The effectiveness of a motion sickness counselling programme.

Unselected volunteers were offered a course of instruction in using the cognitive-behavioural approach to helping individuals tolerate the deleterious effects of different motion environments. In order to evaluate that programme, 11 of the participants volunteered to counsel independently individuals who were prone to motion sickness, using cognitive-behavioural training which included reinforcement by visually induced apparent motion. The subjects were pre- and post-tested by an independent observer using tolerance and motion response as the dependent variables. These test scores were compared to previous data obtained with subjects who had received counselling from an experienced counsellor, or had received no such counselling. The results indicated that the newly trained counsellors' subjects showed significant pre- to post-test tolerance to the motion stimulus, although they did not benefit as much as subjects trained by the experienced counsellor. However, in terms of post-test symptomatology and magnitude estimates of motion sickness, the trainees' subjects exhibited as much benefit as did those of the experienced counsellor. These data are taken as strong support for the feasibility of training counsellors to employ this method of alleviating motion sickness.

Cognitive-behavioral management of motion sickness.

This monograph is intended to provide health professionals with information on a cognitive-behavioral technique which was developed to teach individuals who are prone to motion sickness to better cope with motion environments. It includes an overview of motion sickness, describing the signs and symptoms, etiology and incidence of this malady. Prevention and treatment are then reviewed, including both pharmacological and non-pharmacological therapies. The historical background on the cognitive-behavioral technique is then discussed. This is followed by a review of supporting experimental work, and an account of how such counselling should be carried out. Finally, a number of current military desensitization programs are compared and contrasted with cognitive-behavioral therapy.

The effects of perceived motion on sound-source lateralization.

Lateralization of dichotic click pairs differing in time of onset was studied under conditions of angular acceleration, optokinetic stimulation, and gaze fixation. Data obtained from 20 subjects with normal hearing indicate poorer left-right judgment performance for small time differences, as well as shifts in subjective simultaneity, for all experimental conditions relative to control conditions. In addition, response times increased for the experimental conditions. The results suggest that real or apparent motion may affect an individual's ability to process one of the major cues for sound-source localization--binaural time difference--under conditions similar to those encountered in vehicular motion.

The transfer of adaptation between actual and simulated rotary stimulation.

It is well known that continued exposure to motion environments leads to adaptation, but it is not clear whether such changes are specific to the particular type of motion experienced. The present investigation sought to evaluate the extent of transfer between real motion and visually-induced apparent motion. In addition, the direction of motion was varied and these two factors, mode of exposure and direction of rotation, were examined in a cross-adaptational design. Thirty-two subjects were pre- and posttested on measures of disorientation after active bodily rotation and visually-induced self-vection. Two groups received ten consecutive trials of active bodily rotation (clockwise or counter-clockwise) for 4 consecutive days. Two other groups received ten consecutive trials of visually-induced self-vection (clockwise or counter-clockwise) in a rotating drum for 4 consecutive days. During the exposure phase, dizziness and self-vection increased over trials for the groups exposed to the drum, while dizziness remained unchanged over trials for the groups exposed to bodily rotation. Repeated exposure to bodily rotation resulted in improved walking performance over trials and days. Subjects exposed to bodily rotation exhibited increased tolerance to visually-induced self-vection; however, exposure to visually-induced self-vection did not result in greater tolerance to bodily rotation. No support for directional specificity was evident.

Generalization of tolerance to motion environments.

The aim of the present investigation was to determine to what extent training tolerance to one motion stimulus would generalize other motion experiences. Twenty subjects prone to motion sickness were selected and assigned to one of four groups after pretesting in a Dichgans and Brandt drum to determine their susceptibility to visually-induced apparent motion. They were also pretested with a VDT display of an expanding surface, and on a revolving/tilting chair. Subjects were assigned to one of the four groups by matching their mean tolerance to visually-induced motion. Subjects in the first group served as controls and received only cognitive counseling regarding their ability to tolerate motion environments. Subjects in the other groups received the same counseling coupled with incremental exposures to the drum, chair, or VDT, respectively. Posttests on each apparatus revealed that the treatments involving the chair and the drum provided specific increases in tolerance to the device used during treatment, and that the treatment involving the chair provided a generalized tolerance to visually-induced motion. These results support the notion that there are both specific and general components in learning to tolerate motion environments.

Reduction of visually-induced motion sickness elicited by changes in illumination wavelength.

This experiment was undertaken to assess the degree of stimulus generalization in visually-induced motion sickness. Sixteen subjects participated in six sessions in which they were exposed to a rotating field of vertical stripes for five 4-min trials. This stimulus elicited the perception of self-vection. In the first three sessions, the stripes were illuminated by one monochromatic light (red or green) and in the last three sessions, the stripes were illuminated by the other monochromatic light. Magnitude estimates of motion sickness increased significantly within sessions, but the rate at which this measure increased was significantly diminished across trials in the last three-session block. Magnitude estimates of vection increased within sessions and decreased across sessions, but did not increase with color change. These results can be explained in terms of a model of stimulus generalization and have implications for the reduction of motion sickness in applied settings.

An evaluation of cognitive-behavioral therapy for training resistance to visually-induced motion sickness.

This investigation examined the techniques for reducing visually-induced motion sickness. On the basis of their responses to a motion sickness history questionnaire, 32 subjects were selected and assigned to 1 of 4 groups such that the groups were matched on the basis of their ability to tolerate visually-induced apparent motion (VM). One group received 10 sessions of desensitization training only (DT); a second group received 10 sessions of cognitive therapy only (CT); a third group received 10 sessions of combined desensitization and cognitive therapy treatment (CG); and a fourth group received no treatment (C). (There are many speculations about why and how an individual's response changes with repeated stimulation. We have arbitrarily selected the term desensitization to connote the decrease in sensitivity over time with repeated exposures). The results indicated that only the groups which received cognitive therapy (i.e., CT and CG) exhibited significant increases in tolerance to VM when pretreatment measures were compared to posttreatment measures. No significant differences in pre- vs. posttreatment measures were observed in the desensitization only or control groups (i.e., DT and C). A similar pattern of results was obtained with the symptomatology data.

Measures of auditory evoked potentials during optokinetic stimulation.

In this investigation auditory brainstem responses (ABR) elicited by click stimuli were recorded before, during, and after optokinetic stimulation in subjects that were (N = 10) or were not (N = 10) prone to visually induced motion sickness. The latency of Wave I, and the I-III and I-V interwave intervals were measured. A significant increase in the I-III interwave interval occurred only during optokinetic stimulation. Neither the Wave I latency nor the interwave interval differed with respect to subject groups and this factor did not interact with any other variables. These results suggest that optokinetic stimulation may alter neural activity in the region of the superior olivary complex, a structure known to be important in sound-source localization.

A comparison of two methods of training resistance to visually-induced motion sickness.

This report concerns the use of two methods of training subjects to tolerate visually-induced motion sickness (VMS). Sixteen subjects were selected on the basis of their response to a motion sickness history questionnaire and assigned to one of four groups on the basis of their ability to tolerate visually-induced motion (VM). One group received 10 sessions of confidence building and desensitization training (BT); a second group received 10 sessions of EMG and temperature biofeedback (FB); a third group received 10 sessions of BT and 10 sessions of FB (BTFB); and a fourth group received no treatment (C). The results indicated that the BT and BTFB groups exhibited significant increases in tolerance to VM when pretreatment measures were compared to posttreatment measures, while no significant differences in pre-post measures were observed in the FB or C groups. A similar pattern emerged from the symptomatology data.