Background: Clinical and research advancements in the field of fetal alcohol spectrum disorders (... more Background: Clinical and research advancements in the field of fetal alcohol spectrum disorders (FASD) require accurate and valid identification of FASD clinical subgroups. Objectives: A comprehensive neuropsychological battery, coupled with magnetic resonance imaging, (MRI), MR spectroscopy (MRS), and functional MRI (fMRI) were administered to children with fetal alcohol spectrum disorders (FASD) to determine if global and/or focal abnormalities could be identified across the spectrum, and distinguish diagnostic subclassifications within the spectrum. The neuropsychological outcomes of the comprehensive neuroimaging study are presented here. Methods: The study groups included: 1) FAS/Partial FAS; 2) Static Encephalopathy/Alcohol Exposed (SE/AE); 3) Neurobehavioral Disorder/Alcohol Exposed (ND/AE) as diagnosed by an interdisciplinary team using the FASD 4-Digit Code; and 4) healthy peers with no prenatal alcohol. A standardized neuropsychological battery was administered to each child and their primary caregiver by a psychologist. Results: Use of the 4-Digit Code produced three clinically and statistically distinct FASD clinical subgroups. The three subgroups (ND/AE, SE/AE and FAS/PFAS) reflected a linear continuum of increasing neuropsychological impairment and physical abnormality, representing the full continuum of FASD. Behavioral and psychiatric disorders were comparably prevalent across the three FASD groups, and significantly more prevalent than among the Controls. All three FASD subgroups had comparably high levels of prenatal alcohol exposure. Conclusions: Although ND/AE, SE/AE, and FAS/PFAS are distinct FASD subgroups, these groups are not distinguishable solely by their neuropsychological profiles. While all children within a group shared the same magnitude of neuropsychological impairment, the patterns of impairment showed considerable individual variability. MRI, MRS and fMRI further distinguished these FASD subgroups.
Despite the anecdotal evidence of social difficulties in children with Fetal Alcohol Spectrum Dis... more Despite the anecdotal evidence of social difficulties in children with Fetal Alcohol Spectrum Disorders (FASD), and the risk for secondary disabilities as a result of these social difficulties, very little research has examined social-emotional functioning in children with FASD. The majority of the research conducted thus far has relied on parent and teacher reports to document social impairments. These parent and teacher reports provide a broad measure of social functioning but are unable to elucidate the specific aspects of social functioning that this group of children might find difficult. As a result, it has been very difficult to develop effective social interventions for children with FASD because it is unclear what aspects of social functioning should be targeted. The current study aimed to examine emotion recognition abilities in children with FASD, as recognition of emotions is an important precursor for appropriate social interaction. The study included 22 participants with diagnosed FASD (ages 8-14), with age-and gendermatched typically developing controls. Participants were assessed using computerized measures of emotion recognition from three nonlinguistic modalities: facial expressions (static and dynamic, child and adult faces), emotional tone of voice (child and adult voices), and body positioning and movement (postures and point-light walkers). In addition, participants completed a task assessing emotion recognition in real-life scenarios. Finally, caregivers completed measures of behavioural functioning, adaptive functioning, FASD symptomatology, and a demographics questionnaire. Overall, findings suggest that children with FASD do have more difficulties than age-matched I would like to give my deepest thanks to my supervisor, Dr. Kimberly Kerns, for the years of mentorship, support, and guidance she provided as I navigated through graduate school. She helped me to do my best work on this project and others previously, and she continued to support me even when my life threw some curves into the journey. I am grateful for her faith in my abilities and her encouragement to help me reach my goals. I have also valued the relationship we have developed over the years: long chats about research, systems issues, and how to help kids reach their fullest potential. I hope that we will continue to collaborate and work together in the future.
Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder ... more Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder (ADHD) is characterized by the impact of abnormal reward prediction error signals carried by the midbrain dopamine system on frontal brain areas that implement cognitive control. To investigate this issue, we recorded the event-related brain potential (ERP) from typical children and children with ADHD as they navigated a "virtual maze" to find monetary rewards, and physically gave them their accumulated rewards halfway through the task and at the end of the experiment. We found that the amplitude of a rewardrelated ERP component decreased somewhat for typical children after they received their first payment, but increased for children with ADHD following the payment. This result indicates that children with ADHD are unusually sensitive to the salience of reward and suggests that such sensitivity may be mediated in part by the midbrain dopamine system.
