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Todd Richards

Publications and source records attributed to Todd Richards.

12 recordsLinked to original sources
PubMed2005

Anatomical signatures of dyslexia in children: unique information from manual and voxel based morphometry brain measures.

Thirteen male control and thirteen male dyslexic children (age, 121-152 months) were studied to determine if voxel based morphometry (VBM) could identify anatomical differences in the right cerebellar anterior lobe, and right and left pars triangularis that were identified with manual measures of the same children. VBM demonstrated significant gray and white matter differences in these three brain regions. In contrast to the manual results, these differences were not significant after controlling for brain volume, suggesting the manual measures captured additional important variance that distinguished the groups. Post-hoc VBM comparisons demonstrated white matter volume differences in a left temporal-parietal region that are consistent in location with results from diffusion tensor imaging studies of dyslexia. The VBM analyses also identified, gray matter volume differences in the left and right lingual gyrus, left inferior parietal lobule and cerebellum, areas that had not been examined with manual methods. We conclude that manual and automated methods provide valuable and complementary approaches to the search for functionally significant neurobiological characteristics of dyslexia.

Brain↗
PubMed2005

Evidence for correlations between distant intentionality and brain function in recipients: a functional magnetic resonance imaging analysis.

This study, using functional magnetic resonance imaging (fMRI) technology, demonstrated that distant intentionality (DI), defined as sending thoughts at a distance, is correlated with an activation of certain brain functions in the recipients. Eleven healers who espoused some form for connecting or healing at a distance were recruited from the island of Hawaii. Each healer selected a person with whom they felt a special connection as a recipient for DI. The recipient was placed in the MRI scanner and isolated from all forms of sensory contact from the healer. The healers sent forms of DI that related to their own healing practices at random 2-minute intervals that were unknown to the recipient. Significant differences between experimental (send) and control (no send) procedures were found (p = 0.000127). Areas activated during the experimental procedures included the anterior and middle cingulate area, precuneus, and frontal area. It was concluded that instructions to a healer to make an intentional connection with a sensory isolated person can be correlated to changes in brain function of that individual.

Adult↗
PubMed2004

Regional patterns of brain metabolites in AIDS dementia complex.

The relationship of the cellular changes in the HIV-infected brain to the onset and progression of AIDS dementia complex (ADC) remains uncertain. We undertook an in vivo proton magnetic resonance spectroscopy (MRS) study and used factor analysis to identify specific cellular and regional brain changes that may serve as metabolic markers of ADC. The ratio of N-acetyl aspartate (NAA), choline (Cho), and myoinositol (MI) over creatine (Cr), markers of neuronal and glial cell metabolism, were measured in the basal ganglia, centrum semiovale, and parietal cortex from 100 subjects with and without ADC. Three metabolic patterns were identified, which we termed "inflammatory" (mainly MI/Cr elevations in all three regions plus Cho/Cr increases in the centrum semiovale and parietal cortex), "basal ganglia" (mostly NAA/Cr and Cho/Cr elevations in the basal ganglia), and "neuronal" (primarily NAA/Cr reductions in the centrum semiovale and the parietal cortex). Logistic regression analysis revealed that, adjusted for age, basal ganglia and neuronal pattern scores were strongly associated with ADC but inflammatory levels were not. We conclude that by using factor analysis, we are able to combine multiple metabolites across brain regions in a biologically plausible manner and construct a predictive model of ADC adjusting for relevant factors such as age.

AIDS Dementia Complex↗
PubMed2004

Manipulating presence influences the magnitude of virtual reality analgesia.

Excessive pain during medical procedures performed in unanesthetized patients is frequently reported, but can be reduced with virtual reality (VR) distraction. Increasing the person's illusion of going into the virtual world may increase how effectively VR distracts pain. Healthy volunteers aged 18-20 years participated in a double-blind between-groups design. Each subject received a brief baseline thermal pain stimulus, and the same stimulus again minutes later with either a Low Tech or a High Tech VR distraction. Each subject provided subjective 0-10 ratings of cognitive, sensory and affective components of pain, and rated their illusion of going inside the virtual world. Subjects in the High Tech VR group reported a stronger illusion of going into the virtual world (VR presence) than subjects in the Low Tech VR group, (4.2 vs. 2.5, respectively, P = 0.009) and more pain reduction (reduction of worst pain is 3.1 for High Tech VR vs. 0.7 for Low Tech VR, P < 0.001). Across groups, the amount of pain reduction was positively and significantly correlated with VR presence levels reported by subjects ( r = 0.48 for 'worst pain', P < 0.005).

