USAF take-off and landing ejections, 1973-85.

Ejection on or near the ground appears potentially injurious, especially since the survival rate decreases as altitude of ejection decreases. Ejection data from 1973 through 1985 were reviewed to analyze whether ground-level take-off and landing ejections posed an increased risk of injury or death. This review included only ejections clearly requiring a decision between ground egress and ejection.

Localization of human sensorimotor cortex during surgery by cortical surface recording of somatosensory evoked potentials.

The traditional means of localizing sensorimotor cortex during surgery is Penfield's procedure of mapping sensory and motor responses elicited by electrical stimulation of the cortical surface. This procedure can accurately localize sensorimotor cortex but is time-consuming and best carried out in awake, cooperative patients. An alternative localization procedure is presented that involves cortical surface recordings of somatosensory evoked potentials (SEP's), providing accurate and rapid localization in patients under either local or general anesthesia.

Plasma patterns of LH, FSH and prolactin in rats with a polycystic ovarian condition induced by oestradiol valerate.

The patterns of plasma LH, FSH and prolactin concentrations were investigated in rats with a polycystic ovary condition (PCO). The condition was induced by treatment with oestradiol valerate 9 weeks before blood sampling. Serial blood samples were taken at 10-min intervals for 4 h from ten rats with PCO.

High frequency jet ventilation for bilateral bullectomy.

This case report describes the use of high frequency jet ventilation for resection of bilateral lung bullae. Low airway pressures reduced the risk of pulmonary barotrauma. A continuous infusion of ketamine provided acceptable anaesthesia.

Intracranial recordings of endogenous ERPs in humans.

Target detection and stimulus omission tasks of the type used to elicit scalp P300 and related potentials were studied in a group of 40 patients in whom intracranial electrodes had been implanted during evaluation for epilepsy surgery. Two distinct task-related intracranial ERP patterns have been identified, one in the medial temporal lobe and the other in the frontal lobe. These patterns overlap in time with each other and with scalp P300.

Three children with partial trisomy 1q and partial monosomy 3p.

We report a kindred in which three children suffer from partial trisomy 1q and partial monosomy 3p, transmitted by a balanced translocation which is maternal in one family and paternal in the other. The clinical features of the three children are similar and include severe mental handicap and severe scoliosis in the older two.

The influence of chlormethiazole in comparison to thioridazine on body temperature and postural hypotension in healthy adults and healthy elderly volunteers.

Certain drugs used to treat the elderly are known to precipitate hypothermia. In this study, the effects of chlormethiazole and thioridazine in producing postural hypotension were compared. In a study of hypothermia in the elderly the effects of chlormethiazole, thioridazine and lormetazepam were examined.

Scalp distributions of event-related potentials: an ambiguity associated with analysis of variance models.

Analysis of variance (ANOVA) interactions involving electrode location are often used to assess the statistical significance of differences between event-related potential (ERP) scalp distributions for different experimental conditions, subject groups, or ERP components. However, there is a fundamental incompatibility between the additive model upon which ANOVAs are based and the multiplicative effect on ERP voltages produced by differences in source strength. Using potential distributions generated by dipole sources in spherical volume conductor models, we demonstrate that highly significant interactions involving electrode location can be obtained between scalp distributions with identical shapes generated by the same source.

Event-related potentials, lexical decision and semantic priming.

ERPs were recorded during a lexical decision task in order to investigate electrophysiological concomitants of semantic priming. The stimuli were 240 words and 240 nonwords presented one per trial at a fixed intertrial interval. Subjects were required to classify each stimulus as a word or nonword by pressing one of two response buttons.

Principal component analysis of event-related potentials: simulation studies demonstrate misallocation of variance across components.

Simulated event-related potential (ERP) components were used to investigate the ability of principal component analysis (PCA), Varimax rotation and univariate analysis of variance (ANOVA) to reconstruct component wave shapes, to allocate variance correctly across components, and to identify the correct locus of simulated experimental treatments. The simulated ERPs consisted of 800 randomly weighted combinations of three 64-point components, corresponding to a 2 X 2 X 10 repeated-measures design with 20 subjects. Covariance PCAs, Varimax rotations and univariate ANOVAs were performed on each of 400 such simulations, 100 with no effect of any experimental treatment and 100 each with main effects on each of the 3 components.

When words collide: orthographic and phonological interference during word processing.

The interaction between orthographic and phonological information was studied in two experiments by requiring subjects to match visually presented word pairs on the basis of their visual or rhyming similarity. Word pairs either rhymed and looked alike, rhymed but did not look alike, looked alike but did not rhyme, or did not rhyme and did not look alike. In Experiment 1 under rhyme matching, reaction time (RT) was markedly increased whenever there was a conflict between orthographic and phonological cues.

Is handwriting posture associated with differences in motor control? An analysis of asymmetries in the readiness potential.

Levy and Reid's [1] hypothesis that persons who write using the inverted posture have ipsilateral control of distal limb movements, particularly those involved in handwriting, was tested in three experiments in which asymmetries in the readiness potential (RP) were measured. In the first experiment, each subject executed a self-paced repetitive squeeze. Contralaterally larger RPs were recorded from all subjects, irrespective to handwriting posture.

A metric for thought: a comparison of P300 latency and reaction time.

We confirm that the latency of the P300 component of the human event-related potential is determined by processes involved in stimulus evaluation and categorization and is relatively independent of response selection and execution. Stimulus discriminability and stimulus-response compatibility were manipulated independently in an "additive-factors" design. Choice reaction time and P300 latency were obtained simultaneously for each trial.

Airway closure and closing pressure during mechanical ventilation.

Six subjects without clinical evidence of lung disease were investigated for airway closure and airway closing pressure before and during fentanyl-thiopentone anesthesia with mechanical ventilation. Airway closure was measured by single breath and FRC by multiple breath nitrogen washout. Airway closing pressure was taken to be the transpulmonary pressure at which airway closure commenced.

Arterial oxygenation during artificial ventilation. The effect of airway closure and of its prevention by positive end-expiratory pressure.

Airway closure and arterial blood gases were measured in 11 healthy subjects both before and during anaesthesia with artificial ventilation, prior to routine surgery. The functional residual capacity was then increased by positive end-expiratory pressure (PEEP), so that ventilation took place at a lung volume where no airway closure was present, and the effect on arterial oxygenation was again investigated. A significant increase in alveolar-arterial oxygen gradient occurred in the group of seven patients in whom airway closure within a tidal breath could be demonstrated during anaesthesia, but there was no significant change in the four patients in whom airway closure could not be demonstrated.

Sympathetic blocks.

The results of permanent chemical block of the lumbar symmpathetic chain in patients with inoperable vascular conditions, treated during the three-year period 1973--1975 is presented. The results show that, when unsuitable patients have been rejected by their poor response to continuous local aneasthetic blocks, good results with permanent phenol blocks are attainable. These are mainly in patients whose presenting symptom is pain at rest.

A dental splint for use during peroral endoscopy.

Damage to teeth is a well known complication of peroral endoscopy. A case is described in which potentially fatal complications of such damage occurred. This spurred on the development of a dental splint as an aid in the prevention of such damage.