Browsing by Subject "Neuropsychology"
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Item A neuropsychological investigation of two subtypes of dyslexia in college students(Texas Tech University, 1984-08) Gelbort, Michael MayerNot availableItem Assessing Visuospatial Neglect in Children with Brain Injury(2014-05-28) Wahlberg, Andrea ChristineVisuospatial neglect (VSN), the failure to report, respond, or orient to novel or meaningful visual stimuli presented in a specific location, is a frequently occurring outcome following stroke. VSN can negatively impact the functions of daily life and is an important predictor for long term outcomes. The phenomenon is frequently studied in adult populations; however, the nature and incidence of VSN following childhood stroke is virtually unknown. Current research investigating the neuroanatomical correlates of VSN and hypothesized models of dysfunction all assume a fully mature brain and thus lack a developmental perspective. Similarly, current neuropsychological measures used to assess VSN are almost exclusively developed and normed with adult populations. While some individual adult tests have been modified for use with children, no standardized battery to assess VSN in young children currently exists. The present study investigated the reliability and validity of a five-task neuropsychological testing battery, the Pediatric Visuospatial Neglect Battery, developed at the Children?s Hospital of Philadelphia (CHOP) to assess VSN in young children ages 2-6 following stroke. Although there were some exceptions, the reliability estimates of task scores obtained from the present sample were generally low. With regard to criterion-related validity, sensitivity to detect brain injury was generally poor while specificity was high. Some of the low reliability and validity estimates were due to measurement problems of the calculated variables. These variables can be reexamined and likely improved in future studies. In other instances, modifications to the tasks are recommended. Specific recommendations for improving the five existing tasks are provided as well as suggestions for additional tasks that could potentially be added to the battery in future administrations. Although somewhat disappointing, low initial reliability and validity estimates are part and parcel to test development. This study represents an important first step in developing a standardized battery to detect VSN in children. With refinement and additional testing, the Pediatric Visuospatial Neglect Battery may soon become an excellent instrument for investigating the VSN phenomenon in children.Item Cerebellar tumor location as a predictor of neurocognitive functioning among survivors of pediatric brain tumors(2016-12) Mitchell Von Buttlar, Ashlee Beth; Allen, Greg, doctor of clinical psychology; Greenspahn, Emily SThe literature has clearly demonstrated that the cerebellum serves as a major processing center in the brain for many complex functional pathways ranging from attention and learning to emotions and affect. Research is now emphasizing the importance of connectivity between the cerebellum and other brain regions, and has begun highlighting the need to understand the impact of damage to distinct regions on functional pathways throughout the brain. One particular type of cerebellar damage, caused by posterior fossa tumors, has received substantial attention in the medical and neuropsychological literature in recent years. Tumors of the posterior fossa, which includes the cerebellum and brain stem structures, account for over 15% of brain tumors in children. Due to advances in treatment, survival rates have increased dramatically for individuals with posterior fossa tumors, leading to a greater need for long-term medical and psychosocial care. Treatments for these tumors, including chemotherapy and cranial radiation, are known to produce long-term deficits in a variety of neurocognitive domains. These deficits are referred to as “neurocognitive late effects,” and can be seen as impaired performance in the areas of attention, memory, executive functioning, visual-spatial processing, and processing speed. Neurocognitive late effects can be especially pronounced in patients with localized cranial radiation, as is common with malignant brain tumors. Research has clearly shown that different regions of the cerebellum uniquely contribute to various neurocognitive functions. Additionally, much research has assessed the neurocognitive implications of posterior fossa tumors in children. However, little work has examined the unique relationship between specific tumor locations within the cerebellum and later neurocognitive outcomes. The purpose of this document is to propose a study to determine whether the particular location of tumors in the cerebellum can predict neurocognitive functioning in the domains of attention and executive functioning in children with these tumors.Item The cerebellum and divided attention in autism spectrum