The width of the auditory filter in children

Because young children have poorer auditory temporal resolution than older children, they ought to have, according to the inverse relation between temporal and frequency resolution, narrower auditory filters than older children. Therefore, the auditory filters of two 6-year-olds, two 10-year-olds, and two adults were measured by having them detect a 400-ms sinusoid (500, 1000, or 3000 Hz) centered in a spectral notch in a band of noise. The signal power for 71% correct was determined as a function of notch width with the two-alternative, forced-choice procedure. The principal results showed a significant decrease in signal power with age and a significant interaction between age and notch width. The best-fitting parameters of a model of the auditory filter showed that the filter was significantly wider for the 6-year-olds than for the 10-year-olds or the adults.     

Development of differences in response latencies to right and left visual fields

Robust lateralization developed in right-handed adults who were asked to judge letter pairs as "same" or "different" during 4608 trials. By the end of the first two blocks (768 trials) "same" responses were favored when presented in the RVF (transmitted directly to the left hemisphere) and "different" responses were favored when presented in the LVF (transmitted direction to the right hemisphere). This gradually reversed over sessions with "same" responses becoming faster for letters presented in the LVF, and "different" responses becoming faster for stimuli presented in the RVF. The laterality acquired under these conditions was cumulative and reproducible, appeared in all 16 subjects, and was preserved between sessions a week apart. The data suggest that laterality is a flexible and reversible characteristic of the human brain even when stimulus and task remain constant.     

In Vivo Hippocampal Acetylcholine Release During Exposure to Acute Stress

Hippocampal extracellular acetylcholine (ACh) and choline levels were evaluated using in vivo microdialysis in male Fischer 344 rats before, during, and following an 80-min exposure to two different stress conditions. Measurements were taken in rats restrained and immersed in a water bath containing either 37 degreesC (normothermic-restraint) or 20 degreesC (cold-restraint) water. Results were compared to normothermic-freely-moving rats. Cold-restrained rats displayed decreased ACh levels during cold exposure relative to both normothermic-restrained and normothermic-freely-moving rats. By the end of the cold exposure period and following removal from cold, ACh levels had returned to near-baseline values. Normothermic-restrained rats had levels similar to those of normothermic-freely-moving rats, except for a marked increase in ACh following removal from restraint. Cold-restrained rats displayed a gradual elevation in choline levels during cold stress, followed by a gradual decline after stress termination, whereas both normothermic-restrained and normothermic-freely-moving rats displayed gradual decreases during the microdialysis session. These findings demonstrate that central cholinergic neurotransmission can be altered by the application of, and removal from, acute stressors. In addition, the results suggest a possible relationship between the magnitudes of both the stressor and its cholinergic consequences.     

Gratitude and depressive symptoms: the role of positive reframing and positive emotion

Eight studies (N=2,973) tested the theory that gratitude is related to fewer depressive symptoms through positive reframing and positive emotion. Study 1 found a direct path between gratitude and depressive symptoms. Studies 2-5 demonstrated that positive reframing mediated the relationship between gratitude and depressive symptoms. Studies 6-7 showed that positive emotion mediated the relationship between gratitude and depressive symptoms. Study 8 found that positive reframing and positive emotion simultaneously mediated the relationship between gratitude and depressive symptoms. In sum, these eight studies demonstrate that gratitude is related to fewer depressive symptoms, with positive reframing and positive emotion serving as mechanisms that account for this relationship.     

Mortality salience increases adherence to salient norms and values

Four studies indicate that mortality salience increases adherence to social norms and values, but only when cultural norms and values are salient. In Study 1, mortality salience coupled with a reminder about cultural values of egalitarianism reduced prejudice toward Blacks among non-Black participants. In Studies 2 through 4, a mortality salience induction (e.g., walking through a cemetery) increased self-reported and actual helping behavior only when the cultural value of helping was salient. These results suggest that people may adhere to norms and values so as to manage awareness of death.     

Bridging Science and Practice in Violence Prevention: Addressing Ten Key Challenges

This article illustrates ideas for bridging science and practice generated during the Division of Violence Prevention's (DVP) dissemination/implementation planning process. The difficulty of moving what is known about what works into broader use is near universal, and this planning process pushed us to look beyond the common explanations (e.g., providers were resistant/unwilling to change practice) and think about the multiple layers and systems involved. As part of this planning process, the Interactive Systems Framework for Dissemination and Implementation (ISF) was developed and then applied to the fields of child maltreatment and youth violence prevention. Challenges for each of the three systems in the ISF are discussed as well as and action and research ideas to address the challenges. Also described are actions taken by DVP in response to the planning process to illustrate how a funder can use the ISF to bridge science and practice.     

What's so funny about not having money? The effects of power on laughter

Two studies tested the hypothesis that occupying a position of low power increases the likelihood of laughter, presumably as a means of gaining friends and supporters. In Study 1, participants laughed more at an interviewer's jokes when the interviewer controlled their cash rewards than in the absence of monetary contingencies. Study 2 found that low-power participants (manipulated again by expecting that someone else would decide their cash rewards) laughed more than high-power participants even when they were alone. Low power also increased laughing at a fellow low-power coworker. These findings suggest that low power motivates interest in making friends and hence increases behaviors that promote social bonding.     

Newborn categorization of vowel‐like sounds

While there are many theories of the development of speech perception, there are few data on speech perception in human newborns. This paper examines the manner in which newborns responded to a set of stimuli that define one surface of the adult vowel space. Experiment 1 used a preferential listening/habituation paradigm to discover how newborns divide that vowel space. Results indicated that there were zones of high preference flanked by zones of low preference. The zones of high preference approximately corresponded to areas where adults readily identify vowels. Experiment 2 presented newborns with pairs of vowels from the zones found in Experiment 1. One member of each pair was the most preferred vowel from a zone, and the other member was the least preferred vowel from the adjacent zone of low preference. The pattern of preference was preserved in Experiment 2. However, a comparison of Experiments 1 and 2 indicated that habituation had occurred in Experiment 1. Experiment 3 tested the hypothesis that the habituation seen in Experiment 1 was due to processes of categorization, by using a familiarization preference paradigm. The results supported the hypothesis that newborns categorized the vowel space in an adult‐like manner, with vowels perceived as relatively good or poor exemplars of a vowel category.