Prenatal augmented auditory stimulation and visual system development: Effects of timing on intersensory organization

This study investigated the effects of augmented prenatal auditory stimulation on postnatal visual responsivity and neural organization in bobwhite quail (Colinus virginianus). I delivered conspecific embryonic vocalizations before, during, or after the development of a multisensory, midbrain audiovisual area, the optic tectum. Postnatal simultaneous choice tests revealed that hatchlings receiving augmented auditory stimulation during optic tectum development as embryos failed to show species-typical visual preferences for a conspecific maternal hen 72 hours after hatching. Auditory simultaneous choice tests showed no hatchlings had deficits in auditory function in any of the groups, indicating deficits were specific to visual function. ZENK protein expression confirmed differences in the amount of neural plasticity in multiple neuroanatomical regions of birds receiving stimulation during optic tecturn development, compared to unmanipulated birds. The results of these experiments support the notion that the timing of augmented prenatal auditory stimulation relative to optic tectum development can impact postnatal perceptual organization in an enduring way.^

Contingency, contiguity, and development: The ontogeny of contingency learning in northern bobwhite (Colinus virginianus) chicks

The purpose of this study was to investigate the ontogeny of auditory learning via operant contingency in Northern bobwhite (Colinus virginianus ) hatchlings and possible interaction between attention, orienting and learning during early development. Chicks received individual 5 min training sessions in which they received a playback of a bobwhite maternal call at a single delay following each vocalization they emitted. Playback was either from a single randomly chosen speaker or switched back and forth semi-randomly between two speakers during training. Chicks were tested 24 hrs later in a simultaneous choice test between the familiar and an unfamiliar maternal call. It was found that day-old chicks showed a significant time-specific decrement in auditory learning when trained with delays in the range of 470–910 ms between their vocalizations and call playback only when training involved two speakers. Two-day-old birds showed an even more sustained disruption of learning than day-old chicks, whereas three-day-old chicks showed a pattern of intermittent interference with their learning when trained at such delays. A similar but less severe decrement in auditory learning was found when chicks were provided with motor training in which playback was contingent upon chicks entering and exiting one of two colored squares placed on the floor of the arena. Chicks provided with playback of the call at randomly chosen delays each time they vocalized exhibited large fluctuations in their responsivity to the auditory stimulus as a function of delay—fluctuations which were correlated significantly with measures of chick learning, particularly at two-days-of-age. When playback was limited to a single location chicks no longer showed a time-specific disruption of their learning of the auditory stimulus. Sequential analyses revealed several patterns suggesting that an attentional process similar or analogous to attentional blink may have contributed both to the observed fluctuations in chick responsivity to the auditory stimulus as a function of delay and to the time-specific learning deficit shown by chicks provided with two-speaker training. The study highlights that learning can be substantially modulated by processes of orienting and attention and has a number of important implications for research within cognitive neuroscience, animal behavior and learning.

Predictors of developmental gains in children enrolled in an early intervention setting

The purpose of this research was to determine whether initial developmental delay, site of intervention, frequency of intervention, age of the child, socio-economic status (SES), gender and ethnicity significantly predict developmental gains in a group of children enrolled in an early intervention setting. The records of 134 children enrolled in an inner-city program in Miami, Florida were reviewed for inclusion in this study. ^ Demographic variables, site placement and treatment frequencies were collected during a retrospective chart review. Level of delay was expressed using the developmental quotient and developmental gain was calculated using the mean gain on age equivalent scores or developmental tests. A multiple regression analysis was performed to determine which of the above variables significantly predicted developmental gains. Multivariate analysis compared developmental gains for all the developmental domains based on intervention site (center versus home-based) while controlling for developmental delay. ^ Children made greater developmental gains if they had higher developmental quotients and if they were younger at the time services were initiated. Frequency of intervention significantly improved developmental outcomes in children attending center-based programs. Children attending center-based programs also made significantly greater gains in gross motor skills compared to children attending home-based programs. ^ These findings emphasize the importance of early screening and referral of children with developmental delay and adjusting intervention for the child's developmental quotient. Children should receive intense treatment to maximize results. Decisions regarding program placement should be individualized according to the child's unique developmental pattern. Policy and program decisions affecting the curriculum of a child in early intervention need to reflect these multivariate considerations. ^