Neuropsychiatry Neuropsychology and Behavioral Neurology, 1989
ABSTRACT The investigation and development of self-report measures of cognitive ability have focu... more ABSTRACT The investigation and development of self-report measures of cognitive ability have focused primarily on memory functions. We report on the development and validation of a questionnaire of visuoperceptual ability. A 45-item questionnaire was developed on a rational basis to assess self-ratings of visual perceptual and spatial ability. The questionnaire was administered to a sample of 68 neurologically normal adults aged 20-75 years. Reliability (internal and 6 month retest) for the questionnaire was satisfactory. Validity was established by relating questionnaire responses to objective test performance on measures of visual-perceptual functioning and nonvisual perceptual functioning. These findings indicate that it is possible to assess reliably and accurately the self-report ratings of visuoperceptual ability. Similarities and differences of these findings and those reported for self-report measures of memory ability are discussed. (C) Lippincott-Raven Publishers.
Objective: Planning is an important executive function (EF) skill that is fundamental to the capa... more Objective: Planning is an important executive function (EF) skill that is fundamental to the capacity to achieve everyday goals that require a series of intermediate steps. This study examined the effect of preterm birth on planning skills in early and middle childhood using Tower problems that made different cognitive workload demands. Method: We administered a novel touchscreen Tower of Hanoi task (Monkey Tree Task; MTT) in three age cohorts (3, 6, and 9 years) to 485 children born between 2000 and 2010 (105 extremely low birth weight [ELBW], 248 late preterm [LP], and 132 term-born [Term]). Results: Children born with ELBW completed significantly fewer Tower problems with higher cognitive demands than children born at Term or LP. Likewise, Term-and LP-born children completed more Tower problems than children born with ELBW. In the youngest cohort, Term-born children solved Tower problems more efficiently than either preterm group, and LP-born children solved problems more efficiently than those born with ELBW. However, there were no group differences in efficiency in the older age cohorts. Significant correlations between our MTT measures and performance on other EF tasks were found. Conclusions: The MTT captured significant performance differences in planning skills between children born term vs. preterm. This study provides important information on the impact that cognitive workload, as a function of Tower problem complexity, has on planning skills in preterm children. This study adds to a growing body of research that distinguishes LP birth as having subtle, but distinguishable, adverse neuropsychological outcomes at earlier ages.
Impairments in memory and new learning secondary to neurological illness or injury pose significa... more Impairments in memory and new learning secondary to neurological illness or injury pose significant problems for school age children. This paper describes the development and implementation of compensatory memory aids for an adolescent girl who demonstrated significant memory impairment following irradiation for an intracranial tumour. Strategies for integrating the system with the student's academic programme and school-related activities, and involvement of school personnel are emphasized, as is a theoretically and behaviourally based training programme.
Journal of Clinical and Experimental Neuropsychology, Aug 1, 2005
We present a new measure of nonverbal working memory for children, entitled the Children&... more We present a new measure of nonverbal working memory for children, entitled the Children's Size-Ordering Task (CSOT). Two separate studies were conducted to test the utility of and partially validate this measure. Three specific hypotheses were investigated, namely that: (1) CSOT performance would correlate with age; (2) the CSOT would correlate with established measures of working memory; and (3) children with ADHD would exhibit weaker performance on the CSOT relative to typically developing community control children. Participants across both studies included 50 children with ADHD and 50 control children matched by age and gender. Collectively, the results of both studies supported all three hypotheses. These findings lend support to the CSOT as a valid and effective measure of nonverbal working memory.
Prospective memory, defined as the ability to follow through on intended behavior, is believed to... more Prospective memory, defined as the ability to follow through on intended behavior, is believed to be subserved by a number of neuroanatomical substrates, but particularly dependent, at least in part, on the frontal lobes. Children with Attention-Deficit Hyperactivity Disorder (ADHD) traditionally have difficulty on tasks dependent on frontal lobe structures. The present study attempted to determine whether children with ADHD are impaired in prospective memory function. Two studies are described that use a new measure of time-based prospective memory, the CyberCruiser (Kerns, 2000), to compare children with ADHD to a control group consisting of participants who were matched in respect to age, gender, and IQ. The results document prospective memory deficits in ADHD. Prospective memory performance correlated significantly with clinical measures of ADHD as assessed by the Conners' Parent Rating Scale (Conners, 1990) Hyperactivity Index, but was unrelated to intellectual ability. Though psychometric measures of attention correlated with prospective memory performance, they did not account for the differences in prospective memory that were observed between the ADHD and control groups.
