Showing papers in "Research report. Naval School of Aviation Medicine in 1965"

Perception of the visual horizontal in normal and labyrinthine defective subjects during prolonged rotation

Abstract: : Five normal and nine labyrinthine defective men were studied in a Slow Rotation Room which produced a change in resultant force of 20 degrees on them The men faced in the direction of rotation and at one minute intervals set a luminous line to the perceived horizontal in darkness for one hour The results for the normal men confirmed an earlier study showing no systematic change in the perception of the visual horizontal after an initial lag effect In contrast, the labyrinthine defective men showed a smaller, rapid, and then a gradual change in the perception of the visual horizontal throughout the one hour of constant rotation At the end of one hour there was no significant difference between the two groups These results are discussed in terms of a differential weighting of the synergistic information available to the two groups (Author)

Comparative effects of prolonged rotation at 10 rpm on postural equilibrium in vestibular normal and vestibular defective human subjects.

Abstract: Comparative effects of prolonged rotation at 10 rpm on postural equilibrium in vestibular normal and vestibular defective human subjects

Visual localization of the horizontal as a function of body tilt up to 90 degrees from gravitational vertical.

Abstract: : The visual horizontal was determined for three sophisticated subjects tilted laterally in 10 degrees intervals within =90 degrees from gravitational vertical. The task had adequate intratest reliability, but there were considerable interest and intrasubject quantitative variations. Visual localization as a function of body tilt, however, was qualitatively similar among all subjects and among the thirteen test sessions of each subject. Around upright there was a range (totaling 20 - 40 degrees on the average) of body positions in which the deviation was not significant from that of upright. Inclinations beyond this range caused the E-phenomenon to appear and increase bilaterally up to a maximum of about the 40 - 50 degrees position; with further inclination the deviation reversed direction and passed through the position (60 - 80 degrees) of zero deviation to grow as the A-phenomenon. Responses were bilaterally symmetrical in certain respects for each of the subjects. The variable error among all subjects followed a similar (curvilinear) function of body attitude. Repetition of test without immediate knowledge of results did not as a rule end in reduction of errors. (Author)

Symptomatology under storm conditions in the North Atlantic in control subjects and in persons with bilateral labyrinthine defects. NSAM-928.

Abstract: Ten labyrinthine defective (L-D) and twenty normal subjects were exposed to extremely severe weather conditions during a sea voyage. The effects of such a stress were complicated by a feeling of fear in al l of the normal and in some of the L-D subjects. None of the latter manifested typical symptoms of motion sickness whereas a l l of the normal subjects did. The fact that the L-D subjects did not become si:k suggests that, even in instances where motion sickness symptoms appear to be triggered by anxiety, the vestibular organs plan an essential etiological role. Unclassified Security Classification Security Classification

Residual effects of storm conditions at sea upon the postural equilibrium functioning of vestibular normal and vestibular defective human subjects

Abstract: Residual effects of storm conditions at sea upon postural equilibrium functioning of vestibular normal and vestibular defective human subjects

Evaluation of some antimotion sickness drugs on the slow rotation room (no. 1). nsam-922.

Abstract: Abstract : A series of antimotion sickness drugs was evaluated on the human centrifuge at the Navy School of Aviation Medicine. The procedures used enabled the same stimulus to be applied to the individual subjects through the series of drug tests. A combination of hyoscine and d-amphetamine was found to be the most effective preparation. Hyoscine alone was the most effective single drug followed by d-amphetamine and meclizine Prochlorperazine was slightly effective, but chlorpromazine, thiethylperazine, and trimethobenzamide were ineffective. Hyoscine alone produced pronounced drowsiness. The combination with d-amphetamine relieved this side effect but not the vertigo and dry mouth. The advantages of the human centrifuge in the testing of antimotion sickness drugs are pointed out. (Author)

Airsickness in student aviators

Abstract: : One thousand sixty-seven student Naval aviators were rated at the end of each flight during the pre-solo and basic acrobatic phase of training by the flight instructor for the presence or absence of nausea or vomiting during the flight. To be so rated, the airsickness had to be severe enough to cause inability to control the aircraft. In this manner, a profile of the patterns of airsickness was obtained on each student over the course of the primary flight training. The incidence of this type airsickness was 17.6 per cent (188 students out of 1.067). Correlations between incidents of airsickness per student and their ground school grades and flight grades were not statistically significant. There are three main periods during which the majority (79 per cent) of airsickness occurs. These are the initial three training flights, the seventh, and the first three dual acrobatic flights. These periods are closely correlated with the various and different peaks of physiologic and psychologic stresses during this phase of training and provide useful baselines for the evaluation of airsickness in student aviators.

Clinical pathological correlations in squirrel monkeys after suppression of semicircular canal function by streptomycin sulfate

Abstract: : Streptomycin sulfate was injected to eight selected squirrel monkeys in sufficient dosage to cause suppression of canal function as indicated by the threshold caloric test, emesis in the Slow Rotation Room, and ataxia. The animals were sacrificed six months after the suppression and slides for light-microscopic investigation were prepared following the standard temporal bone preparation procedure. Pathological findings were confined largely to the cristae and organ of Corti, which were both involved in almost every case. Only very slight changes were observed in the maculae in a few instances; therefore, this drug has a place in vestibular studies requiring selective suppression of canal function. The clinical tests used were not reliable indicators of the pathophysiological state of the cristae but were fairly reliable indicators of normal function of these organs. With regard to emesis in the SRR and ataxia, the essentiality of normal function of the semicircular canals has been demonstrated. No such essentiality was demonstrated for the otolith organs in the present investigation. (Author)

Some relationships between blood alcohol, positional alcohol nystagmus (pan), and postural equilibrium (ataxia). nsam-917.

Abstract: Relationships between blood alcohol, positional alcohol nystagmus, and postural equilibrium

The effects of environmental temperature changes on the EKG of the squirrel monkey /Saimiri sciureus/

Abstract: Environmental temperature effects on EKG of squirrel monkey - animal study of heart rate and T-wave amplitude

Changes in spontaneous activity as a measure of sensitivity to rotation in the white rat

Abstract: : Fifty-six unrestrained rats were individually exposed to a rotation speed between 0-18 RPM. Their activity was measured using a fourpoint scale: (0) no activity, (1) grooming and sniffing, (2) moderate running, and (3) rapid running. Amount of activity decreased as a function of rotation speed from 6 to 14 RPM, where it reached a lower limit plateau. Rate of decline within this speed range was also directly related to velocity. Postrotation activity was suppressed up to five minutes. The rats showed considerable sensitivity to Coriolis stimuli generated during constant speed of rotation. A relationship was found between duration and magnitude of stimulation. These findings are encouraging for the use of behavioral methods in studying sensitivity to motion. (Author)