The development of path integration: combining estimations of distance and heading

Efficient daily navigation is underpinned by path integration, the mechanism by which we use self-movement information to update our position in space. This process is well-understood in adulthood, but there has been relatively little study of path integration in childhood, leading to an underrepresentation in accounts of navigational development. Previous research has shown that calculation of distance and heading both tend to be less accurate in children as they are in adults, although there have been no studies of the combined calculation of distance and heading that typifies naturalistic path integration. In the present study 5-year-olds and 7-year-olds took part in a triangle-completion task, where they were required to return to the startpoint of a multi-element path using only idiothetic information. Performance was compared to a sample of adult participants, who were found to be more accurate than children on measures of landing error, heading error, and distance error. 7-year-olds were significantly more accurate than 5-year-olds on measures of landing error and heading error, although the difference between groups was much smaller for distance error. All measures were reliably correlated with age, demonstrating a clear development of path integration abilities within the age range tested. Taken together, these data make a strong case for the inclusion of path integration within developmental models of spatial navigational processing

Teaching: Natural or Cultural?

In this chapter I argue that teaching, as we now understand the term, is historically and cross-culturally very rare. It appears to be unnecessary to transmit culture or to socialize children. Children are, on the other hand, primed by evolution to be avid observers, imitators, players and helpers—roles that reveal the profoundly autonomous and self-directed nature of culture acquisition (Lancy in press a). And yet, teaching is ubiquitous throughout the modern world—at least among the middle to upper class segment of the population. This ubiquity has led numerous scholars to argue for the universality and uniqueness of teaching as a characteristically human behavior. The theme of this chapter is that this proposition is unsustainable. Teaching is largely a result of recent cultural changes and the emergence of modern economies, not evolution

Short-interval follow-up mammography versus immediate core biopsy of benign breast lesions: assessment of patient stress.

ObjectiveThe stress experienced by women undergoing surveillance mammography for benign lesions was compared with that experienced by women undergoing core biopsy of benign lesions.Materials and methodsA retrospective survey was mailed to women in whom were diagnosed breast abnormalities that were likely to be benign and that were stable at short-interval follow-up mammography (n = 174) or in whom a core biopsy of the breast was performed, with benign findings (n = 116). The survey included questions about stress related to the diagnostic experience as well as questions about who advised the women of the results of their breast imaging studies and about the information provided.ResultsEighty eligible surveys were received from the women who underwent short-interval follow-up mammography, and 58 surveys were received from the women who underwent biopsies. The self-reported overall stress experienced by the women who underwent core biopsies was significantly greater (p < .001) than that reported by the group who were followed up with mammography. The level of anxiety was not affected by the patient's perception of the probability that the lesion represented carcinoma. We found no significant differences in stress between women who discussed their mammogram results with a radiologist and women who were notified by their primary care provider.ConclusionShort-interval follow-up mammography continues to be acceptable for the evaluation of lesions that are probably benign, even when patient anxiety is considered