The literature on children with attention deficit/hyperactivity disorder, combined type (ADHD-C),... more The literature on children with attention deficit/hyperactivity disorder, combined type (ADHD-C), is currently inconclusive as to the nature of deficits in two forms of cognitive control-interference control and response selection (Nigg, 2006). This paper examined the performance of children with ADHD-C on interference control and response selection conflict tasks that required both speed and accuracy. The data was analyzed utilizing a new efficiency method to more effectively analyze overall responses. Both interference control and response selection conditions were combined within tasks allowing for a closer comparison of how children with ADHD-C perform on these specific types of cognitive control. Computerized tasks were administered to 62 boys, ages 7 to 12 (31 controls, 31 ADHD-C). Results revealed deficits in efficient performance for children with ADHD-C on interference control tasks and response selection tasks hypothesized to involve high cognitive control demand. These results highlight the utility of analyzing efficiency data to identify deficits in performance for children with ADHD-C and to foster an increased understanding of cognitive control functioning in this clinical population.
A multifactorial diagnostic assessment battery was evaluated using data obtained from 105 reading... more A multifactorial diagnostic assessment battery was evaluated using data obtained from 105 reading-disabled children and their matched controls (total N = 210). A stepwise discriminant function analysis selected five nonreading measures from among 16 as the best diagnostic predictors of reading disability. These measures included WISC-R Information and Digit Span, self-reported family histories of reading problems, and tests of symbol-processing speed and letter fluency.
Intra-individual variability (IIV) is defined as systematic within person variation in performanc... more Intra-individual variability (IIV) is defined as systematic within person variation in performance either across testing occasions (e.g., test/re-test performance on the same task) or within an occasion (e.g., variations in performance on multiple trials of a single task). Higher levels of IIV)) have been noted as a characteristic of neurodevelopmental disorders such as Attention Deficit/ Hyperactivity Disorder (Geurts et al., 2008), but IIV is yet to be investigated in Fetal Alcohol Spectrum Disorder (FASD). FASD is a term used to describe several conditions resulting from prenatal exposure to alcohol. As part of a comprehensive neuropsychological battery, four study groups (1. fetal alcohol syndrome ⁄ partial fetal alcohol syndrome; 2. static encephalopathy ⁄ alcohol exposed; 3. neurobehavioral disorder ⁄ alcohol exposed as diagnosed using the University of Washington FASD 4-Digit Code; and 4. healthy age-matched children with no prenatal alcohol exposure) were administered measures of motor response and inhibitory control, attention, and adaptive behavior. Results indicated increased levels of IIV in those with FASD compared to controls. IIV was found to uniquely contribute to predicting adaptive behavior above and beyond attention, while attention partially mediated the relationship between IIV and adaptive behavior. This is the first study to our knowledge to show the presence of increased IIV in children with FASD. It additionally provides evidence that IIV measures some inherent variability in performance independent of poor attention in children with FASD.
Motor behavior is not an isolated process but instead depends upon input from the visual, proprio... more Motor behavior is not an isolated process but instead depends upon input from the visual, proprioceptive, and vestibular systems. Children with Autism Spectrum Disorder (ASD) rely heavily upon visual cues for balance in static environments (Molloy, Dietrich, & Bhattacharya, 2003). The purpose of the present study was to determine whether visual sensitivity to dynamic cues was related to motor abilities in youth with AS. The accurate and timely visual analysis of movement is fundamentally important for the production and control of motor activity. Several studies have been published suggesting that children with ASD are compromised in their sensitivity to coherent visual motion (
Barkley (1997a) proposed that the central deficit in Attention Deficit Hyperactivity Disorder (AD... more Barkley (1997a) proposed that the central deficit in Attention Deficit Hyperactivity Disorder (ADHD) is in behavioral inhibition, resulting in deficits both in working memory and sense of time. To test this theory, 21 children with ADHD and a matched sample (ages 6-13) completed a variety of tasks that measured behavioral inhibition, working memory, attention, and time reproduction. Children with ADHD performed significantly below controls on measures of inhibition, attention, and time reproduction. They did not differ significantly from controls, however, on tasks of working memory. In addition, performance on the working memory tasks was not correlated with the time reproduction task. We discuss the relevance of these results in the context of current theories of ADHD.
