Charting developmental EEG gamma changes in the auditory modality /

The oscillation of neuronal circuits reflected in the EEG gamma frequency may be fundamental to the perceptual process referred to as binding (the integration of various thoughts and perceptions into a coherent picture). The aim of our study was to expand our knowledge of the developmental course ofEEG gamma in the auditory modality. 2 We investigated EEG 40 Hz gamma band responses (35.2 to 43.0 Hz) using an auditory novelty oddball paradigm alone and with a visual-number-series distracter task in 208 participants as a function of age (7 years to adult) at 9 sites across the sagital and lateral axes (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4). Gamma responses were operationally defined as change in power or a change in phase synchrony level from baseline within two time windows. The evoked gamma response was defined as a significant change from baseline occurring between 0 to 150 ms after stimulus onset; the induced gamma response was measured from 250 to 750 ms after stimulus onset. A significant evoked gamma band response was found when measuring changes in both power and phase synchrony. The increase in both measures was maximal at frontal regions. Decreases in both measures were found when participants were distracted by a secondary task. For neither measure were developmental effects noted. However, evoked gamma power was significantly enhanced with the presentation of a novel stimulus, especially at the right frontal site (F4); frontal evoked gamma phase synchrony also showed enhancement for novel stimuli but only for our two oldest age groups (16-18 year olds and adults). Induced gamma band responses also varied with task-dependent cognitive stimulus properties. In the induced gamma power response in all age groups, target stimuli generated the highest power values at the parietal region, while the novel stimuli were always below baseline. Target stimuli increased induced synchrony in all regions for all participants, but the novel stimulus selectively affected participants dependent on their age and gender. Adult participants, for example, exhibited a reduction in gamma power, but an increase in synchrony to the novel stimulus within the same region. Induced gamma synchrony was more sensitive to the gender of the participant than was induced gamma power. While induced gamma power produced little effects of age, gamma synchrony did have age effects. These results confirm that the perceptual process which regulates gamma power is distinct from that which governs the synchronization for neuronal firing, and both gamma power and synchrony are important factors to be considered for the "binding" hypothesis. However, there is surprisingly little effect of age on the absolute levels of or distribution of EEG gamma in the age range investigated.

Developmental patterns of individiuals within a sensory-based learning environment in art education : insights emerging from a case study /

My research permitted me to reexamine my recent evaluations of the Leaf Project given to the Foundation Year students during the fall semester of 1997. My personal description of the drawing curriculum formed part of the matrix of the Foundation Core Studies at the Ontario College of Art and Design. Research was based on the random selection of 1 8 students distributed over six of my teaching groups. The entire process included a representation of all grade levels. The intent of the research was to provide a pattern of alternative insights that could provide a more meaningful method of evaluation for visual learners in an art education setting. Visual methods of learning are indeed complex and involve the interplay of many sensory modalities of input. Using a qualitative method of research analysis, a series of queries were proposed into a structured matrix grid for seeking out possible and emerging patterns of learning. The grid provided for interrelated visual and linguistic analysis with emphasis in reflection and interconnectedness. Sensory-based modes of learning are currently being studied and discussed amongst educators as alternative approaches to learning. As patterns emerged from the research, it became apparent that a paradigm for evaluation would have to be a progressive profile of the learning that would take into account many of the different and evolving learning processes of the individual. A broader review of the student's entire development within the Foundation Year Program would have to have a shared evaluation through a cross section of representative faculty in the program. The results from the research were never intended to be conclusive. We realized from the start that sensory-based learning is a difficult process to evaluate from traditional standards used in education. The potential of such a process of inquiry permits the researcher to ask for a set of queries that might provide for a deeper form of evaluation unique to the students and their related learning environment. Only in this context can qualitative methods be used to profile their learning experiences in an expressive and meaningful manner.

