Call recognition in chicks of the Australian brush-turkey (Alectura lathami)

Most birds rely on imprinting and experience with conspecifics to learn species-specific recognition cues. Australian brush-turkeys (Alectura lathami) do not imprint and form no bonds with parents. They hatch asynchronously, disperse widely and meet juvenile conspecifics at an unpredictable age. Nevertheless, in captivity, hatchlings respond to other chicks. A recent study, which involved the use of robotic models, found that chicks prefer to approach robots that emit specific visual cues. Here, we evaluated their response to acoustic cues, which usually play an important role in avian social cognition. However, in simultaneous choice tests, neither 2-day-old nor 9-day-old chicks preferred the choice arm with playback of either chick or adult conspecific calls over the arm containing a silent loudspeaker. Chicks of both age classes, however, scanned their surroundings more during chick playback, and the response was thus consistent in younger and older chicks. We also presented the chicks with robotic models, either with or without playback of chick calls. They did not approach the calling robot more than they did the silent robot, indicating that the combination of visual and acoustic cues does not evoke a stronger response. These results will allow further comparison with species that face similar cognitive demands in the wild, such as brood parasites. Such a comparative approach, which is the focus of cognitive ecology, will enable us to further analyse the evolution and adaptive value of species recognition abilities.     

Reasons for suicide attempts and nonsuicidal self-injury in women with borderline personality disorder

Self-reported reasons for suicide attempts and nonsuicidal self-injury were examined using the Parasuicide History Interview within a sample of chronically suicidal women meeting criteria for borderline personality disorder (N = 75). Overall, reasons given for suicide attempts differed from reasons for nonsuicidal self-injury. Nonsuicidal acts were more often reported as intended to express anger, punish oneself, generate normal feelings, and distract oneself, whereas suicide attempts were more often reported as intended to make others better off. Almost all participants reported that both types of parasuicide were intended to relieve negative emotions. It is likely that suicidal and nonsuicidal parasuicide have multiple intents and functions.     

Work time,work interference with family,and psychological distress

Despite public concern about time pressures experienced by working parents, few scholars have explicitly examined the effects of work time on work-family conflict. The authors developed and tested a model of the predictors of work time and the relationships between time, work interference with family (WIF). and psychological distress. Survey data came from 513 employees in a Fortune 500 company. As predicted, several work and family characteristics were significantly related to work time. In addition, work time was significantly, positively related to WIF, which in turn was significantly, negatively related to distress. The results suggest that work time fully or partially mediates the effects of many work and family characteristics on WIF.     

Are performance predictions for text based on ease of processing?

In 4 experiments, the authors evaluated the hypothesis that performance predictions for text are based on ease of processing. In each experiment, participants read texts, predicted their performance for each one, and then were tested. Ease of processing was manipulated by having participants read texts that varied in coherence. Coherence was varied by manipulating causal relatedness across sentence pairs (Experiments 1 and 2) and by altering the structure of sentences within paragraphs (Experiment 3). In these experiments, prediction magnitudes increased as coherence increased, suggesting that predictions were based on processing ease. In Experiment 4, prediction magnitudes were greater for intact paragraphs than for paragraphs with letters deleted from some of the words. Discussion focuses on resolving apparent inconsistencies in the literature concerning whether processing ease influences performance predictions.     

Pauses and durations exhibit a serial position effect

This article reports evidence of two kinds of serial position effects in immediate serial recall: One involves interresponse pauses, and the other response durations. In forward and backward recall, responding was faster at initial and final positions than at center positions, exhibiting a bow-shaped function relative to serial position. These data were obtained in a spoken recall study in which ungrouped lists of four to six words and postcuing of recall direction were used. The pause pattern is consistent with several models of serial memory, including a distinctiveness model (Brown, Neath, & Chater, 2002) and a version of the ACT—R model augmented with a spontaneous grouping strategy (Maybery, Parmentier, & Jones, 2002). The duration pattern suggests that response articulation depends on the processing context, rather than being modular.     

