Presentation on theme: "Conceptual Development in Williams syndrome: living things and artifacts Ágnes Lukács HAS - Budapest University of Technology and Economics Research Group."— Presentation transcript:
Conceptual Development in Williams syndrome: living things and artifacts Ágnes Lukács HAS - Budapest University of Technology and Economics Research Group on Neuropsychology and Psycholinguistics Research Institute of Linguistics, Hungarian Academy of Sciences, Budapest, Hungary
Conceptual knowledge in WS Relatively good and sophisticated form in language often reflects superficial knowledge Semantic impairments and deficits in conceptual knowledge are main areas of difficulty Very few studies addressed the question of conceptual development in WS, and the nature of the impairment is yet unknown.
Conceptual knowledge in WS Johnson and Carey (1998) tested knowledge of biological concepts and hypothesized that superficiality is the result of failure to develop T2 concepts, which require conceptual change besides conceptual enrichment. Studies are presented testing the domain of folkbiology and intuitive knowledge of artifact concepts. We compared results of the WS group to a group of typically developing children matched on vocabulary scores.
Conceptual change Development is a series of radical conceptual shifts or restructurings in which the most current understanding is inexplicable within (incommensurate with) prior conceptual structure (Carey) Alternatively, development is discussed as more gradual enrichment of multiple existing early explanatory systems, allowing for commensuarability over time and change (Keil) debate with specific focus on naive biological understanding
Living things: Naïve biology Carey (1985, 1988) The autonomous domain of biology is not constructed until the end of the first decade of life ( life, death, man-as-one-of-the-animals, species-as-determined- by-the-origin-of-the-animal) Autonomous domain: a set of phenomena of biology involving a domain of ontologically distinct entities, and unique causal mechanisms which provide explanation for the phenomena in the domain and the properties of the entities In preschoolers all biological phenomena are initially interpreted in psychological and behavioral terms. Only later does distinctly biological thought emerge from psychological concepts Animistic biology conceptual change to a different theory Vitalistic biology within-theory restructuring and enrichment Mechanistic biology
Artifacts: The design stance Adults reason about artifacts in terms of the design stance: reasoning about the intended function is the most heavily weighted feature because people try to rationalize all they know about an artifact, and the intended function constrains this process. When in does the design stance become available to organize children's understanding of artifacts and to provide the core of the meaning of artifact terms? –Early:late infancy, as is the physical stance and the intentional stance –only later as some framework theories such as vitalist biology (constructed around age 5 or 6)
Johnson and Carey (1998) Knowledge Enrichment and Conceptual Change in Folkbiology: Evidence from Williams Syndrome. Cognitive Psychology, 37, 156–200 Explanation of semantic anomalies in WS Study of knowledge and interpretation of biological concepts like animal and death 10 participants with WS (10;7-32;1, mean age: 24;3), two control groups with mean ages 10;11 and 6;7 Two batteries equated on difficulty and cognitive load : –T1/T2 neutral animal knowledge: preschoolers general conceptual knowledge –T2: folkbiological concepts developing between 6 and 12 years of age, for the construction of which a conceptual change is needed
Johnson and Carey (1998) They argue that knowledge enrichment (i.e. adding information to already existing conceptual structure) is relatively functional, while conceptual change (reorganizing knowledge) is difficult; this results in deviant and less sophisticated semantic representations in WS
Our studies Methods were taken from the current literature on conceptual development on biological and artifact concepts Subjects were always selected from a pool of –14 participants with WS (mean age: 16,23, SD: 4,23; mean Peabody score: 103,41, SD: 30,84)) –matched individually on Peabody scores to a group of 14 TD children (mean age: 7,6, SD: 1,13; mean Peabody score: 103,91; SD: 30,87)
Species transformations (Keil, 1989) Two stories of costumes transformations (goat-sheep, zebra-horse) and two stories of surgery transformations (tiger-lion, raccoon-skunk) accompanied by pictures Participant first shown the picture of the original animal, then the story of the transformation is told. The picture of what the animal looked like afterwards is shown, and the participant is asked e.g. Now that the doctor is done (showing the picture of the transformed animal) what kind of animal is it? Is it a lion or a tiger? Then the participant`s answer is challenged: Even though it looks like a lion, you think it is a what? Or Even though it was a tiger to start with, and its parents were tigers too, you think it is what?