An international investigation on the validity of the CSAPPA scale in screening for developmental coordination disorder /

The main objective of the present investigation was to continue the research initiated by Hay and colleagues (2004) in examining the efficacy of the Children's Self-Perceptions of Adequacy in and Predilection for Physical Activity (CSAPPA) scale as a proxy for the short form of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP-SF) in screening for Developmental Coordination Disorder (DCD) in children. To better appreciate DCD knowledge outside Canada, the measurements of this investigation were expanded in Greece. A translated Greek CSAPP A scale and the BOTMP-SF were administered for the first time in Greek children. A second objective was to investigate the relationship between DCD and various risk factors of coronary artery disease (CAD) in Canadian and Greek children. A sample of 591 (Ms=322; Fs=269) Canadian and 392 (Ms=211; Fs=181) Greek children, aged 9 to 13 years, consented to the BOTMP-SF, CSAPP A Scale, participation in physical activity questionnaire, Leger 20-meter Multistage Shuttle Run test, and body fat using bioelectric impedance. Prevalence of DCD in Canada and Greece was 8% and 19%, respectively. Significant agreement (p

Mermithid (nematoa: mermithidae) infections of black flies (Diptera: Simuliidae) : seasonal variation and developmental characteristics /

Mermithid nematodes (Nematoda: Mermithidae) parasitize larval, pupal and adult black flies (Diptera: Simuliidae), oftentimes resulting in partial or complete host feminization. This study was designed to characterize parasite-host seasonal variation and to estabUsh the developmental life stage at which feminization is initiated. Data indicate that the total adult population of black flies collected from Algonquin Provincial Park throughout the spring of 2004 was comprised of 31.8% female, 67.8% male and 0.4% intersex individuals. Of the total population, 0.6% was infected by mermithid nematodes (69.0% female, 3.5% male and 27.6% intersex). Seasonal infection trends established over a 12-month period revealed that black flies with different life histories host the same mermithid subfamilies, while black flies with similar life histories host mermithids from different subfamilies. If a simuliid species simultaneously hosts two mermithid species, these parasites are from different subfamilies. Molecular mermithid identification revealed two mermithid subfamilies, Me.somermithinae and Gastromermithinae, present in the simuliid hosts. Mermithid colour variation was not found to be a reliable species indicator. The developmental stage at which feminization is initiated was determined by examining gonad morphology and meiotic chromosomal condition. Results indicate that mermithid-infected black flies exhibit feminization prior to larval histoblast formation. Larvae can be morphologically male (testes present) or female (ovaries present), with morphological males exhibiting either male (achiasmate) or female (chiasmate) meiotic chromosomes; morphological females were only genetically female. Additionally, mermithid infection inhibits simuliid gonad development.

Developmental variations in the peripheral erythrocytic system of the rainbow trout, Salmo gairdneri

The peripheral circulating erythrocytic system of the rainbow trout, l3 almo gairdner , was examined in vitro in relation differences in the morphology and multiple hemoglobin system organization of adult and juvenile red cells. Cells were separated by velocity sedimentation under unit gravity, a procedure requiring red cell exposure to an incubation medium for periods of at least three hours. Therefore , this must provide an environment in which red cells remain in a condition approximaing normalcy. Previous studies having demonstrated commonly employed media to be ineffective in this regard , a medium was developed through modification of Cortl and saline. One of the principal additions to this me dium , norepinephrine, altered cell regulation of intracellular calcium, magnesium and chloride concentrations. Catecholamine involvement was also suggeste d in the synthes is of hemoglobin . The procedure was found to separtate cells primarily by density and, to a lesser extent, by shape. Characterization of red cells revealed two subpopulations to exist . The first comprised the bulk of the cell population, and were of greater l ength, width, volume and major:minor axis ratio than the smaller population; these were adult cells. The later, juvenile cells were of smaller overall size and were more spherical in shape . Juvenile cells also possessed fewer electrophore tpically distinguishable isomorphs than did adults with only eight of eleven hemoglobin component s typically found With maturation,hemoglobin complement with the development of three more bands. The total complement of the adult cell contained 7 cathodal bands and four anodal hemoglobin isomorphs. Bands acquired with maturation comprised the smallest percentage of the cells hemoglobin. each averaging less than one-percent of the total. Whether these additional bands are derived through degradation and reaggregation of existing components or are the product of pe gQy2 synthesis is not yet known.