Journal of The International Neuropsychological Society, 2000
Prospective memory can be defined as the timely execution of a previously formed intention, and i... more Prospective memory can be defined as the timely execution of a previously formed intention, and is critical in daily life because of its inherent involvement in goal-directed behavior. Cognitive systems involved in prospective memory have been hypothesized as involving the frontal cortex, and in adults, associated with working memory and executive functions. This study introduces a new computerized measure of prospective memory designed for children. In this study prospective memory is examined in a driving game task called the CyberCruiser. In a sample of 80 children ages 6–12 years, variables from this task demonstrated a significant age effect and were significantly correlated with other well known measures of executive function, even after controlling for chronological age. Performance on this task also demonstrated the anticipated pattern of strategic monitoring that has been demonstrated in other studies of prospective memory. (JINS, 2000, 6, 62–70.)
Journal of Autism and Developmental Disorders, Aug 8, 2006
Parents of children with autism frequently turn to the service delivery system to access supports... more Parents of children with autism frequently turn to the service delivery system to access supports designed to help adapt to the challenges of having a child with a lifelong impairment. Although studies have suggested various supports and coping strategies that are effective for adapting, few studies have examined parents' own perceptions of needs, and whether parents felt their needs were being met. In the present study the Family Needs Questionnaire (FNQ; Waaland et al., 1993) was modified to address needs for children with developmental disorders. A sample of fifty-six parents of children with autism and a comparison group of thirty-two parents of children with Down syndrome completed the FNQ. The groups did not differ significantly on the number of important needs reported nor the number of important needs being met. However, the two groups differed in the types of supports they most frequently endorsed as Important or Unmet.
Objective: The current study investigated executive function (EF) in young children with and with... more Objective: The current study investigated executive function (EF) in young children with and without autism spectrum disorder (ASD) using multiple methods of assessment. Method: Young children (M = 63.2 months) with and without ASD, matched on age, IQ, and maternal education, were assessed on computerized measures of working memory, inhibition, flexibility, and planning. Parents completed a behavior rating scale assessing children's EF within everyday contexts. Results: There were no significant group differences on working memory, inhibition, flexibility, or planning. The mean difference on one aspect of the planning task (number of correct trials), however, approached significance and showed a medium to large effect size. There was also a significant difference between groups on the EF behavior rating scale, indicating that participants with ASD demonstrated greater executive dysfunction, as indexed by parent report. Conclusions: The results suggest that in young children with ASD, EF difficulties may only become apparent when situational demands require coordinating multiple abilities, as assessed with scales indexing children's abilities to manage their day-today EF-related behavior. We suggest that multiple methods are needed to achieve a comprehensive and valid EF assessment in young children with ASD. The increasing demand for early intervention for children with autism spectrum disorder (ASD) has raised the need for developmentally sensitive assessment tools. The primary purpose of the assessments is to identify, and subsequently target, key domains of functioning that have the greatest overall impact on the child's daily life. Executive function (EF) may be an ideal target for early intervention, broadly referring to higher level cognitive control skills that allow one to evaluate a situation and to determine and successfully carry out an appropriate course of action.
ABSTRACT The Internet has become a widespread and important tool for sharing information througho... more ABSTRACT The Internet has become a widespread and important tool for sharing information throughout the world. Neuropsychologists are now able to communicate with colleagues, conduct literature searches, obtain articles and locate up-to-date clinical and research findings through this medium. This article provides some basic information about this technology and includes a list of over 150 sites on the World Wide Web of substantial interest to neuropsychologists.
This study examined the test-retest reliability of executive function tasks in preschool children... more This study examined the test-retest reliability of executive function tasks in preschool children. Measures of working memory, response inhibition, attentional flexibility, and planning were administered to thirty three preschool children between the ages of 36 and 72 months (M = 54.75 months) on two testing occasions approximately three weeks apart (M interval = 21.64 days). Working memory tasks showed higher test-retest reliability than measures of response inhibition. There were significant practice effects on three measures of complex working memory. Implications of these findings for the assessment of executive function in preschool children are discussed.
