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Biomedical subjects

H V Soper

Publications and source records attributed to H V Soper.

At least 19 recordsLinked to original sources

Vigorous, aerobic exercise versus general motor training activities: effects on maladaptive and stereotypic behaviors of adults with both autism and mental retardation.

Examined the effects of antecedent exercise conditions on maladaptive and stereotypic behaviors in 6 adults with both autism and moderate to profound mental retardation. The behaviors were observed in a controlled environment before and after 2 exercise and 1 non-exercise conditions. From the original group of 6 participants, 2 were selected subsequently to participate in aerobic exercise immediately before performing a community-integrated vocational task. Only antecedent aerobic exercise significantly reduced maladaptive and stereotypic behaviors in the controlled setting. Neither of the less vigorous antecedent conditions did. When aerobic exercise preceded the vocational task, similar reductions were observed. There were individual differences in response to antecedent exercise. Use of antecedent aerobic exercise to reduce maladaptive and stereotypic behaviors of adults with both autism and mental retardation is supported.

Activities of Daily Living↗

Analog language teaching versus natural language teaching: generalization and retention of language learning for adults with autism and mental retardation.

Examined the effects of two instructional methods on language generalization and long-term retention in 23 adults with autism and severe to profound mental retardation. Analog language teaching employed discrete trials in a controlled setting concentrating on discrimination and identification of materials. Natural language teaching emphasized instruction through interactions that occurred incidentally to training students in the use of materials to perform functional tasks. Assessments were conducted under conditions favoring analog teaching to assure against partiality toward natural language teaching. Under such disadvantageous conditions, the methods of natural language teaching would be supported by results showing either no difference or an advantage in their favor. Both techniques increased initial and long-term generalization though the results suggest no relative superiority for either method under these assessment conditions. A significant interaction was found between prior functioning level and sequence of instruction. Because natural language teaching has many strengths, few drawbacks, and produces equal generalization and retention under disadvantageous conditions, it is strongly supported as preferable for people with autism and mental retardation.

Adolescent↗

Effects of fenfluramine on neuropsychological and communicative functioning in treatment-refractory schizophrenic patients.

Reported behavioral improvement among autistic patients following feufluramine treatment and a high serotonin level among certain chronic schizophrenic patients suggested that fenfluramine treatment might be beneficial with such schizophrenic patients, especially within the realm of neuropsychological and communicative functioning. A brief neuropsychological battery was administered to eight chronic schizophrenic subjects before, during, and after fenfluramine treatment. Conversations in controlled settings were audiotaped before and during fenfluramine treatment for seven of these subjects and one additional subject. These language samples were analyzed for communicative competence and evidence of thought disorder. Overall, neuropsychological and communicative functioning was worse under the fenfluramine condition, even though blood serotonin levels were about half those at baseline conditions. The results suggest that it is not the higher levels of blood serotonin by themselves that are related to depressed neuropsychological, communicative, and other functioning. In fact, the higher levels of serotonin may well be related to adaptations for maximal level of functioning. These results suggest caution in the use of fenfluramine for other schizophrenic populations.

Adult↗

Null hypothesis disrespect in neuropsychology: dangers of alpha and beta errors.

To understand why there are so many inconsistencies and contradictory findings among hemispheric-asymmetry studies, data were analyzed from a large study of 300 left-handers. These data included information on familial sinistrality (FS), handwriting posture (HPO), a measure of cognitive performance, and five measures of hemispheric specialization. Using computer simulation methodology, 40 independent samples of 36 to 65 subjects each were drawn randomly with replacement. The sample data were analyzed and the results compared to those of the parent "population." Often, the samples poorly reflected the parent "population," and some procedures substantially inflated error rates. These procedures are discussed and specific guidelines suggested. These results are also discussed in the broader context of the necessity for investigators in neuropsychology to differentiate between the statistical and clinical significance of research findings; and to develop a more positive attitude toward the design, execution, and publication of replication studies.

Adult↗

WAIS-R marker for dementia of the Alzheimer type? An empirical and statistical induction test.

A specific WAIS subtest pattern has recently been shown to occur more frequently in cases of dementia of the Alzheimer's type (DAT) than in cases of multi-infarct dementia (Fuld, 1984; Brinkman & Braun, 1984). To date, only one study has examined the frequency of this WAIS pattern in a normal elderly sample and found it to be infrequent (Tuokko & Crocket, 1987). If replicated on a larger sample of normals, it would increase the potential of this pattern as a behavioral marker of DAT. WAIS-R scores (age-corrected) were analyzed on a sample of 149 healthy volunteers (ages 60-94) who were part of an ongoing aging study. Because only 12% of the sample revealed this WAIS pattern, its utility as a conditional marker of DAT in three different hypothetical clinical base rate settings was evaluated. Results provided cautious optimism for the application of this marker in certain clinical settings.