School integration and the friendships of youth with developmental disabilities

- The present study was an investigation into the effect ofschool integration on the friendships ofyouth with developmental disabilities and their peers without disabilities. The youths, their parents, and their teachers provided insights into the youths' friendships. A qualitative paradigm was used in this research. The researcher guided the collection and analysis ofthe data with the phenomenologicallifeworld existentials of body, space, time, and human relation (Van Manen, 1990). Individual interviews were conducted with each youth, and group interviews were conducted with each triad (a youth, their parent(s), and their teacher) to discuss the youth's friendships and the supports necessary to facilitate the friendships. Through phenomenological analysis of the data, four thematic statements emerged: friendships are far from perfect, to have a friend you have to be a friend, parents as choreographers offriendship, and teachers as reluctant partners in friendship facilitation. Based on the results ofthis study, it was concluded that the development of friendships between youth with developmental disabilities and their peers without disabilities was happening in integrated school settings. However, it was also evident that the support ofteachers and parents alike were required to facilitate the development and maintenance ofsuch friendships. Recommendations for practice are discussed, including the need for active participation by the youth's parents in the facilitation offriendships, and the use ofa "circle offriends" to facilitate friendship development. Also discussed are the recommendations for further research, including the need for the youth's friends to be interviewed regarding their friendships with the youth with disabilities, and the need for researcher observation ofth~ friendships in action. Further research could also explore the role ofthe mother versus the father in facilitating friendships, and the role of recreation and leisure opportunities in the ,development offriendships.

Sex education for individuals who have a developmental disability : the need for assessment

This study was an evaluation of the sexual knowledge of individuals who have '"a developmental disability and the effect of sex education. This was also a pilot study involving the evaluation of the Socio-Sexual Knowledge and Attitudes Assessment Tool (SSKAAT; Griffiths & Lunsky, in press). This tool is a revised version of the Socio-Sexual Knowledge and Attitudes Test (SSKAT; Wish, Fiechtl McCombs, & Edmonson, 1980). Thirty-two individuals participated in the study (20 males and 12 females), who were receiving supports from local community agencies. Participants were assessed using the SSKAAT and SSKAT in an initial assessment and in a 6-week follow-up. Sixteen participants received a 6-week sex education program, Life Horizons I and II (Kempton & Stanfield, 1988a, 1988b), between the assessments, while 16 participants served as a control group. It was found that sex education was successful at increasing knowledge regarding sexuality, as demonstrated by increased scores on both the SSKAT and SSKAAT. However, the current study did not demonstrate any significant effect of gender on knowledge about sexuality. It was also found that IQ did not have a significant effect on knowledge regarding sexuality. The present study found the SSKAAT to be very reliable, with test-retest reliabilities ranging from .87 to .99. This appeared to be an improvement over the original SSKAT, whose reliability ranged from .72 to .90. Furthennore, the revised SSKAAT was fOlmd to provide a much more in-depth assessment of sexual knowledge and attitudes for individuals who have a developmental disability.

Developmental and individual differences in novelty and error detection in 10-year-old children and young adults /

Event-related potentials were recorded from 10-year-old children and young adults in order to examine the developmental dififerences in two frontal lobe functions: detection of novel stimuli during an auditory novelty oddball task, and error detection during a visual flanker task. All participants showed a parietally-maximal P3 in response to auditory stimuli. In children, novel stimuli generated higher P3 amplitudes at the frontal site compared with target stimuli, whereas target stimuli generated higher P3 amplitudes at the parietal site compared with novel stimuli. Adults, however, had higher P3 amplitude to novel tones compared with target tones at each site. Children also had greater P3 amplitude at more parietal sites than adults during the novelty oddball and flanker tasks. Furthermore, children and adults did not show a significant reduction in P3 amplitude from the first to second novel stimulus presentation. No age differences were found with respect to P3 latency to novel and target stimuli. These findings suggest that the detection of novel and target stimuli is mature in 10-year-olds. Error trials typically elicit a negative ERP deflection (the ERN) with a frontal-central scalp distribution that may reflect response monitoring. There is also evidence of a positive ERP peak (the Pe) with a posterior scalp distribution which may reflect subjective recognition of a response. Both children and adults showed an ERN and Pe maximal at frontal-central sites. Children committed more errors, had smaller ERN across sites, and had a larger Pe at the parietal site than adults. This suggests that response monitoring is still immature in 10-year-olds whereas recognition of and emotional responses to errors may be similar in children and adults.

Physical activity of children with developmental coordination disorder in the presence of attention deficit hyperactivity disorder : does gender matter?