disorders(2014-08) Hsu, Julie Yong; Allen, Greg, doctor of clinical psychologyDivided attention, or the ability to respond to more than one task simultaneously, is an important skill for navigating complex social, communicative, academic, and professional settings. The purpose of the current study was to understand the association between the volume of the posterior cerebellum and divided attention in individuals with autism spectrum disorders (ASDs) and control participants. It was hypothesized that the ASD group would have worse divided attention abilities and smaller posterior cerebellar volumes compared to the control group. Furthermore, reduced posterior cerebellar volume was expected to be associated with weaker divided attention abilities. Participants were young adult males with high-functioning autism spectrum disorders (n=15) and controls matched for age, handedness, and nonverbal IQ (n=19). Results showed partial support for worse divided attention performance in ASDs and for a positive association between posterior cerebellar volume and divided attention performance. There were no group differences in posterior cerebellar volume, and accounting for intracranial volume did not affect findings. Limitations of the current study and future directions are discussed.Item Changes in neuropsychological functioning in an aging population(Texas Tech University, 1979-12) Bak, Joseph SNot availableItem Child and parent experiences of neuropsychological assessment as a function of child-centered feedback(2010-08) Pilgrim, Shea McNeill; Tharinger, Deborah J.; Bunner, Melissa Renee, 1969-; Keith, Timothy; Cawthon, Stephanie; Sherry, Alissa; Nussbaum, NancyResearch has paid little attention to clients’ experience of the psychological assessment process, particularly in regard to the experiences of children and their parents. Advocates of collaborative assessment have long espoused the therapeutic benefits of providing feedback that can help clients better understand themselves and improve their lives (Finn & Tonsager, 1992; Fischer, 1970, 1985/1994). Finn, Tharinger, and colleagues (2007; 2009) have extended a semi-structured form of collaborative assessment, Therapeutic Assessment (TA), with children. One important aspect of their method, drawn from Fischer’s (1985/1994) example, is the creation of individualized fables that incorporate assessment findings into a child-friendly format. The fables are then shared with the child and parents as assessment feedback. This study evaluated whether receiving this type of individualized, developmentally appropriate feedback would affect how children and their parents report experiencing the assessment process. The assessment process, with the exception of child feedback, was standard for the setting. Participants were 32 children who underwent a neuropsychological evaluation at a private outpatient clinic, along with their parents. Multivariate and univariate statistics were used to test differences between two groups: an experimental group that received individualized fables as child-focused feedback and a control group. Children in the experimental group reported a greater sense of learning about themselves, a more positive relationship with their assessor, a greater sense of collaboration with the assessment process, and a sense that their parents learned more about them because of the assessment than did children in the control group. Parents in the experimental group reported a more positive relationship between their child and the assessor, a greater sense of collaboration with the assessment process, and higher satisfaction with clinic services compared to the control group. Limitations to the study, implications for assessment practice with children, and future directions for research are discussed.Item Dichotomizing spelling errors to examine language and executive function abilities in children at risk of reading failure(2011-08) Kayser, Kimberly Anne; Nussbaum, Nancy; Carlson, Cindy I., 1949-; Allen, Greg; Beretvas, Tasha; Lasater, LisaSubstantial evidence emphasizing the importance of linguistic systems in reading acquisition, as well as emerging literature identifying the contribution of executive function to linguistic-based difficulties, underscores the importance of clarifying the neurocognitive mechanisms affecting reading performance. Research demonstrating the interrelationship between reading and spelling, coupled with neurocognitive theories of spelling, suggests that analysis of children’s spelling attempts may capture more subtle differences in their understanding of how to decode text. This study aimed to determine the utility of applying a spelling error analysis system as a method for differentiating between reading difficulties resulting from executive dysfunction or language deficits in a sample of children at risk for reading failure. The present study examined the relationship between executive function, language, and spelling achievement in a sample of 82 children aged 6-15 