Infants less than 8 months old appear to lack the concept of object permanence because they fail to search for hidden objects. However, when looking rather than reaching is assessed, infants appear to have object permanence long before 8 months. One explanation for the discrepancy is that young infants lack the means-end motor skill to retrieve objects hidden by covers. The present research tested the object permanence deficit hypothesis against the means-end deficit hypothesis. Direct-reach search tasks were used, which should result in increased search by young infants if the means-end deficit hypothesis is correct. In Experiment 1, 6- and 10-month-old infants were presented with an object visible in water, partly visible in milk hidden in milk, or hidden under a cloth. As predicted by the object permanence deficit hypothesis, 6-month-old infants were less likely to search when the object was hidden than when it was visible or partly visible, but there were no differences at 10 months. The means-end deficit hypothesis prediction that younger infants would be less likely to search when the object was hidden by a cloth than when it was hidden by milk was not confirmed. In Experiment 2, 6- and 10-month-old infants were presented with an object visible behind a transparent curtain, partly visible through a hole in an opaque curtain, partly visible (fit flashlight) under a cloth, and hidden behind a completely opaque curtain. As predicted by the object permanence deficit hypothesis, 6-month-old infants were less likely to search when the object was hidden than when it was visible or partly visible, but there were almost no differences at 10 months. Unexpectedly, measures of locomotor ability were not reliably related to infants' search at 6 months. In a comparison of the cloth event of Experiment 1 and the flashlight event of Experiment 2, half the results indicated that 6-month-old infants were more likely to search in the partly visible event. The results are more consistent with the object permanence deficit hypothesis than with the means-end deficit hypothesis.

This thesis explores the acquisition of dependent tenses. More specifically, it focuses on Sequence of Tense. This refers to the ability in some languages to report on an utterance with a direct speech in which a present tense is used (“I am happy”) with an indirect speech report in which a past tense is used (“John said he was happy”). Complementation plays crucial role in making the embedded tense depended on the matrix one. Therefore, the child first has to acquire complementation, i.e., the link between a main clause and a complement. If the child hasn't acquired complementation yet, he or she will not have independent tenses in this case. This thesis shows this hypothesis experimentally for three languages: English, Dutch and Japanese. The findings are that there is a stage, up to 4 years in which the child allows more readings, than adults. He or she can have “future” oriented readings, such as forward shifted readings as long as they occur before the utterance time of the sentence. They are explained by the child's lack of knowledge of complementation. Moreover, the linguistic phenomenon of Sequence of Tense is compared with a cognitive phenomenon, the development of a Theory of Mind. This phenomenon refers to the ability of expressing someone else's beliefs or thoughts without committing oneself to that belief or thought. A form of complementation is crucial in both phenomena. This thesis argues that complementation is acquired through the understanding of the difference in point of view between direct and indirect speech is what the child has to acquire. For instance, first person pronouns refer to the speaker of a sentence in indirect speech, but to the main clause subject in direct speech. Finally, this thesis extends the idea of the importance of point of view differences to the domain of wh-extraction in direct speech.

One of the most commonly reported findings in the epidemiology of psychological disorders is the 2:1 ratio of women to men who suffer from depression, a difference in prevalence rates that first emerges during the adolescent years. Although aspects of the feminine gender role have been identified as risk factors for depressive symptoms, the analysis of interpersonal interaction is rarely used to assess how these constructs may be behaviorally enacted. In this dissertation, interactions between mothers and adolescents were analyzed to identify specific sequences of behavior associated with adolescents' depressive symptoms, with the aim of clarifying reasons for the dramatic increase in depression among adolescent girls. A community sample of 79 adolescents & their families participated over a 3-year period. Thirty-two consecutive segments of a videotaped problem-solving interaction task were viewed by participants and coded on the dimensions of support, conflict, giving-in, humor, misunderstanding , and sarcasm. Using sequential analyses and multiple linear regression, I assessed the extent to which sequences consistent with the feminine gender role (conflict paired with giving-in ) predicted concurrent and future depressive symptoms. Additional exploratory analyses examined maternal reactions to adolescent conflict. Results indicate that the pairing of conflict with giving-in during problem-solving interactions is predictive of future depressive symptoms, and that adolescent sex and history of depressive symptoms moderate this relation. As expected, the behavioral combination of conflict with giving-in was a riskier one for girls and for adolescents with a history of depressive symptoms. Maternal responses to adolescent conflict did not differ when mother-son dyads were compared to mother-daughter dyads.

