Thinking around the corner: the development of planning abilities

The ability to plan and search ahead is essential for problem solving in most situations in everyday life. To investigate the development of planning and related processes, a sample of four- and five-year-old children was examined in a variant of the Tower of London, a frequently used neuropsychological assessment tool of planning abilities. The applied problems either required searching ahead for optimal solution or were solvable by pure step-by-step forward processing. Furthermore, the ambiguity of subgoal ordering was varied.Results revealed an age-related effect of search depth: the four-year olds’ planning accuracy was particularly decreased in problems demanding search ahead, while five-year olds mastered both problem types equally well. Interestingly, this interaction between age and search depth could not be accounted for by measures of working memory and inhibition. Differential effects of age were also found for subgoal ordering with respect to initial planning and movement execution times. In sum, planning abilities showed considerable development during late kindergarten age that appeared to be specifically associated with the integration and back-validation of the anticipated consequences of internally modeled actions. The present study demonstrates that a careful consideration of problem structure may greatly enhance the insights gained from the application of a routinely used assessment tool, the Tower of London. This may be especially advantageous when addressing specific subpopulations such as children or clinical samples.     

The curious incident of the photo that was accused of being false: issues of domain specificity in development, autism, and brain imaging

We resume an exchange of ideas with Uta Frith that started before the turn of the century. The curious incident responsible for this exchange was the finding that children with autism fail tests of false belief, while they pass Zaitchik's (1990) photograph task (Leekam & Perner, 1991). This finding led to the conclusion that children with autism have a domain-specific impairment in Theory of Mind (mental representations), because the photograph task and the false-belief task are structurally equivalent except for the nonmental character of photographs. In this paper we argue that the false-belief task and the false-photograph task are not structurally equivalent and are not empirically associated. Instead a truly structurally equivalent task is the false-sign task. Performance on this task is strongly associated with the false-belief task. A version of this task, the misleading-signal task, also poses severe problems for children with autism (Bowler, Briskman, Gurvidi, & Fornells-Ambrojo, 2005). These new findings therefore challenge the earlier interpretation of a domain-specific difficulty in inferring mental states and suggest that children with autism also have difficulty understanding misleading nonmental objects. Brain imaging data using false-belief, "false"-photo, and false-sign scenarios provide further supporting evidence for our conclusions.     

Social representations of organ donors and non‐donors

This paper illustrates the empirical investigation of social representations by means of photographs as stimulus material and the technique of correspondence analysis to study the resulting data. The research was part of a campaign carried out to promote organ donation in Malta. The study tries to find out whether a public communication campaign could change perceptions. Five focus groups were held before the campaign and another five, two months after the campaign. Part of the data collected through these focus groups was analysed using correspondence analysis. The results showed that before the campaign, donors were generally perceived to be either young or important people or public personalities. After the campaign, donors were perceived more to be ordinary family people, educated, generous and religious. On the other hand, before the campaign, non‐donors were seen as conservative, uncouth and uncaring, whereas after the campaign non‐donors were generally perceived to be older, uninformed and uneducated people. Copyright © 2005 John Wiley & Sons, Ltd.     

Misinformation and unexpected change: Testing the development of epistemic-state attribution

Summary Children's ability to infer a person's ignorance and false belief was tested in two stories which differed as to the relative ease for making these inferences. In the Unexpected Change story ignorance could be directly inferred from the emphasized fact that the target character had not witnessed the change, while false belief required the additional inference that the character would assume that things would stay as they had been initially. In the Misinformation Story false belief was made directly accessible by the content of a false message, while ignorance was not directly indicated by absence of information. It needed to be inferred from the fact that the available information was misleading. Results from 3- and 4-year-old Austrian and English children showed that manipulation of inferential difficulty did not affect their ability to make epistemic state attribution. In both stories children found it easier to attribute ignorance than false belief. To integrate this finding in the larger developmental context we suggest that children younger than 4 years find it difficult to distinguish between knowledge and ignorance because they do not understand the role of informational access in the formation of knowledge and they fail in false-belief attribution because they do not understand that incompatible truth values can be assigned to propositions.     

DEWEX: A system for designing and conducting Web-based experiments

DEWEX is a server-based environment for developing Web-based experiments. It provides many features for creating and running complex experimental designs on a local server. It is freeware and allows for both using default features, for which only text input is necessary, and easy configurations that can be set up by the experimenter. The tool also provides log files on the local server that can be interpreted and analyzed very easily. As an illustration of how DEWEX can be used, a recent study is presented that demonstrates the system’s most important features. This study investigated learning from multiple hypertext sources and shows the influences of task, source of information, and hypertext presentation format on the construction of mental representations of a hypertext about a historical event.