Aged↗

Handedness distribution in a residential population with severe or profound mental retardation.

Handedness within a sample of mentally retarded subjects was assessed using a procedure that includes a large number of items appropriate for lower functioning subjects, with multiple presentations within and between sessions one week apart. Results revealed a dramatic shift from the normal right-handed bias primarily due to the presence of a large mixed-handedness subtype, which proved to be ambiguously handed in that these subjects showed inconsistent hand preference within items. Reasons why this subtype has not been reported previously were discussed, and a model was postulated to explain the resultant handedness distribution in terms of probable central nervous system substrate.

Adult↗

Handedness patterns in autism suggest subtypes.

The present study reports preliminary data from two unselected samples of carefully diagnosed autistic subjects (children and adults) and an assessment procedure that includes a large sample of items, appropriate for lower-functioning autistic subjects, with multiple presentations within and between sessions 1 week apart. The study seeks to determine (1) whether a raised incidence of non-right-handedness exists in these samples (2) if so, what constructs best represent this shift in the handedness distribution (i.e., phenotype and CNS substrate) and (3) whether these handedness phenotypes are associated with different levels of cognitive functioning. The results reveal a dramatic shift away from right-handedness in both autistic samples, due to a raised incidence of two phenotypes, manifest left-handedness and ambiguous handedness. The ambiguously handed, who were postulated to represent substantial bilateral CNS pathology due to early brain injury, were found to have much lower intellectual scores in one of the study samples.

Adolescent↗

Left-handedness, dyslexia, and autoimmune disorder: a critique.

Concerns are raised regarding recent claims of an association between left-handedness and autoimmune disease and/or dyslexia. The available data provide only marginal support at best for these claims which, in addition, contain potentially misleading implications about left-handedness. Furthermore, some of the theoretical bases for the proposed associations are inconsistent with the relevant literature. Revisions in the theory are suggested to make it more consistent with the literature and to foster alternative explanations for a n autoimmune disease and dyslexia.

Autoimmune Diseases↗

The role of familial sinistrality in cerebral organization.

The literature on the relationship between familial sinistrality (FS) and laterality is conflicting. A large scale investigation employing multiple measures of laterality assessment and rigorous methods of handedness and FS determination was conducted with a normal population of left- and right-handers. The results failed to find a relationship between FS and hemispheric representation of speech despite the fact that a robust relationship was found between handedness and hemispheric speech specialization. Possible reasons for these null findings are discussed.

Adolescent↗

Cautions in alternate-form presentation of aural test material: Speech Sounds Perception Test.

86 college students were administered the standard Speech Sounds Perception Test and an alternate recording. Although reliability between the two recordings was moderate (r = .68) when the standard was given first, but only .36 when the alternate form was given first, differences in performance were consistent with differences in attack and decay found in voice-print tracings. Results suggest caution in using an alternate form of a neuro-psychological test, particularly one using auditory stimuli, until cross-validation confirms the reliability coefficient and the level of performance.

Adult↗

Pathological left-handedness and ambiguous handedness: a new explanatory model.

A new model is presented which attempts to explain three pathological handedness phenotypes: pathological left-handedness (PLH), pathological right-handedness (PRH) and ambiguous handedness (AH). Revisions in the original model of PLH were prompted in order to account for reports of a raised incidence of both manifest left-handedness and AH in more severely retarded and/or brain-injured populations--namely, autistic. The new model generates specific predictions on the likelihood of different etiological subgroups within these disorders.

Autistic Disorder↗

Principal sulcus and posterior parieto-occipital cortex lesions in the monkey.

In order to assess the roles of the posterior parieto-occipital and principal sulcus cortices in processing spatial information, both with and without delays, monkeys were given lesions of one or the other area or no lesion and tested on a series of conditional discrimination tasks. There were six basic tasks, and the cue locations differed from the response locations within each task. The first two had mixed dimensions in that the location of the cue indicated the color of the correct response alternative or the color of the cue indicated the correct response location. The animals were trained preoperatively on these tasks and then tested for postoperative retention. For the next two tasks color was the only relevant dimension, but different colors were used for the cues and response alternatives. For the final two tasks location was the only relevant dimension. When an animal learned a given task it was subsequently tested on it with a 5-sec. delay. The deficits observed suggest that the roles of these areas can not be expressed simply in terms of spatial or delay functions. No group appeared to be impaired on any delay task on which it was tested. The animals with the posterior cortex removed had a great deal of difficulty in using information from one dimension to identify the correct response alternative by the other dimension, but not when the relevant cue and response dimensions were the same. These results suggest that the posterior parieto-occipital area is involved in making associations across dimensions with in the visual modality. The animals with the principal sulcus removed appeared to have difficulty only when they were required to respond with reference to the colors of the response alternatives. On such tasks the relevant dimension (color) was not available until the presentation of the response array. On the other tasks the correct response location could be determined from the cue presentation alone, that is, before the presentation of the response array. This suggests that these animals had a tendency to respond without reference to the color dimension, but rather just to the presentation of the response array, and therefore a principal sulcus function of inhibiting a response until the appropriate information has been processed.