Adolescent↗
PubMed2004

Electroencephalographic evidence of correlated event-related signals between the brains of spatially and sensory isolated human subjects.

OBJECTIVE: To determine whether correlated event-related potentials (ERPs) can be detected between the brains of spatially and sensory isolated human subjects. DESIGN AND SETTING: Simultaneous digitized electroencephalograms (EEGs) were recorded from the occipital area in pairs of human subjects placed in sound attenuated rooms separated by 10 meters. One person relaxed in one of the rooms while the other received visual stimulation while in the other room. Prior to each experiment, members of the pair were randomly designated as sender and receiver. Sessions were subsequently repeated with subjects reversing their roles. Previous to each session, the sender was instructed "to attempt sending an image/thought." The receiver was instructed "to remain open to receive any image/thought from his/her partner." Alternating stimulus-on/stimulus-off conditions were presented throughout the session to the sender, while a stimulus-off condition was presented to the receiver. SUBJECTS: Thirty-seven (37) female, and 23 male subjects (n = 60; 30 pairs) participated in the study. Subjects knew each other well and claimed to have previous experience of being emotionally/psychologically connected to one another. OUTCOME MEASURES: A Runs test was applied to compare EEG "hits" in the receiver's EEG during the sender' stimulus-on condition versus sender's stimulus-off conditions. Test results at p < 0.01 were considered evidence of correlated brain signals. Pairs in whom at least one member had significant results were invited back for replication. RESULTS: Of the 60 subjects tested, 5 (4 women/1 man) showed significantly higher brain activation (p < 0.01) during their sending partner's stimulus-on condition as compared to stimulus-off condition. Using the Stouffer z meta-analytic method all receiver EEG results across all 60 subjects were combined by transforming the individual session p values into z scores. Data analyses showed overall significant results for EEG data recorded during the flickering condition (z =-3.28, p = 0.0005) as well as nonsignificant results for data recorded during the static condition (z = 0.35, p = 0.64). Four pairs participated in a replication experiment during which one pair replicated the effect. CONCLUSIONS: These results indicate that in some pairs of human subjects a signal may be detected in the brain of a distant member of the pair when the brain of the other member is visually stimulated. These data support the findings of similar studies performed in seven laboratories reported in the peer-reviewed literature since 1963. Research in this area should now proceed with investigation of its physical and biologic mechanism, its generalizability to varying populations and relationships, and its clinical application.

Adult↗
PubMed2003

Anesthetic considerations in patients with Alzheimer's disease.

Alzheimer's disease is a form of dementia that is estimated to affect approximately 3 to 4 million Americans. Given the substantial number of people affected with this disease, it is likely that anesthesiologists will encounter many patients with Alzheimer's disease. Questions as to potential problems including informed consent, drug interactions, and preoperative progression of the disease may arise. This review describes anesthetic considerations, including pharmacologic and physiologic issues, in this growing population.

Aged↗
PubMed2003

The illusion of presence in immersive virtual reality during an fMRI brain scan.

The essence of immersive virtual reality (VR) is the illusion it gives users that they are inside the computer-generated virtual environment. This unusually strong illusion is theorized to contribute to the successful pain reduction observed in burn patients who go into VR during woundcare (www.vrpain.com) and to successful VR exposure therapy for phobias and post-traumatic stress disorder (PTSD). The present study demonstrated for the first time that subjects could experience a strong illusion of presence during an fMRI despite the constraints of the fMRI magnet bore (i.e., immobilized head and loud ambient noise).

Adult↗
PubMed2003

Surgical management of foramina parietalia permagna.