The role of temporal synchrony in the facilitation of perceptual learning during prenatal development

This study explored the critical features of temporal synchrony for the facilitation of prenatal perceptual learning with respect to unimodal stimulation using an animal model, the bobwhite quail. The following related hypotheses were examined: (1) the availability of temporal synchrony is a critical feature to facilitate prenatal perceptual learning, (2) a single temporally synchronous note is sufficient to facilitate prenatal perceptual learning, with respect to unimodal stimulation, and (3) in situations where embryos are exposed to a single temporally synchronous note, facilitated perceptual learning, with respect to unimodal stimulation, will be optimal when the temporally synchronous note occurs at the onset of the stimulation bout. To assess these hypotheses, two experiments were conducted in which quail embryos were exposed to various audio-visual configurations of a bobwhite maternal call and tested at 24 hr after hatching for evidence of facilitated prenatal perceptual learning with respect to unimodal stimulation. Experiment 1 explored if intermodal equivalence was sufficient to facilitate prenatal perceptual learning with respect to unimodal stimulation. A Bimodal Sequential Temporal Equivalence (BSTE) condition was created that provided embryos with sequential auditory and visual stimulation in which the same amodal properties (rate, duration, rhythm) were made available across modalities. Experiment 2 assessed: (a) whether a limited number of temporally synchronous notes are sufficient for facilitated prenatal perceptual learning with respect to unimodal stimulation, and (b) whether there is a relationship between timing of occurrence of a temporally synchronous note and the facilitation of prenatal perceptual learning. Results revealed that prenatal exposure to BSTE was not sufficient to facilitate perceptual learning. In contrast, a maternal call that contained a single temporally synchronous note was sufficient to facilitate embryos’ prenatal perceptual learning with respect to unimodal stimulation. Furthermore, the most salient prenatal condition was that which contained the synchronous note at the onset of the call burst. Embryos’ prenatal perceptual learning of the call was four times faster in this condition than when exposed to a unimodal call. Taken together, bobwhite quail embryos’ remarkable sensitivity to temporal synchrony suggests that this amodal property plays a key role in attention and learning during prenatal development.

Estrogen and lithium: Facilitating factors involved in brain cell signaling pathways

Learning and memory in adult females decline during menopause and estrogen replacement therapy is commonly prescribed during menopause. Post-menopausal women tend to suffer from depression and are prescribed antidepressants – in addition to hormone therapy. Estrogen replacement therapy is a topic that engenders debate since several studies contradict its efficacy as a palliative therapy for cognitive decline and neurodegenerative diseases. Signaling transduction pathways can alter brain cell activity, survival, and morphology by facilitating transcription factor DNA binding and protein production. The steroidal hormone estrogen and the anti-depressant drug lithium interact through these signaling transduction pathways facilitating transcription factor activation. The paucity of data on how combined hormones and antidepressants interact in regulating gene expression led me to hypothesize that in primary mixed brain cell cultures, combined 17β-estradiol (E2) and lithium chloride (LiCl) (E2/LiCl) will alter genetic expression of markers involved in synaptic plasticity and neuroprotection. Results from these studies indicated that a 48 h treatment of E2/LiCl reduced glutamate receptor subunit genetic expression, but increased neurotrophic factor and estrogen receptor genetic expression. Combined treatment also failed to protect brain cell cultures from glutamate excitotoxicity. If lithium facilitates protein signaling pathways mediated by estrogen, can lithium alone serve as a palliative treatment for post-menopause? This question led me to hypothesize that in estrogen-deficient mice, lithium alone will increase episodic memory (tested via object recognition), and enhance expression in the brain of factors involved in anti-apoptosis, learning and memory. I used bilaterally ovariectomized (bOVX) C57BL/6J mice treated with LiCl for one month. Results indicated that LiCl-treated bOVX mice increased performance in object recognition compared with non-treated bOVX. Increased performance in LiCl-treated bOVX mice coincided with augmented genetic and protein expression in the brain. Understanding the molecular pathways of estrogen will assist in identifying a palliative therapy for menopause-related dementia, and lithium may serve this purpose by acting as a selective estrogen-mediated signaling modulator.