Baerg, S., Cairney, J., Hay, J., Rempel, L. and Faught, B.E. (2009). Physical Activity of Children with Developmental Coordination Disorder in the Presence of Attention Deficit Hyperactivity Disorder: Does Gender Matter? Brock University, St. Catharines, Ontario, CANADA. Children with Developmental Coordination Disorder (DCD) have difficulties in motor coordination. Attention-deficit hyperactive disorder (ADHD) is considered the condition most co-morbid with DCD at approximately 50%. Children with DCD are generally less physically active (PA) than their peers, while children with ADHD are often considered more physically active. It is not known if the physical activity patterns of children with DCD-ADHD resemble those of children with primarily DCD or that of their healthy peers. The primary objective of this research was to contrast physical activity patterns between children with DCD, DCD-ADHD, and healthy controls. Since boys are generally reported as more physically active than girls, a secondary objective was to determine if gender moderated the association between groups and physical activity. A sample of males (n=66) and females (n=44) were recruited from the Physical Health Activity Study Team (PHAST) longitudinal study. The Movement Assessment Battery for Children (2nd Ed.) was used to identify probable cases of DCD, and Connor's Revised Parent Rating Scale- Short Version to identify ADHD. Subjects (mean age=12.8±.4 yrs) were allocated to three groups; DCD (n=32), DCD-ADHD (n=30) and control (n=48). Physical activity was monitored for seven days with the Actical® accelerometer (activity count, step count and energy expenditure). Children completed the Participation Questionnaire (PQ) during the in-school session of data collection for the PHAST study. Height, weight and body mass index (BMI) were also determined. Analysis of variance showed significant group differences for activity count (F(2,56)=5.36, p=.007) and PQ (F(2,44 )=6. 71, p=.003) in males, while a significant group difference for step count (F(2,37)=3.55, p=.04) was found in females. Post hoc comparison tests (Tukey) identified significantly lower PQ and activity count between males with OCD and controls (p=.004) and males with DCD-ADHD and controls (p=.003). Conversely, females with DCD-ADHD had significantly more step counts than their controls (p=.01). Analysis of covariance demonstrated a gender by DCD groups negative interaction for males (activity count) (F(2,92):;:3.11, p=.049) and a positive interaction for females (step count) (F(1,92)=4.92, p=.009). Hyperactivity in females with DCD-ADHD appears to contribute to more physical activity, whereas DCD may contribute to decreased activity in males with DCD and DCDADHD. Further research is needed to examine gender differences in physical activity within the context of DCD and ADHD.

The role of physical activity and perceived adequacy on cardiorespiratory fitness in children with developmental coordination disorder

Evidence suggests that children with developmental coordination disorder (DCD) have lower levels of cardiorespiratory fitness (CRF) compared to children without the condition. However, these studies were restricted to field-based methods in order to predict V02 peak in the determination of CRF. Such field tests have been criticised for their ability to provide a valid prediction of V02 peak and vulnerability to psychological aspects in children with DCD, such as low perceived adequacy toward physical activity. Moreover, the contribution of physical activity to the variance in V02 peak between the two groups is unknown. The purpose of our study was to determine the mediating role of physical activity and perceived adequacy towards physical activity on V02 peak in children with significant motor impairments. This prospective case-control design involved 122 (age 12-13 years) children with significant motor impairments (n=61) and healthy matched controls (n=61) based on age, gender and school location. Participants had been previously assessed for motor proficiency and classified as a probable DCD (p-DCD) or healthy control using the movement ABC test. V02 peak was measured by a progressive exercise test on a cycle ergometer. Perceived adequacy was measured using a 7 -item subscale from Children's Selfperception of Adequacy and Predilection for Physical Activity scale. Physical activity was monitored for seven days with the Actical® accelerometer. Children with p-DCD had significantly lower V02 peak (48.76±7.2 ml/ffm/min; p:50.05) compared to controls (53.12±8.2 ml/ffm/min), even after correcting for fat free mass. Regression analysis demonstrated that perceived adequacy and physical activity were significant mediators in the relationship between p-DCD and V02 peak. In conclusion, using a stringent laboratory assessment, the results of the current study verify the findings of earlier studies, adding low CRF to the list of health consequences associated with DCD. It seems that when testing for CRF in this population, there is a need to consider the psychological barriers associated with their condition. Moreover, strategies to increase physical activity in children with DCD may result in improvement in their CRF.

