Robert Thatcher - Academia.edu (original) (raw)

Papers by Robert Thatcher

Human Brain Mapping, Dec 1, 2008

The purpose of this study was to explore human development of EEG coherence and phase differences... more The purpose of this study was to explore human development of EEG coherence and phase differences over the period from infancy to 16 years of age. The electroencephalogram (EEG) was recorded from 19 scalp locations from 458 subjects ranging in age from 2 months to 16.67 years. EEG coherence and EEG phase differences were computed for the left and right hemispheres in the posteriorto-anterior direction (O1/2-P3/4, O1/2-C3/4, O1/2-F3/4, and O1/2-Fp1/2) and the anterior-toposterior direction (Fp1/2-F3/4, Fp1/2-C3/4, Fp1/2-P3/4, and Fp1/2-O1/2) in the beta frequency band (13-25 Hz). Sliding averages of EEG coherence and phase were computed using 1 year averages and 9 month overlapping that produced 64 means from 0.44 years of age to 16.22 years of age. Rhythmic oscillations in coherence and phase were noted in all electrode combinations. Different developmental trajectories were present for coherence and phase differences and for anterior-to-posterior and posterior-to-anterior directions and inter-electrode distance. Large changes in EEG coherence and phase were present from $ 6 months to 4 years of age followed by a significant linear trend to higher coherence in short distance inter-electrode distances and longer phase delays in long inter-electrode distances. The results are consistent with a genetic model of rhythmic long term connection formation that occurs in cycles along a curvilinear trajectory toward adulthood. Competition for dendritic space, development of complexity, and nonlinear dynamic oscillations are discussed.

JADARA, 2019

deafness on cerebral function, and(3) the relation ship between physiological variables and cogni... more deafness on cerebral function, and(3) the relation ship between physiological variables and cogni tive measures. Further, it was hoped that a Vol. 23 No.

Journal of Neurotherapy, Mar 1, 1998

Journal of Neurotherapy, 2013

Advances in neuroscience are applied to the clinical applications of EEG neurofeedback by linking... more Advances in neuroscience are applied to the clinical applications of EEG neurofeedback by linking symptoms to functional networks in the brain. This is achieved by reviews of the last 20 years of functional neuroimaging studies of brain networks related to clinical disorders based on positron emission tomography, functional MRI, diffusion tensor imaging, and EEG/MEG inverse solutions. Considerable consistency exists between different imaging modalities because of the property of functional localization and the existence of large clusters of connections in the brain representing network modules and hubs. Reviewed here is new method of EEG neurofeedback called Z-Score Neurofeedback, and it is demonstrated how real-time comparison to an age-matched population of healthy subjects simplifies protocol generation and allows clinicians to target modules and hubs that indicate dysregulation and instability in networks related to symptoms. Z-score neurofeedback, by measuring the distance from the center of the healthy age-matched population, increases specificity in operant conditioning and provides a guide by which extreme Z-score outliers are linked to symptoms and then reinforced toward states of greater homeostasis and stability. The goal is increased efficiency of information processing in brain networks related to the patient's symptoms. The unique advantage of EEG over other neuroimaging methods is high temporal resolution in which the fine temporal details of phase lock and phase shift between large masses of neurons is quantified and can be modified by Z-score neurofeedback to address the patient's symptoms. The latest developments in Z-score neurofeedback are a harbinger of a bright future for clinicians and, most important, patients that suffer from a variety of brain dysfunctions.

The human brain weighs about 3 pounds and consumes 40% to 60% of blood glucose. This disproportio... more The human brain weighs about 3 pounds and consumes 40% to 60% of blood glucose. This disproportionate amount of energy is used to create electricity in about 100 billion interconnected neurons. Quantitative electroencephalography (qEEG) is a real-time movie of the electrical activity of the preconscious and conscious mind at frequencies from about 1 Hz to 300 Hz. Numerous studies have cross-validated Electrical Neuroimaging by structural MRI, fMRI and Diffusion Spectral Imaging (DSI) and thereby demonstrated how qEEG can aid in linking patient's symptoms and complaints to functional specialization in the brain. Electrical neuroimaging provides an inexpensive millisecond measure of functional modules including the animation of structures through phase shift and phase lock. Twenty first century Neuropsychiatrists use these methods to link patient's symptoms and complaints to functional specialization in the brain and use this information to implement treatment via Brain-Computer-Interface and neurofeedback technology.

Journal of Alzheimer's Disease, 2022

The COVID-19 pandemic has accelerated neurological, mental health disorders, and neurocognitive i... more The COVID-19 pandemic has accelerated neurological, mental health disorders, and neurocognitive issues. However, there is a lack of inexpensive and efficient brain evaluation and screening systems. As a result, a considerable fraction of patients with neurocognitive or psychobehavioral predicaments either do not get timely diagnosed or fail to receive personalized treatment plans. This is especially true in the elderly populations, wherein only 16% of seniors say they receive regular cognitive evaluations. Therefore, there is a great need for development of an optimized clinical brain screening workflow methodology like what is already in existence for prostate and breast exams. Such a methodology should be designed to facilitate objective early detection and cost-effective treatment of such disorders. In this paper we have reviewed the existing clinical protocols, recent technological advances and suggested reliable clinical workflows for brain screening. Such protocols range from ...

