Neurodevelopmental Disorders

Brain Activation Profiles in Dyslexia: A MEG Study (Supported by 1R01HD038346-01A1), Andrew C. Papanicolaou, P.I.

An area in which MEG has proved exceptionally useful is for imaging children with developmental dyslexia. A specific profile of brain activation has been identified in our laboratory and replicated in many studies. Dyslexia is a specific disability in learning to decode print at the single word level and often persists into adulthood when early interventions are insufficient. Some children have unusual problems with reading and with associated skills such as spelling. It is understood that the problem is dissociated from general intelligence. One of the core problems faced by individuals with dyslexia is difficulty with grasping the sound structure of the language, a skill known as phonological awareness. There is now overwhelming evidence that phonological awareness is the core deficit in most forms of reading disability and has been shown to predict later reading achievement. This study used MEG to explore brain activity patterns of dyslexic children as compared to that of normal readers. In the context of these studies, we also collected data from dyslexic children before and after participating in intensive eight-week-long intervention programs that emphasize normalization of brain activity following successful intensive training in phonological awareness skills.

Cognitive Instructional and Neuroimaging Factors In Math (Supported by 1R01 HD046261), Andrew C. Papanicolaou, P.I.

The purposes of this study were two fold: First, to address the question of whether different learning disabilities in math are associated with profiles of aberrant brain activation. Second, whether significant changes in these profiles take place following successful instructional intervention. This project was modeled after our previous successful attempts to identify a dyslexia-specific brain activation profile using MSI and evaluate changes in it as a function of a successful instructional intervention. Specifically, used MSI in an attempt to first, identify aberrant activation patterns underlying different types of math difficulties, and second, to determine whether successful intervention that results in improved performance in arithmetic tasks is reflected in normalization or other changes of the corresponding brain activity patterns. In the context of the first aim, we sought to determine whether children with math difficulties present aberrant activation patterns only during explicit arithmetic tasks (subtraction, addition) or also during tasks that engage concepts of numerosity removed from specific numbers. Finally, in the context of the second aim, we sought to establish whether there are clear neurophysiological effects (e.g. normalization of activation patterns) contingent on successful remedial math instruction.

Spina Bifida: Cognitive and Neurobiological Variability (Supported by P01 HD35946), Andrew C. Papanicolaou, P.I.

The objective of this project was to identify genetic, central nervous system, and environmental sources of variability that explain the variations in neurobehavioral outcomes associated with spina bifida meningomyelocele (SBM), the most common severely disabling birth defect in North America. In particular, MEG was used to evaluate the reorganization of motor, somatosensory, language, and cognitive skills in children with SBM, representing one of the first functional neuroimaging studies of children with congenital brain injury. This comprehensive program project sought to facilitate an integrated, multi-disciplinary understanding of SBM, by providing a model for other neurodevelopmental disorders with genetic heterogeneity, brain dysmorphologies, and variable neurobehavioral outcomes while MEG to evaluate the organization of brain functions in children with SBM.

Texas Center For Learning Disabilities (Supported by P50 HD052117-03), Andrew C. Papanicolaou, P.I.

The objective of this study was to use MEG to establish neurological correlates for specific subtypes of learning disabled children and establish features of brain activation profiles associated with adequate and poor response to different interventions. Specifically, the aims of this study were to:

  1. To establish task-specific features of brain activation profiles that characterize specific subtypes of reading disabled (RD) children.
  2. To establish task-specific features of brain activation profiles associated with adequate and poor response to class-wide instructional remediation.
  3. Examine task-specific changes of brain activation profiles associated with adequate response to small-group or individualized, intensive instructional remediation in children who initially failed to benefit from class-wide intervention.
  4. Establish long-term follow up data for children who benefit from systematic classroom based intervention.

More recently, this study has been extended to:

  1. Characterize features of brain organization supporting sentence comprehension, using a multiple task and multimodal imaging approach (MEG, quantitative structural MRI and DTI), to identify print-dependent and print-independent neural components of reading comprehension (RC)--the former associated with sentence reading and word recognition, and the latter associated with executive functions (EFs)--in non-impaired readers and in students experiencing text comprehension difficulties.
  2. Examine the predictive value of pre-intervention multimodal imaging data for subsequent response to intervention.
  3. Investigate functional changes in brain organization following educational interventions by focusing on adequate and inadequate responders to intervention.

By successfully addressing these aims, this project will promote novel directions in cognitive neuroscience research featuring combinations of several multimodal imaging methods, in order to identify features of brain organization that are crucial for typical development of reading comprehension skills and successful intervention outcomes.