Background: Clinical and research advancements in the field of fetal alcohol spectrum disorders (... more Background: Clinical and research advancements in the field of fetal alcohol spectrum disorders (FASD) require accurate and valid identification of FASD clinical subgroups. Objectives: A comprehensive neuropsychological battery, coupled with magnetic resonance imaging, (MRI), MR spectroscopy (MRS), and functional MRI (fMRI) were administered to children with fetal alcohol spectrum disorders (FASD) to determine if global and/or focal abnormalities could be identified across the spectrum, and distinguish diagnostic subclassifications within the spectrum. The neuropsychological outcomes of the comprehensive neuroimaging study are presented here. Methods: The study groups included: 1) FAS/Partial FAS; 2) Static Encephalopathy/Alcohol Exposed (SE/AE); 3) Neurobehavioral Disorder/Alcohol Exposed (ND/AE) as diagnosed by an interdisciplinary team using the FASD 4-Digit Code; and 4) healthy peers with no prenatal alcohol. A standardized neuropsychological battery was administered to each child and their primary caregiver by a psychologist. Results: Use of the 4-Digit Code produced three clinically and statistically distinct FASD clinical subgroups. The three subgroups (ND/AE, SE/AE and FAS/PFAS) reflected a linear continuum of increasing neuropsychological impairment and physical abnormality, representing the full continuum of FASD. Behavioral and psychiatric disorders were comparably prevalent across the three FASD groups, and significantly more prevalent than among the Controls. All three FASD subgroups had comparably high levels of prenatal alcohol exposure. Conclusions: Although ND/AE, SE/AE, and FAS/PFAS are distinct FASD subgroups, these groups are not distinguishable solely by their neuropsychological profiles. While all children within a group shared the same magnitude of neuropsychological impairment, the patterns of impairment showed considerable individual variability. MRI, MRS and fMRI further distinguished these FASD subgroups.
Despite the anecdotal evidence of social difficulties in children with Fetal Alcohol Spectrum Dis... more Despite the anecdotal evidence of social difficulties in children with Fetal Alcohol Spectrum Disorders (FASD), and the risk for secondary disabilities as a result of these social difficulties, very little research has examined social-emotional functioning in children with FASD. The majority of the research conducted thus far has relied on parent and teacher reports to document social impairments. These parent and teacher reports provide a broad measure of social functioning but are unable to elucidate the specific aspects of social functioning that this group of children might find difficult. As a result, it has been very difficult to develop effective social interventions for children with FASD because it is unclear what aspects of social functioning should be targeted. The current study aimed to examine emotion recognition abilities in children with FASD, as recognition of emotions is an important precursor for appropriate social interaction. The study included 22 participants with diagnosed FASD (ages 8-14), with age-and gendermatched typically developing controls. Participants were assessed using computerized measures of emotion recognition from three nonlinguistic modalities: facial expressions (static and dynamic, child and adult faces), emotional tone of voice (child and adult voices), and body positioning and movement (postures and point-light walkers). In addition, participants completed a task assessing emotion recognition in real-life scenarios. Finally, caregivers completed measures of behavioural functioning, adaptive functioning, FASD symptomatology, and a demographics questionnaire. Overall, findings suggest that children with FASD do have more difficulties than age-matched I would like to give my deepest thanks to my supervisor, Dr. Kimberly Kerns, for the years of mentorship, support, and guidance she provided as I navigated through graduate school. She helped me to do my best work on this project and others previously, and she continued to support me even when my life threw some curves into the journey. I am grateful for her faith in my abilities and her encouragement to help me reach my goals. I have also valued the relationship we have developed over the years: long chats about research, systems issues, and how to help kids reach their fullest potential. I hope that we will continue to collaborate and work together in the future.
Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder ... more Behavioral and neurophysiological evidence suggest that attention-deficit hyperactivity disorder (ADHD) is characterized by the impact of abnormal reward prediction error signals carried by the midbrain dopamine system on frontal brain areas that implement cognitive control. To investigate this issue, we recorded the event-related brain potential (ERP) from typical children and children with ADHD as they navigated a "virtual maze" to find monetary rewards, and physically gave them their accumulated rewards halfway through the task and at the end of the experiment. We found that the amplitude of a rewardrelated ERP component decreased somewhat for typical children after they received their first payment, but increased for children with ADHD following the payment. This result indicates that children with ADHD are unusually sensitive to the salience of reward and suggests that such sensitivity may be mediated in part by the midbrain dopamine system.