An investigation of multiple pathways of developmental intervention change

Convergence among treatment, prevention, and developmental intervention approaches has led to the recognition of the need for evaluation models and research designs that employ a full range of evaluation information to provide an empirical basis for enhancing the efficiency, efficacy, and effectiveness of prevention and positive development interventions. This study reports an investigation of a positive youth development program using an Outcome Mediation Cascade (OMC) evaluation model, an integrated model for evaluating the empirical intersection between intervention and developmental processes. The Changing Lives Program (CLP) is a community supported positive youth development intervention implemented in a practice setting as a selective/indicated program for multi-ethnic, multi-problem at risk youth in urban alternative high schools. This study used a Relational Data Analysis integration of quantitative and qualitative data analysis strategies, including the use of both fixed and free response measures and a structural equation modeling approach, to construct and evaluate the hypothesized OMC model. Findings indicated that the hypothesized model fit the data (χ2 (7) = 6.991, p = .43; RMSEA = .00; CFI = 1.00; WRMR = .459). Findings also provided preliminary evidence consistent with the hypothesis that in addition to having effects on targeted positive outcomes, PYD interventions are likely to have progressive cascading effects on untargeted problem outcomes that operate through effects on positive outcomes. Furthermore, the general pattern of findings suggested the need to use methods capable of capturing both quantitative and qualitative change in order to increase the likelihood of identifying more complete theory informed empirically supported models of developmental intervention change processes.

A developmental intervention science outreach research approach to promoting positive youth development

Recent intervention efforts in promoting positive identity in troubled adolescents have begun to draw on the potential for an integration of the self-construction and self-discovery perspectives in conceptualizing identity processes, as well as the integration of quantitative and qualitative data analytic strategies. This study reports an investigation of the Changing Lives Program (CLP), using an Outcome Mediation (OM) evaluation model, an integrated model for evaluating targets of intervention, while theoretically including a Self-Transformative Model of Identity Development (STM), a proposed integration of self-discovery and self-construction identity processes. This study also used a Relational Data Analysis (RDA) integration of quantitative and qualitative analysis strategies and a structural equation modeling approach (SEM), to construct and evaluate the hypothesized OM/STM model. The CLP is a community supported positive youth development intervention, targeting multi-problem youth in alternative high schools in the Miami Dade County Public Schools (M-DCPS). The 259 participants for this study were drawn from the CLP’s archival data file. The model evaluated in this study utilized three indices of core identity processes (1) personal expressiveness, (2) identity conflict resolution, and (3) informational identity style that were conceptualized as mediators of the effects of participation in the CLP on change in two qualitative outcome indices of participants’ sense of self and identity. Findings indicated the model fit the data (χ2 (10) = 3.638, p = .96; RMSEA = .00; CFI = 1.00; WRMR = .299). The pattern of findings supported the utilization of the STM in conceptualizing identity processes and provided support for the OM design. The findings also suggested the need for methods capable of detecting and rendering unique sample specific free response data to increase the likelihood of identifying emergent core developmental research concepts and constructs in studies of intervention/developmental change over time in ways not possible using fixed response methods alone.

Endocrine regulation of dynamic communication signals in gymnotiform fish

Communication signals are shaped by the opposing selection pressures imposed by predators and mates. A dynamic signal might serve as an adaptive compromise between an inconspicuous signal that evades predators and an extravagant signal preferred by females. Such a signal has been described in the gymnotiform electric fish, Brachyhypopomus gauderio, which produces a sexually dimorphic electric organ discharge (EOD). The EOD varies on a circadian rhythm and in response to social cues. This signal plasticity is mediated by the slow action of androgens and rapid action of melanocortins. My dissertation research tested the hypotheses that (1) signal plasticity is related to sociality levels in gymnotiform species, and (2) differences in signal plasticity are regulated by differential sensitivity to androgen and melanocortin hormones. To assess the breadth of dynamic signaling within the order Gymnotiformes, I sampled 13 species from the five gymnotiform families. I recorded EODs to observe spontaneous signal oscillations after which I injected melanocortin hormones, saline control, or presented the fish with a conspecific. I showed that through the co-option of the ancient melanocortin pathway, gymnotiforms dynamically regulate EOD amplitude, spectral frequency, both, or neither. To investigate whether observed EOD plasticities are related to species-specific sociality I tested four species; two territorial, highly aggressive species, Gymnotus carapo and Apteronotus leptorhynchus, a highly gregarious species, Eigenmannia cf. virescens , and an intermediate short-lived species with a fluid social system, Brachyhypopomus gauderio. I examined the relationship between the androgens testosterone and 11-ketotestosterone, the melanocortin α-MSH, and their roles in regulating EOD waveform. I implanted all fish with androgen and blank silicone implants, and injected with α-MSH before and at the peak of implant effect. I found that waveforms of the most territorial and aggressive species were insensitive to hormone treatments; maintaining a static, stereotyped signal that preserves encoding of individual identity. Species with a fluid social system were most responsive to hormone treatments, exhibiting signals that reflect immediate condition and reproductive state. In conclusion, variation in gymnotiform signal plasticity is hormonally regulated and seems to reflect species-specific sociality.

