Visual processing of configuration-dependent spatial characteristics of shapes and patterns. A model useful in the study of the role of the departure from circularity or dispersion of shapes in human visual perception.

In this work a theoretical model was used in combination with testings on normal subjects to get more insight in the role of the departure from circularity or dispersion of the shapes in visual perception. The model was inspired by the observation that the intensity of the effect of a given level of contrast of a shape usually increases, for the same area, with the shape being better concentrated around a center. The model introduces as a measurable characteristic the degree of concentration or dispersion of a shape with respect to a center.

Voluntary multiplet discharge after the activation test for spasmophilia as an electromyographic sign of a mild form of this disease.

The electromyographic (EMG) diagnosis of spasmophilia is based on the appearance in a susceptible muscle of spontaneous burst (multiplet) discharges after an activation procedure consisting usually in 10 minutes ischemia followed by a pause of a length that varies with the author but does not exceed 5 minutes, and finally by a hyperventilation, again not exceeding 5 minutes. In investigations carried out many years ago we observed that a number of subjects with symptoms of spasmophilia showed no postischemic spontaneous bursts, but responded with bursts to voluntary contraction. In this work we present some findings leading to the conclusion that voluntary burst discharge after the activation procedure can represent a sign of spasmophilia and not a mere manifestation within normal limits.

Electrical activity induced by ischemia in the skeletal muscle of patients with spasmophilia.

The incidence of spontaneous electrical activity during ischemia was studied in normal and spasmophilic subjects with a Bronk electrode inserted in the first dorsal interosseous muscle. Subjects were of both sexes, aged 16 to 65 years. The diagnosis of spasmophilia was established electromyographically by a variant of the Alajouanine test.

Visual size analysers and Mueller-Lyer illusions.

The characteristics of the structural components inducing a length distortion were studied in Mueller-Lyer configuration and in other similar or different configurations. When placed in a more central position both ingoing and outgoing fins induced an apparent shrinkage of the shaft. It was found that a comparable effect is obtained as well with perpendicular lines and various other forms placed slightly centrally from the ends of the shaft (when placed away from the ends, an elongation is obtained).