Neuropsychiatry Neuropsychology and Behavioral Neurology, 1989
ABSTRACT The investigation and development of self-report measures of cognitive ability have focu... more ABSTRACT The investigation and development of self-report measures of cognitive ability have focused primarily on memory functions. We report on the development and validation of a questionnaire of visuoperceptual ability. A 45-item questionnaire was developed on a rational basis to assess self-ratings of visual perceptual and spatial ability. The questionnaire was administered to a sample of 68 neurologically normal adults aged 20-75 years. Reliability (internal and 6 month retest) for the questionnaire was satisfactory. Validity was established by relating questionnaire responses to objective test performance on measures of visual-perceptual functioning and nonvisual perceptual functioning. These findings indicate that it is possible to assess reliably and accurately the self-report ratings of visuoperceptual ability. Similarities and differences of these findings and those reported for self-report measures of memory ability are discussed. (C) Lippincott-Raven Publishers.
Objective: Planning is an important executive function (EF) skill that is fundamental to the capa... more Objective: Planning is an important executive function (EF) skill that is fundamental to the capacity to achieve everyday goals that require a series of intermediate steps. This study examined the effect of preterm birth on planning skills in early and middle childhood using Tower problems that made different cognitive workload demands. Method: We administered a novel touchscreen Tower of Hanoi task (Monkey Tree Task; MTT) in three age cohorts (3, 6, and 9 years) to 485 children born between 2000 and 2010 (105 extremely low birth weight [ELBW], 248 late preterm [LP], and 132 term-born [Term]). Results: Children born with ELBW completed significantly fewer Tower problems with higher cognitive demands than children born at Term or LP. Likewise, Term-and LP-born children completed more Tower problems than children born with ELBW. In the youngest cohort, Term-born children solved Tower problems more efficiently than either preterm group, and LP-born children solved problems more efficiently than those born with ELBW. However, there were no group differences in efficiency in the older age cohorts. Significant correlations between our MTT measures and performance on other EF tasks were found. Conclusions: The MTT captured significant performance differences in planning skills between children born term vs. preterm. This study provides important information on the impact that cognitive workload, as a function of Tower problem complexity, has on planning skills in preterm children. This study adds to a growing body of research that distinguishes LP birth as having subtle, but distinguishable, adverse neuropsychological outcomes at earlier ages.
Impairments in memory and new learning secondary to neurological illness or injury pose significa... more Impairments in memory and new learning secondary to neurological illness or injury pose significant problems for school age children. This paper describes the development and implementation of compensatory memory aids for an adolescent girl who demonstrated significant memory impairment following irradiation for an intracranial tumour. Strategies for integrating the system with the student's academic programme and school-related activities, and involvement of school personnel are emphasized, as is a theoretically and behaviourally based training programme.
Journal of Clinical and Experimental Neuropsychology, Aug 1, 2005
We present a new measure of nonverbal working memory for children, entitled the Children&... more We present a new measure of nonverbal working memory for children, entitled the Children's Size-Ordering Task (CSOT). Two separate studies were conducted to test the utility of and partially validate this measure. Three specific hypotheses were investigated, namely that: (1) CSOT performance would correlate with age; (2) the CSOT would correlate with established measures of working memory; and (3) children with ADHD would exhibit weaker performance on the CSOT relative to typically developing community control children. Participants across both studies included 50 children with ADHD and 50 control children matched by age and gender. Collectively, the results of both studies supported all three hypotheses. These findings lend support to the CSOT as a valid and effective measure of nonverbal working memory.
Prospective memory, defined as the ability to follow through on intended behavior, is believed to... more Prospective memory, defined as the ability to follow through on intended behavior, is believed to be subserved by a number of neuroanatomical substrates, but particularly dependent, at least in part, on the frontal lobes. Children with Attention-Deficit Hyperactivity Disorder (ADHD) traditionally have difficulty on tasks dependent on frontal lobe structures. The present study attempted to determine whether children with ADHD are impaired in prospective memory function. Two studies are described that use a new measure of time-based prospective memory, the CyberCruiser (Kerns, 2000), to compare children with ADHD to a control group consisting of participants who were matched in respect to age, gender, and IQ. The results document prospective memory deficits in ADHD. Prospective memory performance correlated significantly with clinical measures of ADHD as assessed by the Conners' Parent Rating Scale (Conners, 1990) Hyperactivity Index, but was unrelated to intellectual ability. Though psychometric measures of attention correlated with prospective memory performance, they did not account for the differences in prospective memory that were observed between the ADHD and control groups.