On the developmental continuity /discontinuity of early adolescent patterns of racial identity salience: Relations with later identities and psychosocial adjustment

Given the significant amount of attention placed upon race within our society, racial identity long has been nominated as a meaningful influence upon human development (Cross, 1971; Sellers et al., 1998). Scholars investigating aspects of racial identity have largely pursued one of two lines of research: (a) describing factors and processes that contribute to the development of racial identities, or (b) empirically documenting associations between particular racial identities and key adjustment outcomes. However, few studies have integrated these two approaches to simultaneously evaluate developmental and related adjustment aspects of racial identity among minority youth. Consequently, relations between early racial identity developmental processes and correlated adjustment outcomes remain ambiguous. Even less is known regarding the direction and function of these relationships during adolescence. To address this gap, the present study examined key multivariate associations between (a) distinct profiles of racial identity salience and (b) adjustment outcomes within a community sample of African-American youth. Specifically, a person-centered analytic approach (i.e., cluster analysis) was employed to conduct a secondary analysis of two archived databases containing longitudinal data measuring levels of racial identity salience and indices of psychosocial adjustment among youth at four different measurement occasions.^ Four separate groups of analyses were conducted to investigate (a) the existence of within-group differences in levels of racial identity salience, (b) shifts among distinct racial identity types between contiguous times of measurement, (c) adjustment correlates of racial identity types at each time of measurement, and (d) predictive relations between racial identity clusters and adjustment outcomes, respectively. Results indicated significant heterogeneity in patterns of racial identity salience among these African-American youth as well as significant discontinuity in the patterns of shifts among identity profiles between contiguous measurement occasions. In addition, within developmental stages, levels of racial identity salience were associated with several adjustment outcomes, suggesting the protective value of high levels of endorsement or internalization of racial identity among the sampled youth. Collectively, these results illustrated the significance of racial identity salience as a meaningful developmental construct in the lives of African-American adolescents, the implications of which are discussed for racial identity and practice-related research literatures. ^

Ethnic and American identity development: A developmental systems approach

Given the role ethnic identity has as a protective factor against the effects of marginalization and discrimination (Umaña-Taylor, 2011), research longitudinally examining ethnic identity has become of increased importance. However, successful identity development must incorporate elements from both one's ethnic group and from the United States (Berry, 1980). Despite this, relatively few studies have jointly evaluated ethnic and American identity (Schwartz et al., 2012). The current dissertation, guided by three objectives, sought to address this and several other gaps in the literature. First, psychometric properties of the Multigroup Ethnic Identity Measure (MEIM) and the American Identity Measure (AIM) were evaluated. Secondly, the dissertation examined growth trends in recently immigrated Hispanic adolescents' and their caregivers' ethnic and American identity. Lastly, the relationship between adolescents' and caregivers' ethnic and American identity was evaluated. The study used an archival sample consisting of 301 recently immigrated Hispanic families collected from Miami (N = 151) and Los Angeles (N = 150). Consistent with previous research, results in Study 1 indicated a two-factor model reliably provided better fit than a one-factor model and established longitudinal invariance for the MEIM and the AIM. Results from Study 2 found significant growth in adolescents' American identity. While some differences were found across site and nationality, evidence suggested recently immigrated Hispanic adolescents were becoming more bicultural. Counterintuitively, results found a significant decline in caregivers' ethnic identity which future studies should further examine. Finally, results from Study 3, found several significant positive relationships between adolescents' and their caregivers' ethnic and American identity. Findings provided preliminary evidence for the importance of examining identity development within a systemic lens. Despite several limitations, these three studies represented a step forward in addressing the current gaps in the cultural identity literature. Implications for future investigation are discussed.

