Landmark use by Clark’s nutcrackers (Nucifraga columbiana): influence of disorientation and cue rotation on distance and direction estimates

Many species have been shown to encode multiple sources of information to orient. To examine what kinds of information animals use to locate a goal we manipulated cue rotation, cue availability, and inertial orientation when the food-storing Clark’s nutcracker (Nucifraga columbiana) was searching for a hidden goal in a circular arena. Three groups of birds were used, each with a different goal–landmark distance. As the distance between the goal and the landmark increased, nutcrackers were less accurate in finding the correct direction to the goal than they were at estimating the distance (Experiment 1). To further examine what cues the birds were using to calculate direction, the featural cues within the environment were rotated by 90° and the birds were either oriented when searching (Experiments 2 and 3) or disoriented (Experiment 3). In Experiment 4, all distinctive visual cues were removed (both internal and external to the environment), a novel point of entry was used and the birds were either oriented or disoriented. We found that disorienting the nutcrackers so that they could not use inertial cues did not influence the birds’ total search error. The birds relied heavily but not completely on cues within the environment, as rotating available cues caused them to systematically shift their search behavior. In addition, the birds also relied to some extent on Earth-based cues. These results show the flexible nature of cue use by the Clark’s nutcracker. Our study shows how multiple sources of spatial information may be important for extracting multiple bearings for navigation.     

Usability of liquid crystal displays for research in the temporal characteristics of perception and attention

Recently, the use of liquid crystal displays (LCDs) in computer monitors has increased in popularity. Can LCDs produce results similar to those obtained in cathode-ray tube (CRT) displays in studies of temporal attention and perception tasks? Performance in two tasks (metacontrast masking and attentional blink) was examined using an LCD, a CRT oscilloscope, and a raster scan CRT display. Experiment 1 focused on metacontrast masking where a typical metacontrast function emerged irrespective of monitor type. Experiments 2 and 3 examined whether differences in monitors influence the attentional blink. Again, all displays elicited similar performance profiles for both the attentional blink and the trade-off between identification accuracy of the two targets. Although our results may not generalize to all LCD applications and all experimental paradigms, they indicate that LCDs can reproduce results similar to those found in metacontrast masking and attentional blink studies that were originally identified with CRT displays.     

Belonging – Lucinda Mosher

Book reviewed:
Belonging , Lucinda Mosher, Church Publishing 2005 (1-59627-010-1), 186 pp., pb $15.00     

Gender differences in synchrony: Females in sync during unstructured dyadic conversation

Although previous studies have reported that individual prosocial traits generally enhance synchrony, gender as a social factor was not the subject of focus. The present study examined gender differences in synchrony by conducting three experiments on dyadic unstructured conversations with same-gender strangers. Synchrony was assessed by calculating the cross-wavelet coherence and determining the relative phase. As expected, through the three experiments, the female dyads showed a higher degree of synchrony, compared to the male dyads. Moreover, the conversation type (i.e., structured monologue vs. unstructured dialogue) did not moderate the gender effect (Experiment 2), while synchrony in the female dyads was influenced by the preceding conversation (Experiment 3). In contrast, through the three experiments, the role of the relative phase was unclear. The findings indicate that the social factor, gender, has an impact on synchrony, and that interpersonal sensitivity contributes to synchrony.     

The development of conceptual interests in young children

We conducted a longitudinal analysis of the relative intensity and duration of interests associated with conceptual domains between the ages of 4 and 6 years, respectively. Results indicated a significant portion of preschool children do sustain an interest in conceptual domains during some portion of their childhood. Expected gender differences were found, with boys more likely to express an interest in a conceptual domain than girls. A latent growth curve analysis revealed that the probability of exhibiting a conceptual interest declined as school began, though the rate of that decline was similar for both boys and girls. Potential explanations for the decrease in conceptual interests as school begins are considered.     

Institutional Values of Managed Mental Health Care: Efficiency or Oppression?

The authors suggest that many managed mental health care (MMHC) practices have oppressive effects on members of cultural and ethnic minority groups. They examine the dissonance between institutional practices and cultural traditions that reflect insensitivity and forced conformity, particularly regarding time, pace, and intervention uniformity as applied to clients and commonly required in the MMHC industry. Los autores sugieren que muchas prácticas del cuidado administrado de la salud mental (MMHC, por sus siglas en inglés) tienen efectos opresivos sobre los miembros de grupos de minorías étnicas y culturales. Examinan también la disonancia entre prácticas institucionales y tradiciones culturales que reflejan insensibilidad y una conformidad forzada, sobre todo en lo referente a tiempo, ritmo y uniformidad de intervención tal y como se aplica a clientes y normalmente requeridos por la industria de MMHC.     

Do Conventions Need to Be Common Knowledge?

Do conventions need to be common knowledge in order to work? David Lewis builds this requirement into his definition of a convention. This paper explores the extent to which his approach finds support in the game theory literature. The knowledge formalism developed by Robert Aumann and others militates against Lewis’s approach, because it shows that it is almost impossible for something to become common knowledge in a large society. On the other hand, Ariel Rubinstein’s Email Game suggests that coordinated action is no less hard for rational players without a common knowledge requirement. But an unnecessary simplifying assumption in the Email Game turns out to be doing all the work, and the current paper concludes that common knowledge is better excluded from a definition of the conventions that we use to regulate our daily lives.     

老年人重要社会支持的特点及其与老化态度的关系

采用重要他人和老化态度问卷测查了441名老年人的社会支持和老化态度情况,并且从支持的数量和质量角度以及实际支持和期望支持的角度细致考察了社会支持与老化态度的关系。结果表明：（1）老年人的支持来源符合社会支持层级模式;（2）性别、年龄及受教育水平对老年人社会支持有显著影响;（3）老年人从重要他人那里获得的实际社会支持的质量越高,老化态度越积极。