Childhood Temperament and Family Environment as Predictors of Internalizing and Externalizing Trajectories From Ages 5 to 17

Childhood temperament and family environment have been shown to predict internalizing and externalizing behavior; however, less is known about how temperament and family environment interact to predict changes in problem behavior. We conducted latent growth curve modeling on a sample assessed at ages 5, 7, 10, 14, and 17 (N = 337). Externalizing behavior decreased over time for both sexes, and internalizing behavior increased over time for girls only. Two childhood variables (fear/shyness and maternal depression) predicted boys' and girls' age-17 internalizing behavior, harsh discipline uniquely predicted boys' age-17 internalizing behavior, and maternal depression and lower family income uniquely predicted increases in girls' internalizing behavior. For externalizing behavior, an array of temperament, family environment, and Temperament × Family Environment variables predicted age-17 behavior for both sexes. Sex differences were present in the prediction of externalizing slopes, with maternal depression predicting increases in boys' externalizing behavior only when impulsivity was low, and harsh discipline predicting increases in girls' externalizing behavior only when impulsivity was high or when fear/shyness was low.     

Self-motion perception during locomotor recalibration: more than meets the eye

Do locomotor aftereffects depend specifically on visual feedback? In 7 experiments, 116 college students were tested, with closed eyes, at stationary running or at walking to a previewed target after adaptation, with closed eyes, to treadmill locomotion. Subjects showed faster inadvertent drift during stationary running and increased distance (overshoot) when walking to a target. Overshoot seemed to saturate (i.e., reach a ceiling) at 17% after as little as 1 min of adaptation. Sidestepping at test reduced overshoot, suggesting motor specificity. But inadvertent drift effects were decreased if the eyes were open and the treadmill was drawn through the environment during adaptation, indicating that these effects involve self-motion perception. Differences in expression of inadvertent drift and of overshoot after adaptation to treadmill locomotion may have been due to different sets of ancillary cues available for the 2 tasks. Self-motion perception is multimodal.     

Semantic feature knowledge and picture naming in dementia of Alzheimer's type: a new approach

This study addresses continuing controversies concerning the nature of semantic impairment in early dementia of the Alzheimer type (DAT), and the relationship between conceptual knowledge and picture naming. A series of analyses of fine-grained feature knowledge data show that: (1) distinctive features of concepts were more vulnerable than shared; (2) the amount of attribute knowledge about a concept was associated reliably, and in a graded fashion, with the ability to name a picture of that item; (3) sensory features were differentially important in naming; and (4) the degree of disruption to different types of attribute knowledge did not vary between items from living and nonliving domains. These findings are discussed in the context of contemporary cognitive and computational models of semantic memory organisation.     

Motivation influences the underestimation of cumulative risk

Past research has shown that people typically underestimate the cumulative risk of events. This effect has mainly been interpreted as resulting from the use of cognitive heuristics and judgment strategies, such as availability or anchoring and adjustment. The authors suggest that motivational processes can be an additional force in the generation of cumulative risk estimates. Using an experimental design, Study 1 shows that people underestimate the cumulative risk of infection with sexually transmitted diseases of appealing prospective sexual partners by using risk-irrelevant information for their judgment. Using a correlational design, Study 2 demonstrates that people underestimate the cumulative risk of being infected with a sexually transmitted disease and that commitment to the present partner is directly related to a low cumulative risk estimate as well as indirectly through its effect on the perceived risk of the present partner. Together, the two studies demonstrate that motivation influences the underestimation of cumulative risk.     

The prediction of above-average participation in volunteerism: a test of the theory of planned behavior and the volunteers functions inventory in older Australian adults

In the present prospective study of 81 older volunteers from a nonprofit organization in Australia, the authors compared the predictive utility of I. Ajzen's (1988) theory of planned behavior with that of E. G. Clary and M. Snyder's (1991) functional approach to volunteering. The authors mailed questionnaires to 385 volunteers in two waves of data collection. The first wave measured theory-of-planned-behavior variables and functional-approach variables. The second wave measured self-reported volunteering behavior for the previous month. Regression analyses supported both the theory of planned behavior and the functional approach; the theory of planned behavior accounted for a significantly larger proportion of variance in above-average participation in self-reported volunteerism. The findings of the present study provided some support for both the theory of planned behavior and the functional approach as models of self-reported volunteerism.