The influence of perception of forgetting and gender, ethnicity, and closeness on likelihood of caregiving

As life expectancy increases, the population of older adults is increasing rapidly. The caregiving of older parents by adult children has become a normative experience. Much of the gerontological literature has examined the caregiving experience, particularly in terms of the stresses involved. However, research is only beginning to examine the factors which motivate adult children to begin caregiving. The research described here examined how an elderly parent's memory behavior might influence caregiving decisions. In addition, gender, ethnicity, and parent-adult child closeness were examined to explore how these individual difference variables might influence those caregiving decisions.^ Participants read one of two vignettes describing a social visit with an elderly widow (target). In the vignette, the elderly target experiences several instances of forgetting. The vignettes depicted forgetting behavior established in pilot work as normal or serious. The normal forgetting vignette did not arouse concern and the serious forgetting vignette did arouse concern when the middle-aged participants imagined their mothers in the role of the vignette target. Participants rated their likelihood of engaging in eight caregiving behaviors if their mothers behaved like the vignette target. They also rated their closeness with their own mothers.^ Multivariate analyses of variance indicated main effects for vignette type, gender, ethnicity, and attachment. The likelihood of caregiving was higher when forgetting was more serious and when participants were female, Hispanic, and were highly attached to their mothers. Interaction effects showed that gender differences decreased with increased seriousness of forgetting, and ethnic differences were only significant for the normal forgetting condition.^ Multiple regression analyses indicated that attachment was the most significant predictor of likelihood of caregiving. Gender and ethnicity predicted specific caregiving behaviors. Females were more likely to engage in phoning and cooking, and Hispanics were more likely to engage in visiting and suggesting mother move in. ^

Patterns of diagnostic comorbidity in children and adolescents with anxiety

Comorbidity is defined as the co-occurrence of two or more psychological disorders and has been identified as one of the most pressing issues facing child psychologists today. Unfortunately, research on comorbidity in anxious children is rare. The purpose of this research was to examine how specific comorbid patterns in children and adolescents referred with anxiety disorders affected clinical presentation. In addition, the effects of gender, age and total number of diagnoses were also examined.^ Three hundred fifty-five children and adolescents (145 girls and 210 boys, hereafter referred to as "children") aged 6 to 17 who presented to the Child Anxiety and Phobia Program during the years 1987 through 1996 were assessed through a structured clinical interview administered to both the children and their families. Based on information from both children and parents, children were assigned up to five DSM diagnoses. Global ratings of severity were also obtained. While children were interviewed, parents completed a number of questionnaires pertaining to their child's overall functioning, anxiety, thoughts and behaviors. Similarly, while parents were interviewed, children completed a number of self-report questionnaires concerning their own thoughts, feelings and behaviors.^ In general, children with only anxiety disorders were rated as severe as children who met criteria for both anxiety and externalizing disorders. Children with both anxiety and externalizing disorders were mostly young (i.e. age 6 through 11) and mostly male. These children tended to rate themselves (and be rated by their parents) equally as anxious as children with only anxiety disorders. Global ratings of severity tended to be associated with the type of comorbid pattern versus the number of diagnoses assigned to a child. The theoretical, development and clinical implications of these findings will be discussed. ^

The influence of weak parental and peer attachment on academic achievement among late adolescent college students