Animals↗

Effects of chronic cerebellar stimulation on chronic limbic seizures in monkeys.

No influences of chronic cerebellar stimulation were found in 10 different controlled experiments in 5 different monkeys with chronic alumina-induced psychomotor seizures. The stimulation parameters used were comparable to those used in human epileptics, and continuous daily EEG and behavioral monitoring allowed all seizures to be measured for daily frequency and duration over the several weeks of the experiments. Nocturnal seizures were similarly quantified in 3 monkeys to verify that cerebellar stimulation did not affect them. Motor cortex potentials evoked by cerebellar pulses confirmed that the stimulations were activating the cerebellum throughout the experiments, and measures of electrode access resistance and impedance verified that the electrodes remained in contact with the cerebellum. In one monkey given phenobarbital medication, interictal morbid behavior appeared to be improved by chronic stimulation of either cerebellum or dorsolateral frontal cortex, thus indicating an arousal influence of brain stimulation not due to cerebellum per se.

Aluminum Hydroxide↗

A sample and hold amplifier system for stimulus artifact suppression.

A sample and hold amplifier system has been described which is capable of eliminating stimulus artifacts from a variety of biological recordings which would otherwise be impossible to interpret during electrical stimulation. Factors contributing to the prolongation of stimulus artifact are discussed in relation to the design requirements of this system. The application of this artifact suppression circuit to monitoring EEG seizures during electrical stimulation is demonstrated.

Amplifiers, Electronic↗

Electrophysiological studies of long-term electrical stimulation of the cerebellum in monkeys.

Six rhesus monkeys were stimulated on the paravermal cortex for 205 hours (18 days) with different charge densities in order to determine the electrode performance and neural damage that may result from long-term cerebellar stimulation comparable to that being used in man. The electrode-tissue interface was relatively stable and no neural damage was found when the charge/phase (0.5 muC/ph) or charge density (7.4 muC/sq cm/ph) was very low. At all higher charge levels tested (2.4, 4.8, 10, and 22 muC/ph), changes in the electrode-tissue interface, meningeal encapsulation, and neural damage were directly related to the charge density delivered. Unstimulated electrodes on the opposite paravermal cortex exhibited mild tissue reactivity and cell damage, probably due to mechanical compression of the molecular layer and pial vessels. Motor cortex field potentials could be evoked by charges as low as 0.1 muC/ph delivered to paravermal cortex; for a given charge/phase longer pulses were more effective than short pulses. After neural damage resulting from 205 hours of 4.8 muC pulses at 10 per second (total charge 14.76 C), the threshold for the motor cortex evoked potential increased by a factor of four or more. With the charge held constant to different-sized electrodes placed bilaterally in the same monkey, damage was greater under the smaller electtrode. This finding suggests that the charge density to cerebellar cortex must be controlled to avoid neural damage.

Animals↗

Tissue reactions to long-term electrical stimulation of the cerebellum in monkeys.

Light and electron microscopic analyses were carried out on the stimulated and unstimulated paravermal cortices of six rhesus monkeys that had electrodes implanted on their cerebella for 2 months. The electrodes and the stimulation regime (10 p.p.s.: 8 min on, 8 min off) were similar to those used to stimulate the human cerebellum for treatment of certain neurological disorders. Mere presence of the electrode array in the posterior fossa for 2 months resulted in some meningeal thickening, attenuation of the molecular layer, and loss of Purkinje cells immediately beneath the electrode array. There was no evidence of scarring. After 205 hours of stimulation (7.35 X 10(6) pulses) over 18 days, a charge of 0.5 muC/ph or estimated charge density of 7.4 muC/sq cm/ph resulted in no damage to the cerebellum attributable to electrical stimulation per se. Such a charge/phase is about five times the threshold for evocation of cerebellar efferent activity, and might be considered "safe" for stimulation of human cerebellum. Charge density/phase and charge/phase were directly related to increased cerebellar injury in the six other cerebellar cortices stimulated. Leptomeningeal thickening increased with increased charge density. Injury included severe molecular layer attenuation, ongoing destruction of Purkinje cells, gliosis, ongoing degeneration of myelinated axons, collagen intrusion, and increased levels of local polysaccharides. In all cases, even with damage that destroyed all conducting elements beneath the electrodes, there was no damage further than 1 to 2 mm from the edges of the electrode arrays.

Animals↗