Matrix training techniques arrange instruction for stimulus relations that facilitate emergent responding to novel stimulus arrangements, which is a phenomenon known as recombinative generalization. The current study compared two common matrix training approaches, an overlapping (OV) design and a non-overlapping (NOV) design, with respect to arranging relations targeted for training. Two, typically-developing toddlers were taught compound action-object labels in either an OV or NOV matrix training design. Results suggest that an OV matrix design facilitates recombinative generalization more effectively than a NOV design.

Children playing on playgrounds is a common sight, one most people have witnessed and participated in. While playground spaces are scattered throughout the United States as places for children to explore, they often reflect adult notions of childhood and come in standardized forms, which often neglect the interests of children. Situated at the nexus of critical childhoods and spatial theories, this study argues that children’s playground spaces are valuable sites of study, as are the experiences of children utilizing them. While easy to ignore the desires of very young children, or brush them off as unimportant or uninformed, this study emphasizes the value of seeing, hearing, and prioritizing the experiences of two-year old’s as they navigate playground spaces. Utilizing researcher and child-driven methods, children’s verbal and nonverbal modes of communication were valued and reflected in the findings. Children’s movements through playground spaces were reflective of their sensory and embodied ways of being, as well as their connection with the material world. This work proposes that more attention be paid to children’s actual lived experiences in playground spaces and that this be considered when designing and constructing these spaces.

Autism spectrum disorders (ASDs) are a group of disorders that affect social, communication, and behavioral development. Identification of clinically distinct subtypes of ASDs, especially in the developmental period when delays or deficits are first recognized (i.e., in the first few years of life), can lend clues to etiology and trajectory and enhance current knowledge on early manifestations of the disorders. Moreover, identification of clinically distinct subtypes of ASDs may inform early identification efforts. Past research suggests that social relations, verbal abilities, nonverbal abilities, and the presence of certain stereotyped interests and behaviors (SIB) may be important factors in delineating subtypes of ASDs in toddlers. Yet there is no published study that examines empirically derived subtypes in a sample of such young children. Therefore, the purpose of this study was to determine whether clinically distinct subtypes can be derived from a sample of toddlers who fail an autism screen and are subsequently diagnosed with developmental concerns, including an ASD. Results found that subtypes delineated by social-communicative maturity were found in both of the aforementioned samples of children. Furthermore, the ASD only sample was also distinguished by rate and intensity of certain types of SIB. Implications for autism theory, early identification, and early intervention are discussed.

There is increasing evidence that biological factors (i.e., hormones) support the development of sex differences in behavior by organizing brain systems in prenatal life. However, the behavioral significance of the surge in reproductive steroids that results from the transient activation of the hypothalamic-pituitary-gonadal (HPG) axis around 3-months of age is largely unknown. The goal of the present study was to investigate the role of early postnatal activation of the HPG axis in the development of sex differences in human behavior. Participants included 54 children between 18 and 24 months (32 males and 22 females) and their parents. Infants and their caregivers participated in two, eight minute play sessions that were video-taped and later coded for children’s aggressive behavior and vocal ability. During each session, children wore an actigraph (Actiwatch, Philips Respironics) to provide a nonbiased assessment of activity levels. In addition, toddler’s temperament was measured using the Brief Infant Toddler Social-Emotional Assessment (BITSEA). Saliva samples from each infant were collected at 3-4 months of age and levels of testosterone were measured. Digit ratio levels were also measured at 3-4 months and used as a marker of prenatal androgen levels. The data indicated that boys were more aggressive, engaged in higher levels or activity, and showed less developed language ability. In addition, our results demonstrated that hormone markers associated with higher (i.e., more male-typical) testosterone were related to more aggressive behaviors, higher activity levels, expression of fewer total words, and a shorter duration of time spent vocalizing. A novel finding was that higher testosterone (i.e., more male-typical) levels in early postnatal life predicted less time spent vocalizing, for both sexes together and within males. The present research suggests that hormone levels in early postnatal life may contribute to the development of gender phenotypes, potentially making this a critical period for the development of language and other gender-linked behaviors.

Thesis (Ph. D.)--University of California, San Diego, 2008. / Title from first page of PDF file (viewed February 14, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Thesis (Ph. D.)--West Virginia University, 1998. / Title from document title page. Document formatted into pages; contains x, 93 p. Vita. Includes abstract. Includes bibliographical references (p. 62-72).

Thesis (M.A.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 79-86). Also available on the Internet.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vi, 67 p. : map. Includes abstract. Includes bibliographical references (p. 44-45).

Thesis (M.A.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 79-86). Also available on the Internet.

Thesis (B.Sc)--University of Hong Kong, 1999. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 14, 1999." Also available in print.