Left ventricular structure in children with developmental coordination disorder

Developmental coordination disorder (p-DCD) is a neuro-developmental disorder featuring impairment in developing motor coordination. This study examined left ventricular mass (LVM) in children with p-DCD (n=63) and controls (n=63). LVM was measured using echocardiography. Body composition was determined using BOD POD and peak oxygen uptake (peak V02) was measured by a progressive exercise test. Height, weight and blood pressure were also measured. LVM was not significantly elevated in p-DCD compared to controls. Peak V02 was lower and SBP, BMI, HR, and BF(%) were significantly higher in p-DCD. They also demonstrated elevated stroke volume (SV), cardiac output (CO), end-diastolic volume, and ventricular diameter in diastole. In regression analyses, p-DCD was a significant predictor of SV and CO after accounting for height, FFM, V02FFM, and sex. These differences in children with p-DCD indicate obesity related changes in the left ventricle and may represent early stages of developing hypertrophy of the left ventricle.

Baroreflex sensitivity and developmental coordination disorder

Developmental coordination disorder (DCD) is a motor coordination disorder that is characterized by impairment of motor skills which leads to challenges with performing activities of daily living. Children with DCD have been shown to be less physically active and have increased body fatness. This is an important finding since a sedentary lifestyle and obesity are risk factors for cardiovascular disease. One indicator of cardiovascular health is baroreflex sensitivity (BRS), which is a measure of short term BP regulation that is accomplished through changes in HR. Diminished BRS is predictive of cardiovascular morbidity and mortality. The purpose of this study was to investigate BRS in 117 children aged 12 to 13 years with probable DCD (pOCO) and their matched controls with normal coordination. Following 15 minutes of supine rest, five minutes of continuous beat-by-beat blood pressure (Finapres) and RR interval were recorded (standard ECG). Spectral indices were computed using Fast Fourier Transform and transfer function analysis was used to compute BRS. High frequency and low frequency power spectral areas were set to 0.15-0.6 Hz and 0.04-0.15 Hz, respectively. BRS was compared between groups with an independent t-test and the difference was not significant. It is likely that a difference in BRS was not seen between groups since the difference in BMI between groups was small. As well, differences in BRS may not have manifested yet at this early age. However, the cardiovascular health of this population still deserves attention since differences in body composition and fitness were found between groups.

Developmental differences in locomotor responsiveness to amphetamine in rats

The developmental remodelling of motivational systems that underlie drug dependence and addiction may account for the greater frequency and severity of drug abuse in adolescence compared to adulthood. Recent advances in animal models have begun to identify the morphological and the molecular factors that are being remodelled, but little is known about the culmination of these factors in altered sensitivity to psycho stimulant drugs, like amphetamine, in adolescence. Amphetamine induces potent locomotor activating effects in rodents through increased dopamine release in the mesocorticolimbic dopamine system, which makes locomotor activity a useful behavioural marker of age differences in amphetamine sensitivity. The aim of the thesis was to investigate the neural basis for age differences in amphetamine sensitivity with a focus on the nucleus accumbens and the medial prefrontal cortex, which initiate and regulate amphetamine-induced locomotor activity, respectively. In study 1, I found pre- and post- pubertal adolescent rats to be less active (i.e., hypoactive) than adults to a first injection of 0.5, but not of 1.5, mg/kg of intraperitonealy (i.p.) administered amphetamine. Although initially hypoactive, only adolescent rats exhibited an increase in activity to a second injection of amphetamine given 24 h later, indicating that adolescents may be more sensitive to the rapid changes in amphetamineinduced plasticity than adults. Given that the locomotor activating effects of amphetamine are initiated in the nucleus accumbens, age differences in response to direct injections of amphetamine into this brain region were investigated in study 2. In contrast to i.p. injections, adolescents were more active than adults when amphetamine was given directly into the nucleus accumbens, indicating that hypo activity may be attributed to the development of regulatory regions outside of the accumbens. The medial prefrontal cortex (mPFC) is a key regulator of the locomotor activating effects of amphetamine that undergoes extensive remodelling in adolescence. In study 3, I found that an i.p. injection of 1.5, and not of 0.5, mg/kg of amphetamine resulted in a high expression of c-fos, a marker of neural activation, in the pre limbic mPFC only in pre-pubertal adolescent rats. This finding suggests that the ability of adolescent rats to overcome hypo activity at the 1.5 mg/kg dose may involve greater activation of the prelimbic mPFC compared to adulthood. In support of this hypothesis, I found that pharmacological inhibition of prelimbic D 1 dopamine receptors disrupted the locomotor activating effects of the 1.5 mg/kg dose of amphetamine to a greater extent in adolescent than in adult rats. In addition, the stimulation of prelimbic D 1 dopamine receptors potentiated locomotor activity at the 0.5 mg/kg dose of amphetamine only in adolescent rats, indicating that the prelimbic D1 dopamine receptors are involved in overcoming locomotor hypoactivity during adolescence. Given my finding that the locomotor activating effects of amphetamine rely on slightly different mechanisms in adolescence than in adulthood, study 4 was designed to determine whether the lasting consequences of drug use would also differ with age. A short period of pre-treatment with 0.5 mg/kg of amphetamine in adolescence, but not in adulthood, resulted in heightened sensitivity to an injection of amphetamine given 30 days after the start of the procedure, when adolescent rats had reached adulthood. The finding of an age-specific increase in amphetamine sensitivity is consistent with evidence for increased risk for addiction when drug use is initiated in adolescence compared to adulthood in people (Merline et aI., 2002), and with the hypothesis that adolescence is a sensitive period of development.