Enlarged parietal foramina are rare congenital skull defects identified on physical examination and confirmed radiographically. They are round or oval defects situated on each parietal bone approximately 1 cm from the midline and 2 to 3 cm superior to the lambdoid suture. Although small parietal foramina are common variants in up to 60% to 70% of normal skulls, large parietal foramina ranging from 5 mm to multiple centimeters are less common, with a prevalence of 1:15,000 to 1:25,000. We present a case series of four patients with large persistent parietal foramina managed surgically for the correction of this deformity. Two infants were treated with autologous calvarial bone grafts, and two were treated with a mesh plating system and hydroxyapatite. No patient developed any perioperative complications. No perioperative or delayed infections occurred in our patient population. The mean postoperative follow-up was 36 months. One patient required a second procedure with methylmethacrylate because of late bone graft failure, whereas the others were successfully treated by the initial procedure. Foramina parietalia permagna, otherwise known as fenestrae parietals symmetricae, enlarged parietal foramina, giant parietal foramina, or Catlin marks, are a rare clinical entity. A spontaneous decrease in the size of these defects with growth of the infant has been reported, but this closure is usually incomplete. Surgical intervention of persistent large foramina protects the child against potential injury to the underlying brain. We advocate cranioplasty for active young children and those at risk for injury (i.e., seizure disorder) to decrease the risk for potential intracranial injury.

Biocompatible Materials↗
PubMed2003

Autosomal dominant polycystic kidney disease--clinical challenges.

While not very common, the clinical anesthesiologist can expect to see between two and three patients per year with autosomal dominant polycystic kidney disease, ADPKD. Careful education and proper planning are essential to assure appropriate care for these patients. In addition, co-morbid conditions associated with the disease, make it especially challenging for the anesthesiologist who must be prepared for all contingencies. Also, decreased renal function and the systemic effects combine to create unique problems in properly anesthetizing these patients. Finally, proper preoperative assessment is essential to protect patients with ADPKD, and special care should be taken to select drugs that rely on non-renal metabolism for excretion. This review summarizes anesthetic considerations regarding epidemiologic, diagnostic, genetic, and perioperative clinical issues related to this disease.

Humans↗
PubMed2002

Defining the broader phenotype of autism: genetic, brain, and behavioral perspectives.

Achieving progress in understanding the cause, nature, and treatment of autism requires an integration of concepts, approaches, and empirical findings from genetic, cognitive neuroscience, animal, and clinical studies. The need for such integration has been a fundamental tenet of the discipline of developmental psychopathology from its inception. It is likely that the discovery of autism susceptibility genes will depend on the development of dimensional measures of broader phenotype autism traits. It is argued that knowledge of the cognitive neuroscience of social and language behavior will provide a useful framework for defining such measures. In this article, the current state of knowledge of the cognitive neuroscience of social and language impairments in autism is reviewed. Following from this, six candidate broader phenotype autism traits are proposed: (a) face processing, including structural encoding of facial features and face movements, such as eye gaze; (b) social affiliation or sensitivity to social reward, pertaining to the social motivational impairments found in autism; (c) motor imitation ability, particularly imitation of body actions; (d) memory, specifically those aspects of memory mediated by the medial temporal lobe-prefrontal circuits; (e) executive function, especially planning and flexibility; and (f) Language ability, particularly those aspects of language that overlap with specific language impairment, namely, phonological processing.

Autistic Disorder↗
PubMedDate not supplied

Writing and reading: connections between language by hand and language by eye.

Four approaches to the investigation of connections between language by hand and language by eye are described and illustrated with studies from a decade-long research program. In the first approach, multigroup structural equation modeling is applied to reading and writing measures given to typically developing writers to examine unidirectional and bidirectional relationships between specific components of the reading and writing systems. In the second approach, structural equation modeling is applied to a multivariate set of language measures given to children and adults with reading and writing disabilities to examine how the same set of language processes is orchestrated differently to accomplish specific reading or writing goals, and correlations between factors are evaluated to examine the level at which the language-by-hand system and the language-by-eye system communicate most easily. In the third approach, mode of instruction and mode of response are systematically varied in evaluating effectiveness of treating reading disability with and without a writing component. In the fourth approach, functional brain imaging is used to investigate residual spelling problems in students whose problems with word decoding have been remediated. The four approaches support a model in which language by hand and language by eye are separate systems that interact in predictable ways.

Adult↗