Susan Johnson - US grants

DESCRIPTION: Current estimates reveal that 25 percent of American children are obese and that the incidence of early childhood obesity is increasing. Many overweight children become obese adults who constantly struggle with weight issues and the metabolic disorders that accompany obesity. If a child enters adolescence in the obese state, the odds are 4 to 1 against achieving normal weight later in life. Thus, it is evident that prevention or early management of this disease is critical in combating a lifetime of obesity and its complications. However, when long-term success rates of the numerous treatment programs are examined it becomes apparent that the adult who maintains a long-term weight loss is an anomaly. The results for children are even more grim since there is little research, and less consensus, regarding the treatment of childhood obesity. Previously reported studies have focussed on selectively modifying behaviors which precede obesity onset (food intake and exercise protocols) or alternatively on documenting and ameliorating the metabolic consequences of obesity. The aim of this proposal is to unify behavioral and metabolic procedures under a common experimental design to produce a comprehensive view of the antecedents and consequences of early childhood obesity. Previously developed protocols will be employed to characterize individual children, 5-10 years of age, with respect to: 1) their ability to regulate food intake; 2) the influence of diet composition on children's food intake regulation; 3) their body composition characteristics; 4) 24 hour energy expenditure as determined by whole room indirect calorimetry; and 5) selected psychological variables such as children's self-esteem, body image and their perception of the degree to which parents attempt to control their eating behavior. In addition, data will be collected which focusses on the family environment so that differences in children's outcome measures can be interpreted in the context of the family environment in which they have developed. Parents' dieting histories and weight statuses, their concerns about their children's weight statuses as well as their child-feeding practices will be measured. These data will be used to test a model of obesity development which, based upon preliminary data, suggests that children's energy intake regulation and weight outcome are the result of a bidirectional relationship between parents and children that is both genetic and environmental in nature. The long-term goal of this line of research is to identify points at which effective intervention and prevention strategies can be developed.

Recent work on the development of conceptual knowledge and intuitive theories in normally developing children has identified certain points in the natural learning path which, although necessary for development to occur, nonetheless impose relative conceptual bottle necks on the learning process. These conceptual bottlenecks occur when a theory that the child is trying to acquire (e.g. the adult's biological theory) does not map directly into concepts in the child's existing theory. Learning that involves mismaps of this sort requires deep conceptual change on the part of the child; conceptual change that is low, slow, and mentally difficult to achieve compared to learning which does not involve these mismaps. Williams syndrome is a neurodevelopmental disorder of genetic origin that leads to mental retardation. One result of this retardation seem to include the inability to spontaneously negotiate these conceptual bottle- necks the way that normally developing children do, at least in the domain of intuitive biology. The aim of this project is to gather more information on the scope and impairment in WS. Adults and adolescents with WS will be tested for their conceptual achievements in the domain of number, specifically with regard to number of concepts implicated in conceptual change, i.e., cardinality, zero, infinity, and conservation. Their performance will then be compared with that of normally developing children matched for verbal mental age. A better characterization of the underlying impairment in WS will pave the way for a clearer understanding of the cognitive mechanisms involved in conceptual change and the possible avenues for intervention and remediation and impaired populations.

The ability to attribute mental states such as perception, attention, desire, or belief to ourselves and others is critical to humans' social and cognitive competence. With this ability we can communicate referentially, predict and explain each others' behaviors, and manipulate both our own and others' mental states for the purposes of complex problem-solving and learning, not to mention deception. When and how this ability becomes available to children is therefore of particular theoretical importance. The current aim is to examine several unresolved questions in this regard. When can we justifiably claim that infants attribute mental states to others? When they do, who do they attribute mental states to and on the basis of what evidence? The answer to these questions will in turn provide insight into the representational systems underlying mentalistic reasoning. The research proposed will begin with the findings of Johnson, Slaughter, and Carey (1998) in which infants were found to follow the "gaze" of novel objects that embodied characteristics of mentalistic beings, in particular the ability to interact contingently with other agents. This result has been interpreted as a reflection of the infant's attribution of attention and/or perception to the object, i.e., infants follow the object's "gaze" in order to find what it is "looking at." Two complementary series of studies are proposed to examine this interpretation. The first series will attempt to more fully characterize the parameters and representation of contingent interaction as it functions in eliciting gaze-following both in infants and adults. The second series of studies will examine the meaning that infants assign to objects identified via contingency information by examining its effectiveness in eliciting putatively mentalistic attributions across a wide variety of behavioral contexts including imitation, the elicitation of communicative gestures, and the violation of expectations based on mentalistic interpretations.

DESCRIPTION (provided by applicant): Nearly half a century ago, psychiatrist John Bowlby proposed that the instinctual behavioral system that underpins an infant's attachment to its mother is accompanied by "internal working models" of the social world - models based on the infant's own experience with her caregiver. These mental models were thought to mediate, in part, the ability of an infant to use her caregiver as a buffer against the stresses of life, as well as the later development of important self-regulatory and social skills. Hundreds of studies now testify to the impact of caregiver behavior on infant behavior and development: Infants who most easily seek and accept support from their parent are considered secure in their attachments and are more likely to have received sensitive and responsive caregiving than insecure infants. Insecurely attached infants are at higher risk for the later development of both externalizing behavior problems such as conduct disorders and internalizing behavior problems such as depression and anxiety. The mental models of older children have been shown to predict many of the same developmental sequelae as do the more behavioral measures. Yet no study has ever directly assessed internal working models in infancy. The specific aim of the present proposal is to use established visual habituation methods to examine the impact of infants'experiences with their caregivers on their ability to represent and process abstract social relations. Two exploratory studies will be conducted with 12-month-olds. The first study will examine infants'expectations of caregiver responses to bids for attention. The second study will explore infants'expectations of infant responses to caregiver return. Performance on both studies will be compared to infants'attachment status as measured in the Strange Situation. The long-term goals are to examine (1) the interrelationships between these early cognitive representations and other emerging abilities in infancy, for instance how individual differences in goal- attribution or emotion recognition might interact with infants'interpretation of caregiver behavior, and (2) the relationship between early mental representations and long-term developmental adjustment, thereby suggesting new avenues for prevention and treatment of attachment-related maladjustment. Infants with poor attachments to their caregivers are at risk of later mental health problems such as anxiety, depression, oppositional defiant disorder or conduct disorder. This research uses established methods from the field of infant cognition to examine whether infants'understanding of social interactions is influenced by their experiences with their own caregivers. Such a finding would open new avenues for the prevention and treatment of attachment-related maladjustment in childhood.