How emotional auditory stimuli modulate time perception

Emotional and neutral sounds rated for valence and arousal were used to investigate the influence of emotions on timing in reproduction and verbal estimation tasks with durations from 2 s to 6 s. Results revealed an effect of emotion on temporal judgment, with emotional stimuli judged to be longer than neutral ones for a similar arousal level. Within scalar expectancy theory (J. Gibbon, R. Church, & W. Meck, 1984), this suggests that emotion-induced activation generates an increase in pacemaker rate, leading to a longer perceived duration. A further exploration of self-assessed emotional dimensions showed an effect of valence and arousal. Negative sounds were judged to be longer than positive ones, indicating that negative stimuli generate a greater increase of activation. High-arousing stimuli were perceived to be shorter than low-arousing ones. Consistent with attentional models of timing, this seems to reflect a decrease of attention devoted to time, leading to a shorter perceived duration. These effects, robust across the 2 tasks, are limited to short intervals and overall suggest that both activation and attentional processes modulate the timing of emotional events.     

The discrimination of discrete and continuous amounts in African grey parrots (Psittacus erithacus)

A wealth of research in infants and animals demonstrates discrimination of quantities, in some cases nonverbal numerical perception, and even elementary calculation capacities. We investigated the ability of three African grey parrots (Psittacus erithacus) to select the largest amount of food between two sets, either discrete food items (experiment 1) or as volume of a food substance (experiment 2). The two amounts were presented simultaneously and were visible at the time of choice. Parrots were tested several times for all possible combinations between 1 and 5 seeds or 0.2 and 1 ml of food substance. In both conditions, subjects performed above chance for almost all combinations. Accuracy was negatively correlated with the ratio, that is performance improved with greater differences between amounts. Therefore, these results with both individual items and volume discrimination suggest that parrots use an analogue of magnitude, rather than object-file mechanisms to quantify items and substances.     

Leadership Image-Building: After Clinton and Watergate

Leadership images are built collectively by leaders and their relevantconstituencies—elected officials, the news media, and the public. The process of buildingleadership image rests on prior expectations about the leader, policy outputs, the course ofevents, and the disposition of political resources. In building images of leadership, each of thethree constituencies puts more weight on some aspects of image-building than on others: Thepublic sees the president primarily in terms of his previous behavior, the media view thepresident through the lens of immediate events, and other elected officials focus on politicalresources. One of the president's most important resources is his public image. It can helphim to maintain the loyalty of other officials, which in turn contributes to balanced newscoverage, even in times of crisis. President Clinton was able to preserve his public image throughthe impeachment debacle in large part because of low public expectations about his personalmoral behavior and satisfaction with his economic leadership. Conversely, President Nixon wasforced to resign because of high public expectations about his personal probity anddisappointment with his management of the economy.     

Patterns of sedentary behavior among adolescents.

OBJECTIVE: Reducing certain sedentary behaviors (e.g., watching television, using a computer) can be an effective weight loss strategy for youth. Knowledge about whether behaviors cluster together could inform interventions. STUDY DESIGN: Estimates of time spent in 6 sedentary behaviors (watching television, talking on the telephone, using a computer, listening to music, doing homework, reading) were cluster analyzed for a sample of 878 adolescents (52% girls, mean age = 12.7 years, 58% Caucasian). MAIN OUTCOME MEASURES: The clusters were based on the sedentary behaviors listed above and compared on environmental variables (e.g., household rules), psychosocial variables (e.g., self-efficacy, enjoyment), and health behaviors (e.g., physical activity, diet). RESULTS: Four clusters emerged: low sedentary, medium sedentary, selective high sedentary, and high sedentary. Analyses revealed significant cluster differences for gender (p < .002), age (p < .002), body mass index (p < .001), physical activity (p < .01), and fiber intake (p < .01). CONCLUSIONS: Results suggest a limited number of distinct sedentary behavior patterns. Further study is needed to determine how interventions may use cluster membership to target segments of the adolescent population.