Family attitudes toward the deinstitutionalization of individuals with developmental disabilities in Ontario : a quality of life analysis

The deinstitutionalization of individuals with developmental disabilities to community-based residential services is a pervasive international trend. Although controversial, the remaining three institutions in Ontario were closed in March of 2009. Since these closures, there has been limited research on the effects of deinstitutionalization. The following retrospective study evaluated family perceptions of the impact of deinstitutionalization on the quality of life of fifty-five former residents one year post-closure utilizing a survey design and conceptual quality of life framework. The methods used to analyze the survey results included descriptive statistical analyses and thematic analyses. Overall, the results suggest that most family members are satisfied with community placement and supports, and report an improved quality of life for their family member with a developmental disability. These findings were consistent with previously published studies demonstrating the short-term and long-term benefits of community living for most individuals with developmental disabilities and their families.

Physical Activity and Fitness in Children with Developmental Disorder

Introduction: Developmental coordination disorder (DCD) is a prevalent condition characterized by poor motor proficiency that interferes with a child‟s activities of daily living. Children with DCD often experience compromised health-related fitness components such as cardiorespiratory fitness (CRF). Purpose: To better understand the physical activity and fitness characteristics of children with probable DCD (pDCD), with a particular focus on CRF. Specifically: (1) to present a synopsis of current literature; (2) to determine the longitudinal trajectories of CRF; (3) to compare the submaximal CRF of children with and without pDCD. Methods: A comprehensive, systematic literature review was conducted of the recent available data on fitness and physical activity and pDCD (Chapter 2). This review provided the background for the other two studies included in this thesis. In Chapter 3, a prospective cohort design was used to assess how CRF in children with pDCD changes over time (56 months) relative to a group of typically developing controls. Using a nested-case control design, 63 subjects with pDCD and 63 matched controls from the larger sample were recruited to participate in the lab-based component of the study (Chapter 4). In this investigation CRF was examined using the oxygen cost of work (VO2) during an incremental test on a cycle ergometer. Results: The literature review showed that fitness parameters, including CRF and physical activity levels, were consistently reduced in children with pDCD. Chapter 3 demonstrated that the difference in CRF between children with pDCD and typically developing children is substantial, and that it tends to increase over time. Results from VO2 assessments showed that children with pDCD utilized more oxygen to sustain the same submaximal workloads compared to typically developing children. Conclusions: Findings from this thesis have made several important contributions to our understanding of children with pDCD. Since differences in CRF between children with and without pDCD tend to worsen over time, this adds to the argument that interventions intended to improve CRF may be appropriate for children with motor difficulties. This thesis also presented the first evidence suggesting that DCD involves higher energy expenditure, and could help explain why children with pDCD perform poorly on tasks requiring CRF.