The literature on children with attention deficit/hyperactivity disorder, combined type (ADHD-C),... more The literature on children with attention deficit/hyperactivity disorder, combined type (ADHD-C), is currently inconclusive as to the nature of deficits in two forms of cognitive control-interference control and response selection (Nigg, 2006). This paper examined the performance of children with ADHD-C on interference control and response selection conflict tasks that required both speed and accuracy. The data was analyzed utilizing a new efficiency method to more effectively analyze overall responses. Both interference control and response selection conditions were combined within tasks allowing for a closer comparison of how children with ADHD-C perform on these specific types of cognitive control. Computerized tasks were administered to 62 boys, ages 7 to 12 (31 controls, 31 ADHD-C). Results revealed deficits in efficient performance for children with ADHD-C on interference control tasks and response selection tasks hypothesized to involve high cognitive control demand. These results highlight the utility of analyzing efficiency data to identify deficits in performance for children with ADHD-C and to foster an increased understanding of cognitive control functioning in this clinical population.
A multifactorial diagnostic assessment battery was evaluated using data obtained from 105 reading... more A multifactorial diagnostic assessment battery was evaluated using data obtained from 105 reading-disabled children and their matched controls (total N = 210). A stepwise discriminant function analysis selected five nonreading measures from among 16 as the best diagnostic predictors of reading disability. These measures included WISC-R Information and Digit Span, self-reported family histories of reading problems, and tests of symbol-processing speed and letter fluency.
Intra-individual variability (IIV) is defined as systematic within person variation in performanc... more Intra-individual variability (IIV) is defined as systematic within person variation in performance either across testing occasions (e.g., test/re-test performance on the same task) or within an occasion (e.g., variations in performance on multiple trials of a single task). Higher levels of IIV)) have been noted as a characteristic of neurodevelopmental disorders such as Attention Deficit/ Hyperactivity Disorder (Geurts et al., 2008), but IIV is yet to be investigated in Fetal Alcohol Spectrum Disorder (FASD). FASD is a term used to describe several conditions resulting from prenatal exposure to alcohol. As part of a comprehensive neuropsychological battery, four study groups (1. fetal alcohol syndrome ⁄ partial fetal alcohol syndrome; 2. static encephalopathy ⁄ alcohol exposed; 3. neurobehavioral disorder ⁄ alcohol exposed as diagnosed using the University of Washington FASD 4-Digit Code; and 4. healthy age-matched children with no prenatal alcohol exposure) were administered measures of motor response and inhibitory control, attention, and adaptive behavior. Results indicated increased levels of IIV in those with FASD compared to controls. IIV was found to uniquely contribute to predicting adaptive behavior above and beyond attention, while attention partially mediated the relationship between IIV and adaptive behavior. This is the first study to our knowledge to show the presence of increased IIV in children with FASD. It additionally provides evidence that IIV measures some inherent variability in performance independent of poor attention in children with FASD.
Motor behavior is not an isolated process but instead depends upon input from the visual, proprio... more Motor behavior is not an isolated process but instead depends upon input from the visual, proprioceptive, and vestibular systems. Children with Autism Spectrum Disorder (ASD) rely heavily upon visual cues for balance in static environments (Molloy, Dietrich, & Bhattacharya, 2003). The purpose of the present study was to determine whether visual sensitivity to dynamic cues was related to motor abilities in youth with AS. The accurate and timely visual analysis of movement is fundamentally important for the production and control of motor activity. Several studies have been published suggesting that children with ASD are compromised in their sensitivity to coherent visual motion (
Barkley (1997a) proposed that the central deficit in Attention Deficit Hyperactivity Disorder (AD... more Barkley (1997a) proposed that the central deficit in Attention Deficit Hyperactivity Disorder (ADHD) is in behavioral inhibition, resulting in deficits both in working memory and sense of time. To test this theory, 21 children with ADHD and a matched sample (ages 6-13) completed a variety of tasks that measured behavioral inhibition, working memory, attention, and time reproduction. Children with ADHD performed significantly below controls on measures of inhibition, attention, and time reproduction. They did not differ significantly from controls, however, on tasks of working memory. In addition, performance on the working memory tasks was not correlated with the time reproduction task. We discuss the relevance of these results in the context of current theories of ADHD.