Autosomal recessive primary microcephaly (MCPH, MIM 251200) is a neurodevelopmental disorder that results from a loss of neural progenitors in the embryonic neocortex. Patients with MCPH have a significantly small brain and exhibit reduced cognition. MCPH is a genetically heterogeneous disease involving mutations in thirteen genes, nine of which centrosome protein-coding genes, one of which is CDK5RAP2. The centrosome is the major microtubule organizing center in all animal cells. While MCPH is a neural stem cell disease, the molecular mechanisms for the disease remains unknown. Proteomic analysis of a mutant in the Drosophila CDK5RAP2 ortholog, centrosomin (cnn), we discovered proteins involved in intermediary metabolism, oxidative stress, and inherited Parkinson's disease that were post-translationally modified in mutant brains relative to wild type brains. These findings led us to discover that cnn mutants have neurological defects, including poor locomotor and flight performance, and are less active. We further demonstrated that cnn and Sas-4 (MCPH6/CPAP in human) mutant cells have elevated reactive oxygen species (ROS) levels, chronically activating the Jun N-terminal kinase (JNK) stress signaling pathway and thus activating FOXO by nuclear localization. The cause for these stress responses appears to be due to a severe deficiency in autophagy induction in MCPH mutant cells. Autophagy is a major catabolic pathway for the degradation of damaged proteins and organelles. Here we show that MCPH proteins are required for autophagy induction and act downstream of mechanistic target of rapamycin (mTOR) kinase, a negative regulator of autophagy. Together these results demonstrate a novel function for MCPH genes in oxidative stress and regulating autophagy. / A Dissertation submitted to the Department of Biomedical Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2014. / November 7, 2014. / autophagy, centrosome, microcephaly, oxidative stress / Includes bibliographical references. / Timothy Megraw, Professor Directing Dissertation; Yoichi Kato, Committee Member; Branko Stefanovic, Committee Member; Yanchang Wang, Committee Member.

In a sample of non-patient late adolescent women (N=110), this study investigated associations between pubertal timing, interpersonal conflict, and HPA-Axis dysregulation. Primary focus was on the interactional nature of pubertal timing as a risk factor, and the potential mediating role of specific coping behaviors. At high levels of perceived conflict, earlier pubertal timing was associated with both high stress in anticipation of interpersonal negotiation and low physiological recovery following the interaction. At low levels of perceived conflict, later pubertal timing was associated with both high stress in anticipation of interpersonal interaction and low physiological recovery following the interaction. Results suggest further investigation of behaviors which mediate between pubertal timing and girls' physiological response to stress.

Kindergarten, first grade, and second grade students' knowledge of fractions and whole numbers was tested using a number line consisting of whole circles. After a brief training session, students placed displays consisting of circles and pieces of circles on a number line. Kindergarten students did not complete the task correctly. First and second grade students performed better than kindergarten students; however, their performance was related to the training procedure they received. Training with a number line consisting of fractional quantities increased first and second grade students' performance. The findings fail to support the belief that elementary students treat fractions as whole numbers. Instead, the findings provide tentative evidence that task related issues, such as the type of number line used during training, may underlie students' performance on similar number line tasks.

Throughout development, infants are continually adding new skills to their behavioral, cognitive and perceptual repertoire. During the period in which these skills are new, they require some degree of controlled processing, and present the potential to reduce resources available for other cognitive or motor activities. The current study examined the function of attention in managing concurrent demands of cognitive and perceptual-motor processes in 24 month-old children. A primary cognitive task (nonspatial working memory search) was combined with one of three secondary action tasks (requiring high, reduced, or minimal levels of controlled processing), in order to tax attentional resources to the point that performance on the primary search task would suffer. Significant disruptions in search performance were observed with the introduction of a secondary task, but the expected differential interference effects based on level of controlled processing were largely absent. Those conditions which required controlled processing showed no added interference compared to conditions with lessened or no controlled processing requirements. The primary costs to search performance seem to be incurred as children encounter a new task and shift their focus away from the initial task. If children experience any differential effects due to cognition-action resource conflicts, they appear to be masked by the significant effects of disengaging and reengaging with the primary search task.

