ABSTRACT
OBJECTIVE: We examined the influence of depression and anxiety on executive function in individuals with a DSM-IV diagnosis of anorexia nervosa-restricting type, anorexia nervosa-binge-eating/purging type, bulimia nervosa, or eating disorder not otherwise specified. METHOD: We assessed 106 women after their inpatient treatment in an eating disorders program. All participants were nutritionally stable at the time of testing. RESULTS: Thirty percent of the total sample showed impaired performance on one or more tests of executive function. No differences in executive function were observed among diagnostic groups. Anxiety scores accounted for significant variance in performance for all groups. DISCUSSION: Executive function deficits were found in a minority of our sample, with significant variance in performance accounted for by self-reported anxiety. State anxiety appears to contribute to diminished executive function in women with eating disorders.
Subject(s)
Anxiety/psychology , Executive Function , Feeding and Eating Disorders/psychology , Adolescent , Adult , Depression/psychology , Diagnostic and Statistical Manual of Mental Disorders , Feeding and Eating Disorders/diagnosis , Female , Humans , Neuropsychological TestsABSTRACT
We compared functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) for the mapping of receptive language function. Participants performed the same language task in the two different imaging environments. MEG activation profiles showed prominent bilateral activity in superior temporal gyrus and left-lateralized activity in middle temporal gyrus. fMRI activation profiles revealed bilateral activity in prefrontal, superior temporal, middle temporal, and visual areas. Laterality quotients derived from the two modalities showed poor agreement between the two methods for commonly active regions of interest. Locations of peak activity also varied considerably within participants between the two methods.
Subject(s)
Brain Mapping/methods , Brain/physiology , Language , Magnetic Resonance Imaging/methods , Magnetoencephalography/methods , Nerve Net/physiology , Speech Perception/physiology , Adult , Evoked Potentials, Auditory/physiology , Female , Humans , MaleABSTRACT
OBJECTIVE: The purpose of this study was to evaluate the reproducibility of estimates of neurophysiological activity obtained with Magnetic Source Imaging. METHODS: Split-half data sets were obtained from 14 healthy volunteers during performance of a continuous recognition task for spoken words. The concurrent validity of spatiotemporal activation maps obtained with this task has been previously verified through comparisons with the Wada test and electrocortical stimulation mapping. Consecutive late activity sources (> 200 ms after stimulus onset) were modeled independently as equivalent current dipoles (ECDs) and used to identify the location of language-specific cortex in the left hemisphere (Wernicke's area). RESULTS: Linear displacement of the geometric center of the cluster of ECDs in this region ranged between 2 and 8 mm across subjects. Intraparticipant variability (range) in the onset latency of activity was +/-50 ms, while the range of change in global field power for the entire set of ECDs in Wernicke's area was less than 17% in all cases. CONCLUSIONS: The results indicate that despite its many conceptual limitations the ECD model can provide reliable estimates of regional cortical activity associated with the engagement of linguistic processes. SIGNIFICANCE: The results highlight the need for reproducibility studies when research questions pose particular requirements for precision of estimates of regional neurophysiological activity.
Subject(s)
Temporal Lobe/physiopathology , Adult , Algorithms , Attention/physiology , Cerebral Cortex/physiopathology , Fatigue/physiopathology , Female , Habituation, Psychophysiologic/physiology , Humans , Magnetic Resonance Imaging , Magnetoencephalography , Male , Middle Aged , Motivation , Reproducibility of ResultsABSTRACT
PURPOSE: To characterize the relation between hemispheric asymmetries in language-specific brain activity and reading/spelling achievement by using magnetoencephalography (MEG). METHODS: Patients (n = 83) with medically intractable complex partial seizures of either left- or right-hemisphere origin were classified as having reading and/or spelling deficits (RS) or as not impaired (NI) by using standard achievement tests. All patients had undergone noninvasive functional mapping of receptive language cortex by using MEG as part of a preoperative seizure surgery evaluation. RESULTS: RS patients with left-hemisphere seizure onset exhibited relatively greater activation and earlier onset of late, language-specific MEG activity in posterior temporal and inferior parietal areas of the right as compared with the left hemisphere than did NI patients. These findings also were evident on an individual basis and were independent of global intellectual abilities. CONCLUSIONS: Reading and spelling achievement deficits in patients with complex partial seizures of left-hemisphere origin are associated with atypical language organization, possibly secondary to reorganization of language function to right-hemisphere areas that are not as efficient as homotopic areas in the left hemisphere in supporting reading and spelling functions.
Subject(s)
Epilepsy, Complex Partial/diagnosis , Functional Laterality/physiology , Language , Learning Disabilities/diagnosis , Magnetoencephalography/statistics & numerical data , Parietal Lobe/physiology , Temporal Lobe/physiology , Achievement , Adolescent , Adult , Brain Mapping , Child , Chronic Disease , Comorbidity , Dyslexia/diagnosis , Epilepsy, Complex Partial/epidemiology , Epilepsy, Complex Partial/surgery , Female , Humans , Intelligence Tests , Learning Disabilities/epidemiology , Male , Middle Aged , Preoperative Care , Retrospective StudiesABSTRACT
Advances in neuroimaging technologies over the last 15 years have prompted their relatively widespread use in the study of brain mechanisms supporting language function in children and adults. We reviewed reliability and external validity studies of 3 of the most common functional imaging methods, functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), and positron emission tomography (PET). Although reliability and validity reports for fMRI are generally quite favorable, significant variability was found across studies with respect to methodology, preventing in some cases either the assessment of the reliability of individual datasets, or cross-study comparisons. Reliability and validity reports of MEG are strong, yet methodological questions regarding optimal modeling techniques remain. PET investigators report good concordance of language maps with data from more invasive brain mapping techniques, but its use of radioactive tracers and poorer spatial and temporal resolution make it the least optimal of the 3 methods for language mapping. Investigations of the cortical networks supporting language function during development and into adulthood should be viewed in the context of the validity and reliability of the methods used, with careful attention to details regarding the methodologies employed in the acquisition and analysis of statistical maps.