Electroencephalography and Clinical Neurophysiology, 1997

Psychonomic Science, 1966

The effects of electrolytic amygdala lesions on retention of an active avoidance response were in... more The effects of electrolytic amygdala lesions on retention of an active avoidance response were investigated in overtrained and non-overtrained rats. All overtrained rats exhibited normal retention following bilateral amygdala lesions while retention was impaired in three out of four of the nonovertrained rats in which the basolateral nuclei were damaged. These results were interpreted as supporting the hypothesis that the amygdala is primarily involved in acquisition processes and not long-term memory storage. Notes 1. The authors wish to thank John S. Buckley for his valuable assistance in collecting the data and Ruth BreMilIer for the histology, This investigation was supported in part by a Public Health Service Research Grant, MH 08545-03 from the National Institutes of Mental Health, D. P. Kimble, principal investigator.

Journal of Clinical and Experimental Neuropsychology, 1990

Topographic mapping of the cerebral cortex of 79 deaf children and a group of matched hearing chi... more Topographic mapping of the cerebral cortex of 79 deaf children and a group of matched hearing children was performed, using measures of electroencephalographic coherence, phase, and power. Deaf children manifested higher coherence and lower phase in certain left hemispheric areas, suggesting less neural differentiation; but lower coherence and higher phase in certain right hemispheric areas, suggesting greater differentiation. Deaf children had higher total power in bilateral frontal cortex than did hearing children. The data also suggested compensatory functioning in the visual cortex of the deaf subjects. The pattern of results varied somewhat in relation to cause of deafness. These findings support the hypothesis that prelingual deafness results in a partial reorganization of cerebral cortex.

Behavioral Biology, 1977

Averaged evoked potentials (AEPs) were recorded from 11 scalp derivations in subjects participati... more Averaged evoked potentials (AEPs) were recorded from 11 scalp derivations in subjects participating in a delayed letter-matching task. A trial involved presenting a sequence of random dot displays (20 msec in duration), then a letter, then a second series of random dot displays, followed by a second letter. The match and mismatch conditions were equally probable and letter content was counterbalanced across trials. The number of illuminated dots and the retinal area subtended were equal for all displays. AEPs elicited by the random dot displays preceding the first letter differed from AEPs elicited by the random dots following the first letter. Significant differences were also noted between match and mismatch AEPs. The differences occurred primarily between 300 and 400 msec and were maximal in occipital, parietal, and posterior temporal derivations. '1 would like to thank Kim Hopper, Phil Epstein, and Frank Bartlett for helping in the collection of the data and the data analysis. Thanks are also due to Eileen Maisel for reading the preliminary drafts and to E. Roy John for his support and advice.

Neurology, 1999

Objective: To determine whether a previously identified posterior reorganization of the cortical ... more Objective: To determine whether a previously identified posterior reorganization of the cortical motor network after spinal cord injury (SCI) is correlated with prognosis and outcome.Methods: We applied the techniques of high-resolution EEG and dipole source analysis to record and map the motor potentials (MPs) of the movement-related cortical potentials in 44 patients after SCI. Twenty normal controls were also tested. Results were analyzed using a distance metric to compare MP locations. EEG was coregistered with individual specific MR images and a boundary element model created for dipole source analysis.Results: MPs with finger movements were mapped to a posterior location in 20 of 24 tetraplegics compared with normal controls. Two patients, one studied 4 and one 6 weeks after injury, initially had posterior MPs that, on serial testing, moved to an anterior position with recovery. Dipole source localization of the MP generators confirmed these results. Nine of 20 paraplegics had...

Journal of Learning Disabilities, 1983

Hair lead content, intelligence tests, school achievement, and motor impairment assessments were ... more Hair lead content, intelligence tests, school achievement, and motor impairment assessments were obtained from 149 public school children aged 5 to 16. Hair lead concentration significantly discriminated between groups and significantly predicted IQ scores, independent of group classifications. Regression analyses showed a significant negative correlation between lead and intellectual functioning, even in the normal to gifted IQ range. These results demonstrate a continuous inverse relationship between intelligence and relatively low levels of body lead in which the higher levels of cognitive function are affected before any signs of gross motor impairment are seen.

