Laryngographic study of phonation type and laryngeal configuration

This study's objective is to identify the vibratory phase characteristics and corresponding laryngeal configurations of a series of phonation types common in current phonetic usage. The phonation types examined are categorized auditorily following the articulatory framework established by Laver (1968, 1975, 1976, 1980), the general phonetic theory of Abercrombie (1967), and the systematic nomenclature for phonation types provided by Catford (1964). The primary phonation types in this taxonomy are compared laryngographically to determine their larynx waveform characteristics, based on the auditorily controlled performance of a single phonetically trained subject, and are described visually from laryngoscopic observation. This study is intended as a means of establishing a basis for further work in which a larger inventory of speakers of known background and a wider variety of possible phonatory combinations are examined. These preliminary comparisons suggest a set of relationships between phases of the vocal fold vibratory cycle and laryngeal configuration, expressed in terms of contrasting systems of stricture, and support a number of predictions that have been made in the literature on phonatory mechanisms.

The relation between oxygen requirement and speed in running

A. V. Hill and his co-workers (1) have emphasised that the relation existing between the average speed at which a race can be run and the distance to be covered depends mainly upon three factors: (a) the oxygen requirement of the exercise, ( b) the oxygen intake of the subject while running, and (c) the oxygen debt incurred by the subject. Their experiments have shown that the general type of relation that exists between speed and oxygen requirement is likely closely to resemble that found by Furusawa (2) in the case of standing-running. The results obtained hitherto, however, are of limited application. In the first place, their observations were made on a variety of subjects who used a track which was too small to permit of a high speed being readily obtained, and, in the second, their subjects were compelled to carry a large Douglas bag during the performance of the exercise. The conical Douglas bags used to collect the expired air during exercise weigh, complete with mouthpiece and rubber connections, about 10 lb.; in addition to their weight they are extremely cumbersome and hinder the free action of the subject to a marked degree. In order to arrive at some more definite conclusions as to the nature of this relationship, the whole question was re-examined, with the idea of obtaining accurate data, not hitherto available, on one trained subject under carefully controlled conditions.

The influence of various conditions on the time relations of tendon reflexes in the human subject

The following observations constitute a preliminary account of an investigation into the time relations of certain reflexes in the human subject. The knee-jerk was primarily selected for study. The variability of magnitude of the knee-jerk in response to equal stimuli has been commented on by the majority of observers, and, according to Seheven, such a variable response may occur even in the decerebrate animal. Whether variations of the irritability of the spinal reflex centre take place in the intact human subject there is no means of knowing, but study of the human responses has convinced us that by far the greatest factor in determining the variability of the knee-jerk is cortical activivity, and that, by taking suitable precautions, variability may be reduced to a negligible factor. In a previous publication, one of us (F. G.) has shown that these variations of the knee-jerk are secondary to alterations in the tonus of the quadriceps muscle. It was found that any stimulus of a nocuous nature, whether physical or psychical, caused an increase in the quadriceps tonus when the limb was flexed in the position in which the knee-jerk is elicitable, and that the magnitude of the knee-jerk was correspondingly increased. Similarly, pleasurable stimuli leading to an inhibition of effort were responded to by diminished quadriceps tonus and a diminished knee-jerk. It was found in our present experiments that, by using a trained subject and avoidance of all sources of psychical disturbance, it was possible to obtain responses to uniform stimuli which only rarely showed any irregularity. Neglect of the psychical factor has been the cause of the irregularity of response noted by so many observers. Uniformity of the stimulus was secured by the use of electrically released pendulums, which could be weighted to any desired extent. The relatively inefficient slow pushing stroke of the pendulum on the patellar tendon was converted into a more efficient stimulus of briefer duration by interposing a small piece of metal-covered wood, held in position by a stout springy steel rod. This anvil, for the reception and conversion of the pendulum blow, is adjusted in contact with the patellar tendon, and on the pendulum striking it the circuit of a Deprez signal is closed, and the moment of stimulation is photographed on the recording paper. The muscular response was recorded by photographing the excursions of the string of an Einthoven galvanometer, through which the muscle current of the quadriceps was led. For observation of more than one group of muscles simultaneously, a galvanometer with two strings was employed, and the muscle currents were explored by fine needle electrodes pushed into the substance of the muscle.