Biomedical subjects

Tim P German

Publications and source records attributed to Tim P German.

8 recordsLinked to original sources

PubMed2006

Conditions under which function information attenuates name extension via shape.

Children often extend names to novel artifacts on the basis of overall shape rather than core properties (e.g., function). This bias is claimed to reflect the fact that nonrandom structure is a reliable cue to an object having a specific designed function. In this article, we show that information about an object's design (i.e., about its creator's intentions) is neither necessary nor sufficient for children to override the shape bias. Children extend names on the basis of any information specifying the artifact's function (e.g., information about design, current use, or possible use), especially when this information is made salient when candidate objects for extension are introduced. Possible mechanisms via which children come to rely less on easily observable cues (e.g., shape) and more on core properties (e.g., function) are discussed.

Child↗

PubMed2005

Representational and executive selection resources in 'theory of mind': evidence from compromised belief-desire reasoning in old age.

Effective belief-desire reasoning requires both specialized representational capacities-the capacity to represent the mental states as such-as well as executive selection processes for accurate performance on tasks requiring the prediction and explanation of the actions of social agents. Compromised belief-desire reasoning in a given population may reflect failures in either or both of these systems. We report evidence supporting this two-process model from belief-desire reasoning tasks conducted with younger and older adult populations. When task inferential complexity is held constant, neither group showed specific difficulty with reasoning about mental state content as compared with non-mental state content. However, manipulations that systematically increase executive performance demands within belief-desire reasoning caused systematic decreases in task performance in both older and younger adult groups. Moreover, the effect of increasing executive demands was disproportionately greater in the older group. Regression analysis indicated that measures of processing speed and inhibition contributed most to explaining variance in accuracy and response times in the belief-desire reasoning tasks. These results are consistent with the idea that compromised belief-desire reasoning in old age is likely the result of age-related decline in executive selection skills that supplement core mental state representational abilities, rather than as a result of failures in the representational system itself.

Adolescent↗

PubMed2005

Competence and performance in belief-desire reasoning across two cultures: the truth, the whole truth and nothing but the truth about false belief?

There is a change in false belief task performance across the 3-5 year age range, as confirmed in a recent meta-analysis [Wellman, H. M., Cross, D., & Watson, J. (2001). Meta-analysis of theory mind development: The truth about false-belief. Child Development, 72, 655-684]. This meta-analysis identified several performance factors influencing success, including manipulations that highlight the salience of the initial belief content (such as asking where Sally will look first for the marble). However, because a proportion of variance in performance remained unexplained even when identified performance factors were controlled for, the authors concluded from the standpoint of a 'theory-theory' account that children's improvement is the result of conceptual change. Further, the meta-analysis showed that manipulations such as 'look first' improve performance only in children who are in the older part of the 3-5 year range, and thus plausibly operating with a 'transitional' theory of mind--just on the point of realizing conceptual change. Here, we present three studies systematically investigating the 'look first' manipulation which showed that: (i) the advantage for the look first question can be demonstrated in children across different cultures, (ii) look first has an effect that is additive to the improvement with age; there is no interaction such that older children gain more benefit from younger children, (iii) performance in younger children can be, but is not always, elevated to levels that are statistically above chance. These results challenge the theory-theory account and are discussed in terms of models of belief-desire reasoning in which both conceptual competence and performance factors play central roles.

Attitude↗

PubMed2005

Belief-desire reasoning as a process of selection.

Human learning may depend upon domain specialized mechanisms. A plausible example is rapid, early learning about the thoughts and feelings of other people. A major achievement in this domain, at about age four in the typically developing child, is the ability to solve problems in which the child attributes false beliefs to other people and predicts their actions. The main focus of theorizing has been why 3-year-olds fail, and only recently have there been any models of how success is achieved in false-belief tasks. Leslie and Polizzi (Inhibitory processing in the false-belief task: Two conjectures. Developmental Science, 1, 247-254, 1998) proposed two competing models of success, which are the focus of the current paper. The models assume that belief-desire reasoning is a process which selects a content for an agent's belief and an action for the agent's desire. In false belief tasks, the theory of mind mechanism (ToMM) provides plausible candidate belief contents, among which will be a 'true-belief.' A second process reviews these candidates and by default will select the true-belief content for attribution. To succeed in a false-belief task, the default content must be inhibited so that attention shifts to another candidate belief. In traditional false-belief tasks, the protagonist's desire is to approach an object. Here we make use of tasks in which the protagonist has a desire to avoid an object, about which she has a false-belief. Children find such tasks much more difficult than traditional tasks. Our models explain the additional difficulty by assuming that predicting action from an avoidance desire also requires an inhibition. The two processing models differ in the way that belief and desire inhibitory processes combine to achieve successful action prediction. In six experiments we obtain evidence favoring one model, in which parallel inhibitory processes cancel out, over the other model, in which serial inhibitions force attention to a previously inhibited location. These results are discussed in terms of a set of simple proposals for the modus operandi of a domain specific learning mechanism. The learning mechanism is in part modular--the ToMM--and in part penetrable--the Selection Processor (SP). We show how ToMM-SP can account both for competence and for successful and unsuccessful performance on a wide range of belief-desire tasks across the preschool period. Together, ToMM and SP attend to and learn about mental states.