years identified as having a reading deficit and/or diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). Hierarchical regression analyses indicated language-based skills, particularly word reading, and age significantly predicted the phonemic equivalency of misspellings. Tasks of executive functioning were not found to significantly contribute to performance on phonological spelling; however, analysis of group differences suggest that ADHD and Reading Deficit groups demonstrated unique cognitive profiles, including distinct performances on executive functioning tasks. Exploratory analyses also revealed that ADHD and Reading Deficit groups differed significantly in phonological spelling performance. Results from the current study provide evidence for the presence of two distinct underlying cognitive processes affecting spelling and, in effect, reading. Current findings have implications for the need to further examine characteristic deficits in language and executive functioning affecting children at risk for reading failure. Findings also provide support for the validity of further investigating the potential to infer differential diagnostic categories using a phonological spelling analysis. The use of an analysis of spelling errors as a diagnostic data source holds promise for a better understanding of reading failure and, ultimately, may contribute to more effective intervention practices.Item Effects of hypertension and diabetes mellitus on cognitive functioning: A profile analytic approach(Texas Tech University, 2009-08) Clark, Joy HumphreysResearch studies have demonstrated a relationship between several cardiovascular risk factors and decreased performance on cognitive tasks. In particular, recent research has suggested a strong effect of hypertension and diabetes mellitus on neuropsychological performance, particularly in certain cognitive domains, in both cognitively normal and demented individuals. Findings have been mixed, however, with some studies showing significant effects and others demonstrating none. Despite widely differing methodologies, all previous studies have had one thing in common: the examination of mean-group differences in performance on individual cognitive tests. The current study, conversely, investigated possible differences in neuropsychological profiles across several cognitive measures between cognitively normal individuals with and without hypertension and/or diabetes, as well as between individuals diagnosed with Alzheimer's disease with or without either condition. While effects of hypertension and diabetes on cognitive functioning were found in specific cognitive domains, current analyses did not find overall profile differences.Item fMRI Investigation of an Experimental Executive Function Measure: Comparison of the Texas Card Sorting Test to the Wisconsin Card Sorting Test in Healthy Adults(2006-12-20) Woolston, Dixie J.; Allen, GregAlthough executive functioning is one of the most studied constructs in neuropsychology, it remains one of the most elusive and enigmatic skill sets to measure and understand. The Wisconsin Card Sorting Test (WCST) is commonly used to assess executive functioning, though it has been criticized for its lengthy administration time and negative feedback component. The Texas Card Sorting Test (TCST) was developed as a problem-solving measure to be applied in linguistically diverse samples, and does not have the limitations of the WCST. The overall purpose of the present study was to validate the TCST as a measure of frontal and subcortical function, and to compare the TCST to the WCST. Twenty-five healthy volunteers underwent functional magnetic resonance imaging (fMRI) while performing computerized versions of the WCST and TCST. Significant activations during the TCST were observed in the prefrontal cortex (BA 6, 9, 44-47), the basal ganglia, bilateral parietal areas (BA 7&39), left cingulate gyrus (BA 24, 31,&32), right superior temporal areas (BA 41&22), left parahippocampal and middle temporal gyri, and right occipital lobe (BA 18&19). Compared to the WCST, the TCST showed increased activity bilaterally in the frontal lobe (BA 6&47), right frontal areas (BA 10&11), the caudate, right superior temporal lobe (BA 38, 41, 42), right temporal lobe (BA 22&34), and left occipital lobe (BA 19&31). Behaviorally, no significant correlations were seen between the WCST and TCST performance variables. This research supports the TCST as a measure of frontal-subcortical function. The TCST appears to be particularly sensitive to orbitofrontal/caudate circuitry as well as superior temporal areas, with greater activation overall observed in right cerebral areas. Given the lack of correlation on behavioral performance variables and the distinct differences in neural correlates, the TCST may assess cognitive processes that are different from the WCST. The TCST has promising potential as a clinical neuropsychological instrument.Item Herpes simplex-1 as an additive risk factor for cognitive