This short-term longitudinal study investigated changes in newborn infant behavior over the first month of life and changes in mothers' mental representations of their infants and of themselves as parents, during the first month postpartum. There is evidence to suggest that maternal representations and newborn infants' behavior play an important role in the evolving infant-mother relationship, and that a newborn infants' developmental progress is dependent upon the quality of that relationship. While there is some research on neonatal behavioral development in Puerto Rican infants, there are no data on the development of maternal representations in Puerto Rican mothers. The study's sample consisted of 20 newborn infants and their mothers. Infants were examined on the Clinical Neonatal Behavioral Assessment Scale (CLNBAS)(Nugent, 2001), during the first 48 hours of life and at one month postpartum. Mothers' representations were examined using the Maternal Representation Questionnaire (MRQ)(Stern & Stern-Brushwieler, 1999). This is the first study to use the CLNBAS and the MRQ for data collection during the first month. Results showed that newborn infant behavioral patterns of Puerto Rican infants changed in a positive direction during the first month postpartum. More specifically, significant positive developmental changes in the areas of autonomic, motor, and social interactions were found, while there were no changes in state organization, as measured by the CLNBAS. Results also revealed that mental representations of Puerto Rican mothers were positive and stable during the first month postpartum. Puerto Rican mothers' mental representations during the first month barely changed, were very positive, and also consistent with the positive newborn developmental changes as assessed by the CLNBAS during the first month of their infant's life. Mothers' knowledge of their infants' capacities increased over the course of the first month and they felt they became more effective and comfortable in their role as new mothers. Mothers also reported feeling well supported by family and friends during their transition to motherhood. In summary, this study contributes to the understanding of newborn behavioral changes and maternal representations early in the development of the mother-infant relationship in the context of Puerto Rican families.

Inference is a process by which appropriate belief states get connected. Belief states are biological states in the sense that they are reentrant loops (or loops which connect different stimulus); their intrinsic feature is recognition. In inference or reasoning the transition process between belief states is regulated by the rule of concept usage, involved in the belief state, in natural language. Like belief states experiential states are also biological states whose extrinsic feature is recognition, such that, one can have an, say, X-type experience without recognizing it as an experience of X. One can, however, also have an experience of an X; in the latter case, one not only has an X-type experience but also recognizes an X as an X. In some cases the transition from X-type experience to believing an X to be there instantiates a quasi-inferential pattern. In all such cases the transition process is regulated by the rule of X usage. In such quasi-inferential transition additional belief states are involved. Such states assert that there are no countervailing factors and there are additional factors conducive to the conclusion. Such belief states are expressed non-propositionally in the language of thought. Propositions are a necessary part of such quasi-inference for they give content to thoughts to which one can assign 'falsity' and defeasible reasoning requires us to assign 'falsity' to our thoughts. Propositions implicated in the quasi-inferences from experience types to belief states are the evidential reasons for the conclusion and they can only be accepted as provisionally true and have to be revised in the light of further information.

Building upon previous emergent literacy research, this descriptive and correlational longitudinal study investigated the relationship between parent-child storybook reading and children's early literacy skill development. A new, reliable videotaping system was used as was a measurement tool sensitive to the growth of children's early literacy skills, the Dynamic Indicators of Basic Literacy Skills (DIBELS). Twenty-five parent-child dyads volunteered for phase one; all children were 3 to 5 years old. Eighteen of the original 25 children participated in a follow-up study a year later. Most families were Caucasian, English-speaking, and interested in literacy activities. Dyads were videotaped reading storybooks and their interactions were coded. Six video categories became predictor variables: Parent Q, A, D, L (Parent questions, answers, discusses content of book, or discusses book as it relates to life of parent or child); Child Q, A, D, L; Child reads or is prompted to read, Off-task events, Total events; and Words read per minute. Other predictor variables included Minutes per week of Parent and Parent-child reading (derived from a parent interview) and children's scores from the Early Screening Profiles (ESP) Cognitive/Language Profile subtest of the American Guidance Service (AGS). These variables were correlated with dependent variables obtained by administering three DIBELS tests to the children: Onset Recognition Fluency (ORF) and Letter Naming Fluency (LNF), used in both phases, and Phoneme Segmentation Fluency (PSF), used only in follow-up. Only children 5 and older were administered the age-sensitive PSF probes. From follow-up scores, slope data were generated measuring progress in the three skill areas. A number of the video predictor variables correlated at .32 (a small effect size) or above with the children's concurrent LNF scores. The children's ESP cognitive and language scores also correlated at .32 or above with several of the children's concurrent or subsequent DIBELS scores. Description and discussion of the direct observation system and parent interview are included, with suggestions for refinements. The ESP and DIBELS are discussed, and recommendations are made for future research.