endorsers on food product evaluations. Parents and girls but not boys rated healthy products higher than unhealthy ones (e.g., breakfast cereal vs. pastries). However, parents placed greater weight on healthiness when choosing products for themselves than when choosing for their children. Discussion focuses on the promotion of healthy eating habits in children.

Copyright © 2010 John Wiley & Sons, Ltd.     

Cultural influences on neural substrates of attentional control

Behavioral research has shown that people from Western cultural contexts perform better on tasks emphasizing independent (absolute) dimensions than on tasks emphasizing interdependent (relative) dimensions, whereas the reverse is true for people from East Asian contexts. We assessed functional magnetic resonance imaging responses during performance of simple visuospatial tasks in which participants made absolute judgments (ignoring visual context) or relative judgments (taking visual context into account). In each group, activation in frontal and parietal brain regions known to be associated with attentional control was greater during culturally nonpreferred judgments than during culturally preferred judgments. Also, within each group, activation differences in these regions correlated strongly with scores on questionnaires measuring individual differences in culture-typical identity. Thus, the cultural background of an individual and the degree to which the individual endorses cultural values moderate activation in brain networks engaged during even simple visual and attentional tasks.     

A causal model theory of the meaning of cause, enable, and prevent

The verbs cause , enable , and prevent express beliefs about the way the world works. We offer a theory of their meaning in terms of the structure of those beliefs expressed using qualitative properties of causal models, a graphical framework for representing causal structure. We propose that these verbs refer to a causal model relevant to a discourse and that "A causes B" expresses the belief that the causal model includes a link from A to B. "A enables/allows B" entails that the model includes a link from A to B, that A represents a category of events necessary for B, and that an alternative cause of B exists. "A prevents B" entails that the model includes a link from A to B and that A reduces the likelihood of B. This theory is able to account for the results of four experiments as well as a variety of existing data on human reasoning.     

Speaking without seeing,or the effect of interviewer absence on interviewee disclosure time

The results of the present study confirmed earlier findings that the elimination of the usual face-to-face confrontation between interviewer and interviewee enhances disclosure time in relation to intimate questions. By unconfounding speaking time and pausing time, the present research demonstrated that the facilitating effect of an interviewer's absence is not simply an artifact of increased latencies and silent pauses within responses. The earlier findings were extended by manipulating the intimacy level of questions asked of subjects in the context of a gender-balanced design.     

Effects of mutual invisibility and topical intimacy on verbal fluency in dyadic communication

The mutual reduction of visual feedback, which in this study did not interfere with the synchronization of turns, reduced the productivity levels and increased the silent pauses of female speakers, even though it had no effect on their subjective discomfort, anxiety, and ease of communication self-ratings. The same reduction of visual feedback, which was achieved by seating the participants back-to-back rather than face-to-face, caused male speakers to feel anxious and uncomfortable and reduced the duration of their silent pauses, but only in samegender dyads. These findings are explained in terms of previously noted gender differences in the need for visual feedback and in the anxiety-arousing effects of back-to-back interactions. Intimate communications, on the part of both male and female speakers, were associated with a slow pacing of speech but not with a decrease in productivity level, independently of the seating arrangement. These findings are interpreted in terms of the self-monitoring and self-censoring that is usually associated with the communication of intimate messages.