Generation of oculomotor images during tasks requiring visual recognition of polygons.

This paper concerns the contribution of mentally simulated ocular exploration to generation of a visual mental image. In Exp. 1, repeated exploration of the outlines of an irregular decagon allowed an incidental learning of the shape. Analyses showed subjects memorized their ocular movements rather than the polygon. In Exp. 2, exploration of a reversible figure such as a Necker cube varied in opposite directions. Then, both perspective possibilities are presented. The perspective the subjects recognized depended on the way they explored the ambiguous figure. In both experiments, during recognition the subjects recalled a visual mental image of the polygon they compared with the different polygons proposed for recognition. To interpret the data, hypotheses concerning common processes underlying both motor intention of ocular movements and generation of a visual image are suggested.

Motor dimension of visual mental image transformation processes.

This paper concerns the influence of perceptual motor skills on the transformation processes during mental visual imaging. We first administered a visual recognition task to subjects, during which they scanned and rotated visual mental images. Then, we measured motor skills in perceptual situations. The main result is that both mental scanning and mental rotation processes are quicker when they simulate a perceptual motor skill of the subject. Furthermore, mental rotation seems to be canceled when the hemisphere activated by perception has to control the behavioral response. These results suggest that visual mental images are transformed partly via motor processes.

Personality patterns of anxiety during occupational deep dives with long-term confinement in hyperbaric chamber.

Extreme environments are generally thought to be stressful situations. Occupational deep diving inflicts periods of long-term confinement in hyperbaric chambers and high-pressure exposure on divers. Such extreme environmental conditions have been demonstrated to produce acute responses of anxiety in individual divers. Although these studies have mentioned personality as a factor explaining why some divers reported an increase in ratings of anxiety, the role of personality traits still remains unclear. The present study examines the possible role of personality traits in the development of diving anxiety. Results confirm that diving anxiety remains at the individual level and relatively transient and suggest that personality factors, such as low self-control and emotional instability, that reflect an incapacity to control and express tension in an appropriate manner would play a crucial role in the occurrence of diving anxiety.

[Trypanosomiasis: determination of groups of patients from clinical and electroencephalographic data]. / Trypanosomiase: détermination de groupes de patients à partir de données cliniques et électroencéphalographiques.

Data constituted from clinical and waking electroencephalographic signs in 104 patients at meningoencephalitis stage of trypanosomiasis were treated by way of a correspondence analysis in order to determine clinical profiles. Three profiles were identified. The first one, encountered in patients with minor clinical disturbances and slightly modified waking electroencephalographic patterns is suggestive of a cerebral involvement stage onset. The second one, observed in patients with vigilance disturbances, behavioral and motor impairment, and highly abnormal EEG tracing is indicative of a more severe encephalitis stage. The third one, obvious in patients with EEG sharp waves organized in a more or less recurring fashion and accompanied by epileptic seizures is consistent with an acute cerebromeningitis.