decline in apolipoprotein E4 carriers(2015-08) Eagan, Danielle Erin; Haley, Andreana P.; Schnyer, David M; Maddox, Todd; Mumford, Jeanette; Sullivan, ChristopherThe identification of early, modifiable risk factors for cognitive decline presents the most promising opportunity for intervention. To date one of the most robustly replicated risk factors for the most common form of dementia, Alzheimer’s disease (AD), is the Apolipoprotein E4 (ApoE4) allele. Risk for sporadic and familial late onset AD increases nearly threefold for each E4 allele an individual carries. However some E4 carriers do not develop cognitive decline, and many non-E4 carriers do, highlighting the role of environmental variables in the progression to clinical symptoms. There is evidence that herpes simplex-1 (HSV-1), a common neurotropic viral infection with affinity for the same brain structures affected in AD, is an acquired risk factor that may compound the genetic risk associated with ApoE4. We examined the interaction between the ApoE4 allele and HSV-1 in cognitively normal middle-aged adults using neuropsychological testing and structural and functional neuroimaging. Neuropsychological assessments were used to determine cognitive differences between groups. Structural neuroimaging was used to measure group differences in bilateral hippocampal volumes, and cortical thickness in brain regions most likely to be affected by AD and HSV-1. Functional neuroimaging was used to examine differences in resting- state brain activity within the default mode network (DMN), a network known for alterations in functional connectivity during the progression from normal aging to AD. With regard to cognition we found that ApoE4 carriers performed significantly lower on tests of executive functioning when they were infected with HSV-1. HSV-1 infection alone also correlated with significantly lower full scale IQ (FSIQ). Within the structural domain we found that individuals with ApoE4 had significantly smaller bilateral hippocampal volumes compared to individuals without the virus, regardless of HSV-1 status. Within the functional domain we failed to find any group differences in functional connectivity within the DMN. Together these findings suggest that HSV-1 may contribute to cognitive changes linked to cognitive vulnerability, and that ApoE4 may contribute to structural brain vulnerability. Because these factors are identifiable prior to the onset of frank cognitive decline, antiviral intervention could be considered as a means of mitigating risk for cognitive decline.Item How Hot or Cool is It to Speak Two Languages: Executive Function Advantages in Bilingual Children(2012-10-19) Weber, Rachel ChristianeAccording to the 2009 U.S. Census Bureau, approximately 57 million individuals, ages five and older, living in the United States spoke a language other than English at home. There is a clear and growing number of bilingual individuals and English Language Learners (ELL) in the United States. With these growing numbers, especially within the school-aged population, it is crucial that a clear understanding exist regarding the development of children who are bilingual or learning English as their second language. There is evidence that bilingual children differ from their monolingual peers in the development of executive function (EF), and specifically demonstrate some advantages on EF tasks. This research has not been expanded to include the new conceptualization of EF as hot and cool. This study seeks to examine bilingual EF advantages in EF in light of this recent conceptualization. A second goal of this study is to identify other psychosocial variables that predict EF in children and, thus, might impact its development. The variables of interest include socioeconomic status (SES), economic stress, parenting practices (e.g., disciplinary practices and relational frustration), and cultural beliefs (e.g., individualism/collectivism). A sample of 67 bilingual and monolingual English speaking children and their parents/guardians participated in this study. Children completed 4 EF tasks and parents completed a battery which included measures of the psychosocial variables and the BRIEF Parent Form. A MANCOVA model was utilized to examine bilingual differences in EF. Multiple regression models were also used to test for significant predictors of hot and cool EF and general EF (as measured by the BRIEF GEC) among the psychosocial variables. No significant group differences were found in multivariate analyses. Significant predictors of specific EF measures and hot and cool total scores were identified, including economic stress, age, relational frustration, vertical individualism, and vertical collectivism. These are discussed in light of current literature and clinical applications.Item Left frontal lobe dysfunction in "Schizophrenic-like" college students(Texas Tech University, 1991-12) Weinstein-Richardson, LisaNot availableItem Left frontal neuropsychological functioning in paranoid and