The current study examined the influence of weak parental and peer attachment on academic achievement among late adolescent college students. In previous research, weak attachment to parents and/or peers had been found to have an adverse influence on the academic success of college students. This study also examined the potential moderating influence of several cognitive and non-cognitive psychosocial variables that might act as protective factors for weakly attached students and, therefore, enhance their academic competence. Data regarding attachment, cognitive variables, and non-cognitive variables were collected using several self-report measures. The multi-ethnic sample of students in this study (n = 357) attended an urban university. Students were classified into one of nine parental-peer attachment groups (e.g., Low-Low, Medium-Medium, High-High). Attachment groups were compared in terms of cognitive and non-cognitive variables. Contrary to the hypothesis, no statistically significant academic achievement differences were revealed for the group of college students who perceived themselves to be weakly attached to both parents and peers. Analysis of variance (ANOVA) identified the High-High group to be significantly different in terms of academic outcome variables from the other eight groups while the Low-Low group had significantly lower levels of non-cognitive variables than several of the other attachment groups. Hierarchical multiple regression analyses revealed that cognitive variables accounted for significant amounts of variance in academic outcomes and that several non-cognitive variables were significant predictors of scholastic competence. Correlational analyses revealed that parental and peer attachment were positively correlated with several cognitive and non-cognitive variables but neither was significantly correlated with self-reported college GPA. In general, the findings do not provide support for a main effect of weak attachment to parents and peers upon academic adversity among college students. Results suggest that both cognitive variables and non-cognitive variables may moderate academic risk due to weak attachment to parents and peers. Descriptive within group analyses of the Low-Low group revealed a heterogeneous group of students with regards to academic outcomes and scores on non-cognitive measures. Gender and ethnic differences were found for attachment status but not for cognitive or non-cognitive variables. Implications for interventions and suggestions for future research are presented. ^

Perceptions of family environment, body image and self-esteem of eating disordered and non-eating disordered women

This study explored the perceptions of family environment, body image and self esteem of women who suffer from anorexia nervosa, bulimia nervosa, and depression. Using a nonequivalent control group design, one hundred and fifty women with anorexia nervosa (n = 50), bulimia nervosa (n = 50), and depression (n = 50) were given the Family Environment Scale (FES) and the Eating Disorders Inventory-2 (EDI-2). The objectives of this study were to: (1) study how women with anorexia nervosa and bulimia nervosa perceive their family environment as measured by the FES; (2) compare and contrast perceptions of family environment of women with anorexia nervosa and bulimia nervosa with the control group; (3) compare and contrast perceived levels of self esteem and body image as measured by the EDI-2 of women with anorexia nervosa and bulimia nervosa with the control group; and (4) examine the perceived family environments of eating disordered and non-eating disordered women with regard to body image and self esteem. Results suggested, women who suffered from anorexia nervosa or bulimia nervosa scored significantly lower (p $<$.021) on the Expressiveness, Intellectual-Cultural Orientation, and Active-Recreational subscales of the FES. The results also indicated that women who suffered from bulimia nervosa scored significantly higher (p $<$.015) than women who suffered from anorexia nervosa on the Conflict and Independence subscales of the FES. The results of studying these three populations reflected that women who suffered from anorexia nervosa scored significantly different (p $<$.000) than women who suffered from bulimia nervosa on many of the subscales of the EDI-2. The findings of the study confirmed that women who suffered from anorexia nervosa or bulimia nervosa scored significantly different (p $<$.000) on the subscales of the EDI-2 compared to women who suffered from depression. It was also confirmed that a relationship does exist between perceptions of body image and self esteem and perceptions of family environment amongst women with anorexia nervosa and bulimia nervosa as compared to depressed women. The findings of the study indicated that women who suffered from anorexia nervosa tended to: be less expressive and independent; handle conflict less openly; have a greater drive for thinness; have greater body dissatisfaction; be more perfectionistic; and struggle more intensely with fears around maturity and social insecurity than did women who suffered from bulimia nervosa or depression. In addition, the findings of the study also suggested that women who suffered from bulimia nervosa tended to: be raised in homes where openly expressed anger is permitted amongst family members; have a lesser drive for thinness; have less body dissatisfaction; be less perfectionistic; and not struggle as intensely with fears around maturity and social insecurity as do women who suffered from anorexia nervosa, but more than women who suffer from depression. Treatment implications that may assist community college professors and counselors in meeting the special needs of this special group of women were also discussed. (Abstract shortened by UMI.) ^

The role of exploration and critical decision making and problem solving in making life choices

Although the literature on the types of abilities and processes that contribute to identity formation has been growing, the research has been mainly descriptive/correlational. This dissertation conducted an experimental investigation of the role of two theoretically distinct processes (exploration and critical problem solving) in identity formation, one of the first to be reported. The experimental training design (pre-post, training versus control) used in this study was intended to promote identity development by fostering an increase in the use of exploration and critical problem solving with respect to making life choices. Participants included 53 psychology students from a large urban university randomly assigned to each group. The most theoretically significant finding was that the intervention was successful in inducing change in the ability to use critical skills in resolving life decisions, as well as effecting a positive change in identity status. ^