Choice Behavior↗

PubMed2005

Functional fixedness in a technologically sparse culture.

Problem solving can be inefficient when the solution requires subjects to generate an atypical function for an object and the object's typical function has been primed. Subjects become "fixed" on the design function of the object, and problem solving suffers relative to control conditions in which the object's function is not demonstrated. In the current study, such functional fixedness was demonstrated in a sample of adolescents (mean age of 16 years) among the Shuar of Ecuadorian Amazonia, whose technologically sparse culture provides limited access to large numbers of artifacts with highly specialized functions. This result suggests that design function may universally be the core property of artifact concepts in human semantic memory.

Adolescent↗

PubMed2004

Core mechanisms in "theory of mind".

Our ability to understand the thoughts and feelings of other people does not initially develop as a theory but as a mechanism. The "theory of mind" mechanism (ToMM) is part of the core architecture of the human brain, and is specialized for learning about mental states. Impaired development of this mechanism can have drastic effects on social learning, seen most strikingly in the autistic spectrum disorders. ToMM kick-starts belief-desire attribution but effective reasoning about belief contents depends on a process of selection by inhibition. This selection process (SP) develops slowly through the preschool period and well beyond. By modeling the ToMM-SP as mechanisms of selective attention, we have uncovered new empirical phenomena. We propose that early "theory of mind" is a modular-heuristic process of domain-specific learning.

Brain↗

PubMed2004

Neural correlates of detecting pretense: automatic engagement of the intentional stance under covert conditions.

Typically developing children begin to produce and understand pretend play between 18 and 24 months of age, and early pretense has been argued to be a candidate ''core'' capacity central to the deployment of representations of other peoples' mental states-''theory of mind.'' In a functional magnetic resonance imaging study, 16 healthy adult volunteers were imaged while watching short (5 sec) clips of actors who either performed simple everyday actions or pretended to perform a similar set of actions, under covert conditions (e. g., participants were not directed to attend to actors' mental states). There was increased activity in the medial prefrontal areas (Brodmann's areas [BA] 9/6/32, 9, and 10), inferior frontal gyrus bilaterally (BA 44, 47), temporo-parietal regions (BA 21 and 22), and parahippocampal areas, including the amygdala, when subjects viewed pretend actions as compared with real actions. This result suggests that at least some areas previously implicated in making explicit mental state judgments are also strongly activated in response to actions that call for mental state interpretation (e. g., pretense) even when there is no explicit instruction for ''mind reading.'' This outcome is discussed in terms of accounts that propose ''theory of mind'' to be underwritten by automatic specialized mechanisms for the interpretation of the behavior of social agents.

Adolescent↗

PubMed2003

Acquiring an understanding of design: evidence from children's insight problem solving.

The human ability to make tools and use them to solve problems may not be zoologically unique, but it is certainly extraordinary. Yet little is known about the conceptual machinery that makes humans so competent at making and using tools. Do adults and children have concepts specialized for understanding human-made artifacts? If so, are these concepts deployed in attempts to solve novel problems? Here we present new data, derived from problem-solving experiments, which support the following. (i) The structure of the child's concept of artifact function changes profoundly between ages 5 and 7. At age 5, the child's conceptual machinery defines the function of an artifact as any goal a user might have; by age 7, its function is defined by the artifact's typical or intended use. (ii) This conceptual shift has a striking effect on problem-solving performance, i.e. the child's concept of artifact function appears to be deployed in problem solving. (iii) This effect on problem solving is not caused by differences in the amount of knowledge that children have about the typical use of a particular tool; it is mediated by the structure of the child's artifact concept (which organizes and deploys the child's knowledge). In two studies, children between 5 and 7 years of age were matched for their knowledge of what a particular artifact "is for", and then given a problem that can only be solved if that tool is used for an atypical purpose. All children performed well in a baseline condition. But when they were primed by a demonstration of the artifact's typical function, 5-year-old children solved the problem much faster than 6-7-year-old children. Because all children knew what the tools were for, differences in knowledge alone cannot explain the results. We argue that the older children were slower to solve the problem when the typical function was primed because (i) their artifact concept plays a role in problem solving, and (ii) intended purpose is central to their concept of artifact function, but not to that of the younger children.

Awareness↗