nonparanoid schizophrenics(Texas Tech University, 1983-12) Langell, Mary ElizabethNot availableItem Neurocognitive profiles in autism spectrum disorder(2014-05) Wagner, Amanda E.; Allen, Greg, doctor of clinical psychologyThe current research project examines the performance of a group of high functioning young adult males with autism spectrum disorders on standardized measures of neurocognitive functioning to determine whether distinct cognitive profiles of strengths and weaknesses emerge. Neuropsychological test data across various domains: general cognitive ability, visuospatial processing, verbal learning and memory, visual learning and memory, working memory, reasoning, cognitive flexibility, attention, receptive language, expressive language, social and emotional processing, and fine motor skills was examined. Data were analyzed using cluster analysis to assess for the presence and nature of unique clusters/subgroups based on neuropsychological test performance. Three unique clusters were derived from the analyses. This study highlights the well-documented heterogeneity across the spectrum of autism and suggests a method for parsing a heterogeneous sample of ASD subjects into smaller and more meaningful homogeneous groups using standardized neuropsychological assessments.Item Processing speed and executive function in pediatric acute lymphoblastic leukemia survivors(2012-12) Garrison, Daniel Alexander; Carlson, Cindy I., 1949-; Robillard, Rachel WestThis study examined processing speed and executive function late effects in survivors of pediatric ALL (hereafter referred to as Survivors). Late effects are long-term, treatment-related health problems associated with the neurotoxic side-effect of cancer treatment on brain development. Processing speed —mental and motor speed with which a person can solve nonverbal problems — was estimated via an composite of processing speed attained from several measures of processing speed. Executive function — a collection of processes orchestrated in the performance of purposeful, goal-directed behavior — was measured using the Parent and Teacher forms of the Behavior Rating Inventory of Executive Function (BRIEF). This study also explored the effect of previously identified risk factors for processing speed and executive function late effects. Finally, executive function late effects were further explored via the use of performance-based measures, including the Tower and Trail Making (Condition 4) tests of the Delis-Kaplan Executive Function System (D-KEFS). Hypotheses included (1) Survivors would demonstrate significantly poorer processing speed; (2) late effects risk factor variables (i.e., greater elapsed time since completion of treatment, lower age at diagnosis, and higher intensity of treatment) would predict poorer processing speed; (3) female gender would predict poorer processing speed; (4) parents and teachers would demonstrate both low interrater agreement (Hypothesis 4a) and differ significantly in the severity (Hypothesis 4b) of their ratings of Survivor executive function; (5) parent and teacher ratings of executive function would indicate significantly poorer Survivor metacognition (Hypothesis 5a), whereas Survivor behavioral regulation would not differ significantly (Hypothesis 5b); (6) risk factor variables would predict poorer Parent and Teacher ratings of Survivor metacognition; (7) female gender would predict poorer Parent and Teacher ratings of Survivor metacognition; (8) survivor processing speed and Parent and Teacher ratings of executive function would exhibit a positive relationship; and (9) poorer Survivor processing speed would predict poorer parent and teacher ratings of executive function. Results provided support for hypothesis 1 and 5a. Partial support was obtained for hypotheses 4a, 4b, and 7. Hypotheses 2, 3, 5b, 6, 8, and 9 were not supported.Item Reliability and practice effects on the Luria-Nebraska neuropsychological battery and the Revised Wechsler memory scale(Texas Tech University, 1983-05) Campbell, Brian RossNot availableItem Reliability and practice effects on the Luria-Nebraska neuropsychological battery and the Revised Wechsler memory scale(Texas Tech University, 1983-05) Campbell, Brian RossThis study was designed to examine the reliability of equivalent and parallel forms of two representative neuropsychological tests: the Revised Wechsler Memory Scale (RWMS) created by Elbert W. Russell (1975) and the Luria-Nebraska Neuropsychological Battery (LN) developed by Charles J. Golden and his colleagues (Golden, Hammeke, & Purisch, 1978; Golden, Purisch, & Hammeke, 1978, 1979; Lewis, Golden, Moses, Osmon, Purisch, & Hammeke, 1979; Osmon, Golden, Purisch, Hammeke, & Blume, 1979; Purisch, Golden, & Hammeke, 1978). Although studies have been conducted which explore the reliability of Golden's scoring procedure, the split-half reliability of the original form of the battery, and the test-retest reliabilities of the 14 clinical scales, no research has been conducted