Human Brain Mapping, 2007

The purpose of this study was to compare EEG current source densities in high IQ subjects vs. low... more The purpose of this study was to compare EEG current source densities in high IQ subjects vs. low IQ subjects. Resting eyes closed EEG was recorded from 19 scalp locations with a linked ears reference from 442 subjects ages 5 to 52 years. The Wechsler Intelligence Test was administered and subjects were divided into low IQ (≤90), middle IQ (>90 to <120) and high IQ (≥120) groups. Low‐resolution electromagnetic tomographic current densities (LORETA) from 2,394 cortical gray matter voxels were computed from 1–30 Hz based on each subject's EEG. Differences in current densities using t tests, multivariate analyses of covariance, and regression analyses were used to evaluate the relationships between IQ and current density in Brodmann area groupings of cortical gray matter voxels. Frontal, temporal, parietal, and occipital regions of interest (ROIs) consistently exhibited a direct relationship between LORETA current density and IQ. Maximal t test differences were present at 4 H...

Basic and Clinical Neuroscience Journal, 2021

Introduction: Previous studies have shown that conventional neurofeedback and cognitive modificat... more Introduction: Previous studies have shown that conventional neurofeedback and cognitive modification treatments have numerous psychological benefits for patients with substance use disorders. However, the effectiveness of LORETA (Low-Resolution Brain Electromagnetic Tomography) Z Score Neurofeedback (LZNFB) and cognitive rehabilitation therapy in reducing opioid craving has not been investigated. Thus, the present study aimed to compare the effectiveness of LZNFB and cognitive rehabilitation therapy with Methadone Maintenance Treatment (MMT) in reducing craving in patients with opioid use disorder. Methods: Thirty patients with opioid use disorder undergoing MMT were randomly assigned into three groups: LZNFB with MMT, cognitive rehabilitation with MMT (as experimental groups), and MMT alone control group. The LZNFB and cognitive rehabilitation groups received 20 and 15 sessions of treatment, respectively. The three groups were assessed using several questionnaires and dot-probe tas...

Description, Validation, and Application, 2004

The quantitative digital electroencephalogram (QEEG) was recorded from 19 scalp locations from 62... more The quantitative digital electroencephalogram (QEEG) was recorded from 19 scalp locations from 625 screened and evaluated normal individuals ranging in age from two months to 82 years. After editing to remove artifact, one-year to five-year groupings were selected to produce different average age groups. Estimates of gaussian distributions and logarithmic transforms of the digital EEG were used to establish approximate gaussian distributions when necessary for different

Journal of Neuropsychiatry and Clinical Neurosciences, Aug 1, 1999

The AAN/ACNS report is misleadingly negative regarding the current status of quantitative EEG and... more The AAN/ACNS report is misleadingly negative regarding the current status of quantitative EEG and tends to discourage its development and use with other related clinical problems. There have been many excellent studies showing that QEEG can be useful for the evaluation and understanding of mild traumatic brain injury, learning disabilities, attention deficit disorders, alcoholism, depression, and other types of substance abuse. In fact, Hughes and John recently provided in this Journal an extensive and detailed review of the use of QEEG in psychiatric disorders. The bias of the AAN/ACNS report is also evident when contrasted to the outstanding review of the clinical utility of QEEG by the American Medical EEG Association, which clearly articulates the opposite points in many cases and concludes that QEEG has reached maturity. At present, the most one can say is that there are legitimate scientific debate and differences of opinion concerning the utility of QEEG, as there are in many other areas of medicine. The AAN/ACNS article should not be considered the definitive opinion. Too many implications for health care are at stake. The debate and research may continue without withholding valuable help from the public. We hope that revised guidelines will be drafted in such a way as to encourage the development of quantitative EEG and brain mapping rather than discourage future research support and use of QEEG with patients. Furthermore, we strongly feel that this technology should be available to, and be explored and used by, nonphysicians who are properly trained and certified.

Elsevier eBooks, 2009

Although there are common purposes and applications of normative databases in clinical science, n... more Although there are common purposes and applications of normative databases in clinical science, nonetheless, each type of normative database poses its own special requirements and details. This chapter focuses on quantitative electroencephalographic (QEEG) normative databases. The goal of this chapter is to present the history of the application of scientific standards as they apply to QEEG, and to provide a practical guide for the understanding and evaluation of QEEG normative databases. The chapter illustrates a step-by-step procedure by which any normative EEG database can be validated and sensitivities calculated.

Child and Adolescent Psychiatric Clinics of North America, Jul 1, 2014

The waveforms on an electroencephalogram (EEG) result directly from synaptic activity in brain ne... more The waveforms on an electroencephalogram (EEG) result directly from synaptic activity in brain networks, and neurofeedback offers the opportunity for patients to use operant conditioning to alter their waveforms and brain functioning. Quantitative EEGs (qEEGs) represent a patient's waveforms compared with normative EEG databases and may be corepresented with functional magnetic resonance imaging (fMRI), single-photon emission computed tomography, positron emission tomography (PET), and magnetic resonance imaging. qEEG, modern PET, magnetoencephalography, and fMRI studies concur in showing that the brain is organized by a small set of modules or hubs that represent clusters of neurons characterized by high within-cluster connectivity and sparse long-distance connectivity. During child development, functional brain connectivity is substantially reorganized, but several large-scale network properties seem to be preserved over time, suggesting that functional brain networks in children are organized like other complex systems in adults. Continued