Journal of The International Neuropsychological Society, 2000
Prospective memory can be defined as the timely execution of a previously formed intention, and i... more Prospective memory can be defined as the timely execution of a previously formed intention, and is critical in daily life because of its inherent involvement in goal-directed behavior. Cognitive systems involved in prospective memory have been hypothesized as involving the frontal cortex, and in adults, associated with working memory and executive functions. This study introduces a new computerized measure of prospective memory designed for children. In this study prospective memory is examined in a driving game task called the CyberCruiser. In a sample of 80 children ages 6–12 years, variables from this task demonstrated a significant age effect and were significantly correlated with other well known measures of executive function, even after controlling for chronological age. Performance on this task also demonstrated the anticipated pattern of strategic monitoring that has been demonstrated in other studies of prospective memory. (JINS, 2000, 6, 62–70.)
Journal of Autism and Developmental Disorders, Aug 8, 2006
Parents of children with autism frequently turn to the service delivery system to access supports... more Parents of children with autism frequently turn to the service delivery system to access supports designed to help adapt to the challenges of having a child with a lifelong impairment. Although studies have suggested various supports and coping strategies that are effective for adapting, few studies have examined parents' own perceptions of needs, and whether parents felt their needs were being met. In the present study the Family Needs Questionnaire (FNQ; Waaland et al., 1993) was modified to address needs for children with developmental disorders. A sample of fifty-six parents of children with autism and a comparison group of thirty-two parents of children with Down syndrome completed the FNQ. The groups did not differ significantly on the number of important needs reported nor the number of important needs being met. However, the two groups differed in the types of supports they most frequently endorsed as Important or Unmet.
Objective: The current study investigated executive function (EF) in young children with and with... more Objective: The current study investigated executive function (EF) in young children with and without autism spectrum disorder (ASD) using multiple methods of assessment. Method: Young children (M = 63.2 months) with and without ASD, matched on age, IQ, and maternal education, were assessed on computerized measures of working memory, inhibition, flexibility, and planning. Parents completed a behavior rating scale assessing children's EF within everyday contexts. Results: There were no significant group differences on working memory, inhibition, flexibility, or planning. The mean difference on one aspect of the planning task (number of correct trials), however, approached significance and showed a medium to large effect size. There was also a significant difference between groups on the EF behavior rating scale, indicating that participants with ASD demonstrated greater executive dysfunction, as indexed by parent report. Conclusions: The results suggest that in young children with ASD, EF difficulties may only become apparent when situational demands require coordinating multiple abilities, as assessed with scales indexing children's abilities to manage their day-today EF-related behavior. We suggest that multiple methods are needed to achieve a comprehensive and valid EF assessment in young children with ASD. The increasing demand for early intervention for children with autism spectrum disorder (ASD) has raised the need for developmentally sensitive assessment tools. The primary purpose of the assessments is to identify, and subsequently target, key domains of functioning that have the greatest overall impact on the child's daily life. Executive function (EF) may be an ideal target for early intervention, broadly referring to higher level cognitive control skills that allow one to evaluate a situation and to determine and successfully carry out an appropriate course of action.
ABSTRACT The Internet has become a widespread and important tool for sharing information througho... more ABSTRACT The Internet has become a widespread and important tool for sharing information throughout the world. Neuropsychologists are now able to communicate with colleagues, conduct literature searches, obtain articles and locate up-to-date clinical and research findings through this medium. This article provides some basic information about this technology and includes a list of over 150 sites on the World Wide Web of substantial interest to neuropsychologists.
This study examined the test-retest reliability of executive function tasks in preschool children... more This study examined the test-retest reliability of executive function tasks in preschool children. Measures of working memory, response inhibition, attentional flexibility, and planning were administered to thirty three preschool children between the ages of 36 and 72 months (M = 54.75 months) on two testing occasions approximately three weeks apart (M interval = 21.64 days). Working memory tasks showed higher test-retest reliability than measures of response inhibition. There were significant practice effects on three measures of complex working memory. Implications of these findings for the assessment of executive function in preschool children are discussed.
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Papers by Kimberly Kerns