to cross-validate these results or to examine the reliability of using parallel forms. Information concerning the internal consistency of the Luria-Nebraska, as well as test reliability, standard error(s) of measurement, and practice effects are vitally important for clinicians interested in employing neuropsychological instruments on a repeated basis to evaluate a patient's process of recovery from brain damage. The examination of the reliability of parallel test forms is particularly valuable since this reliability procedure is "the most rigorous" test of the accuracy of an assessment device (Thorndike & Hagen, 1961, p. 178).Item Verbal learning ability after traumatic brain injury : roles of working memory and processing speed(2011-08) Ridley, Kristen Paige; Keith, Timothy, 1952-; Allen, Greg; Mercer, Walt; Robillard, Rachel; Schallert, DianeLearning and memory impairments are among the most common and enduring cognitive consequences of traumatic brain injury (TBI). Researchers have yet to reach a consensus with regard to the basic cognitive mechanism underlying new learning and memory disturbances after TBI. The purpose of the present study was to investigate the current views regarding the cognitive processes thought to explain impairments in verbal learning and memory subsequent to brain injury. Specifically, this study sought to examine the roles of the central executive component of working memory and processing speed in verbal learning ability following TBI. Latent variable structural equation modeling (SEM) was used to analyze the data of 70 post-acute care TBI patients between the ages of 16 and 65, who completed a full neuropsychological evaluation. Results indicated that verbal learning and memory difficulties following TBI were explained primarily in terms of the central executive aspects of working memory, after accounting for the relative contributions of processing speed in the model. The direct effect of processing speed on verbal learning and memory was not significant when working memory was taken into account in the model. Rather, the effects of processing speed on verbal learning ability were largely indirect through the central executive component of working memory. Results highlight the importance of both working memory and processing speed in supporting verbal learning and memory processes after TBI. Practical implications for targeting remediation efforts and directing approaches to memory rehabilitation are discussed in light of the study’s findings.Item Working memory late effects in survivors of pediatric acute lymphoblastic leukemia(2011-08) Winter, Amanda Lee; Robillard, Rachel West; Carlson, Cindy I., 1949-; Keith, Timothy; Allen, Greg; Mercer, WaltAcute Lymphoblastic Leukemia (ALL) is the most commonly diagnosed malignancy in children (Pui, 2000; Steen & Mirro, 2000; American Cancer Society, 2009; Westlake & Bertolone, 2002). Modern advances in cancer treatment, such as combination chemotherapy (Ettinger, Bond, & Sievers, 2002; Rodman & Reed, 2009), have increased survivorship of ALL to nearly 85% (Westlake & Bertolone, 2002). This new population of ALL survivors is displaying a unique profile of cognitive late effects that are a result of the treatment (e.g. chemotherapy) which while effective in eradicating the disease, has neurotoxic properties (American Cancer Society, 2009). Late effects have been discovered in a variety of cognitive skills, including academic achievement, visual-spatial skills, and processing speed, but the most commonly seen late effects are in the areas of attention and memory (e.g. Askins & Moore, 2008; Cullen, Derrickson, & Potter, 2002; Leigh, 2000). While working memory is a skill that depends on both attention and memory (Baddeley 2000) and is important in both academic performance and life skills (Dark & Benbow, 1991; Geary, Hoard, & Hamson, 1999), it is relatively unstudied in this population. The purpose of this study was to investigate working memory abilities in survivors of pediatric ALL. Working memory skills in this population were compared to both sample and population IQ. Comparisons of verbal and nonverbal working memory and male and female working memory skills were compared as well. First, working memory, as measured by a composite, was not found to be significantly impaired when compared to sample and population mean IQ. However, a single subtest, Digit Span Backward from the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV; Wechsler, 2003), when compared to IQ outside the composite, was found to be significantly below IQ for both the sample and population mean. Second, no gender differences were found for working memory abilities. Finally, there was no difference between nonverbal and verbal working memory performance. While the results were nonsignificant, verbal working memory was worse than nonverbal working memory, which was the opposite of the hypothesized pattern. Implications, recommendations, and limitations of this study are discussed in detail.