Henry V. Soper

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 lowerfunctioning 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.

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.

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.

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.

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.

Chronic alumina temporal lobe seizures in monkeys.

Abstract Chronic temporal lobe seizures were induced in 11 monkeys by bilateral implantation of aluminum hydroxide into the hippocampi. With unilateral temporal lobe implants of alumina little or no epileptic activity was found; however, with bilateral alumina implants clinical seizures similar to human psychomotor attacks were initiated in either of the affected temporal lobes. Spread of alumina through the ventricles and/or tissue in some animals resulted in other seizure types, most of which could be controlled by phenobarbital, without eliminating the temporal lobe seizures. The alumina temporal lobe seizures recurred spontaneously for indefinitely long periods; however, no monkey was studied longer than 14 months. The onset of seizure activity was followed by transient anorexia and adipsia which, with large alumina volumes or other debilitating factors, could progress to fatal status epilepticus. Histology revealed that tissue reactions to the alumina included cell loss, gliosis, and neovascularization, with the most severe reaction occurring adjacent to the alumina mass. Alumina which had leaked into the ventricles in some animals reentered the brain tissue at remote sites through the choroid plexus, resulting in multiple foci.

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 Alzheimers 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.

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 longterm 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.

Effects of Chronic Cerebellar Stimulation on Chronic Limbic Seizures in Monkeys

Summary: 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 paramétérs 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.