Species transformation Young preschoolers accept that costume change can change species kind, but by age 5, they do not Johnson and Carey (1998): –few of their participants (WS and control) accepted firmly that costume change changes species kind. WS were unsure, controls rejected –The surgery task requires T2 knowledge. Most control participants denied that surgery could change species kind, while most WS participants accepted
Species transformations WSVC External change* 179 Internal change14 *: p<0,05; no performance differed significantly from chance, Max=28 for each cells, with 14 participants in each group and two questions in each type
Conclusions J&C: WS were unsure about, controls rejected costume change, in our study participants with WS were more likely to accept it as a basis of species transformations than controls J&C: WS group, just as younger controls accepted surgery more than controls, we did not find a difference, but both groups were at chance J&C WS group 8 years older on average Our study confirmed J&C`s finding, that WS participants do not understand the concept species-as-determined- by-the-origin-of-the-animal
Solomon et al. (1996): Like Father, Like Son: Young Children`s Understanding of Why Offsprings Resemble their Parents. Child Development, 67, Carey (1985,1988): Children understand biological inheritance only to the extent that they understand that for certain characteristics the chain of processes underlying Resemblance to Parents crucially involves birth 4-7 year olds: a story in which a girl born to a woman and adopted by another. The biological mother had one set of features (e.g. green eyes), the adoptive mother had another (e.g. brown eyes) It was not until age 7 that children associated the girl with her biological mother on physical features and to his adoptive mother on beliefs, understanding birth as part of a process selectively mediating the acquisition of physical traits and learning or nurturance as selectively mediating the acquisition of beliefs
Solomon et al. (1996) Physical traits: green eyes, liver on the left side,black skin, small posture Beliefs: you have to stop at the red light, squirrels see in the dark, ghosts exist, chocolate is not healthy Two conditions: Parent resemblance Changes with development
Results Inheritance (resembles biological mother) N=8WSVC Physical3,37 Belief1,871,5 Change with development (does not change) N=7WSVC Physical3,132 Belief1,62 Cells show mean number of responses, max=4.
Results Inheritance –No GROUP effect –Significant effect of Property type –No significant interactions Change with development –No significant effects
Conclusions Both groups seem to understand that physical traits are inherited from the biological parent, and beliefs are more likely to be influenced by adoptive parent Understanding of how different features and beliefs can change is much less sophisticated Maybe understanding of biological inheritance is not due to a coherent theory of biology, and causal status of birth in it, but a richer knowledge of inheritable properties in both WS and in TD at this age
Matan and Carey (2001) Developmental change within the core of artifact concepts. Cognition 78 (2001) 1-26 Examining the relative importance of original function and current function in artifact categorization: when does the design stance become available for children Participants were asked to judge whether an artifact that was made for one purpose (e.g. making tea) and was currently used for another purpose (e.g. watering flowers) was a teapot or a watering can. Adults rely on original function, 6 year olds pattern with adults, 4 year olds do not Only 6 year olds begin to use the design stance in their interpretation of artifacts
Keil et al. (1998) Two dogmas of conceptual empiricism: implications for hybrid models of the structure of knowledge. Cognition, 65, 103–135 Children do learn as they get older, but the sorts of things they are capable of learning may not undergo qualitative changes such as a shift from from similarity to causal frameworks or rules. Explanatory knowledge already constrains initial tabulations of similarity, consisting of e.g. causal centrality and typicality of properties with respect to a concept By describing a novel category and and posing strucuturally relatively simple questions Keil et al. explored intuitions about causal centrality from 5 years of age
Animals and machines They read stories about a novel animal and a novel machine, describing 6 property types (plus two controls). Then they asked children if other instances of the described category had to share the same property as those described in the story, or whether something could still belong to a category if it differed on a particular property type. Machine and animal stories described the same property types.
Keil et al. (1998) Animal questions Dou you think that Gilbis really have to have dirt on their tails, or could something still be a Gilbi even if it didn`t have dirt on its tail? [control] Dou you think that Gilbis have to be the same size as the one I saw? Dou you think that Gilbis have to be brown? Dou you think that Gilbis really have to have black stripes on their backs? Dou you think that Gilbis have to be the same weight? Dou you think that Gilbis really have to have the same number of inside parts? Dou you think that Gilbis really have to have the same kinds of parts on the outside? Could something be made of butter and still be a Gilbi? [control]
Keil et al. (1998) Kind (animal vs machine) had a significant effect in all groups, except with 5 year olds, where it only approached significance Age did not have a significant main effect (5, 7 and 9 year olds), no systematic developmental changes were found The effect of Property was significant All six properties diffenetiated animals and machines in all age groups Shape of outside, number of inside parts, colour and surface markings mattered more for animals than for machines Size and weight mattered more for machines than animals
Number of children who judged that a property was irrelevant to category membership N=13 in each groupAnimalsMachines *: differs from chanceWSVCWSVC Size911* 10* Colour9811*10* Surface marking8711*9 Weight11* 10*7 # of inside parts6686 Shape of outside parts7855 Coding: the belief that the animal or object with the changed property could still be a member of the category was coded as 1 No group differences were significant
Conclusions No effects found by Keil et al. (1998) were replicated The tendencies we observe often point to the opposite direction (e.g. colour and surface markings matter more for machines) Methodological concerns: very small sample size, did not understand the task [but control questions were OK] Or: Explanatory knowledge does not constrain similarity tabulations neither in WS, nor in typical development at this age (mean age for control group was 7;6). Neither group recognized the differential importance of specific property types for animals and machines.
General Conclusions Participants with WS do not understand concepts that require theory change in Careys view –they do not understand species-as-determined-by-the-origin-of-the- animal –they do not take the design stance in their artifact concepts Inability to apply more sophisticated explanatory systems does not necessarily imply a deficit in conceptual reorganization: a general deficit of perceiving and applying causal relations can be an explanation (cf. the animals and machines task) This deficit is most probably not specific to WS, but a general characteristic a mental retardation