Journal of Vestibular Research - Volume 8, issue 2

Article Type: Other

DOI: 10.3233/VES-1998-8208

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. I-I, 1998

Authors: Quinn, Kevin J.

Article Type: Review Article

Abstract: Adaptation of the vestibulo-ocular reflex (VOR) is one of the principal models for studying motor learning in the mammalian eNS. However, there has been no previous comprehensive attempt to understand the behavioral characteristics of VOR adaptation in terms of traditional psychological learning theory. To accomplish this objective, the effectiveness of vestibular-evoked responses in serving as the conditioned or unconditioned stimulus in classical conditioning paradigms is first reviewed. Then, the various procedures for eliciting VOR adaptation are reviewed from the perspective of their similarity to standard classical conditioning protocols. A systematic analysis of Western and Russian literature yielded a relatively small …number of studies that explicitly used vestibular reflexes in classical conditioning paradigms, and they report a wide range in success. Potential explanations for these diverse findings are discussed. A comprehensive categorization of the behavioral parallels between VOR adaptation and classical conditioning is then presented. Viewing VOR adaptation as a form of classical conditioning is a useful heuristic device and leads directly to the description of further behavioral experiments that could throw additional light on general mechanisms for inducing neural plasticity. Such an exercise is of benefit in order to further understand the common framework which might exist between VOR adaptation and other models of motor learning (for example, rabbit eye blink conditioning). Show more

Keywords: classical conditioning, VOR, adaptation, vestibulo-ocular reflex, eye blink, nictitating membrane

DOI: 10.3233/VES-1998-8201

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 117-133, 1998

Authors: Coats, Alfred C. | Norfleet, William T.

Article Type: Research Article

Abstract: We evaluated a new model of motion sickness—an enclosure decorated with visual cues to upright which was immersed either inverted or “front”-wall down, in Johnson Space Center's Weightless Environment Training Facility (WETF) pool. This “WETF False Vertical Room” (WFVR) was tested with 19 male and 3 female SCUBA diver subjects, aged 23 to 57, who alternately set clocks mounted near the room's 8 corners and made exaggerated pitch head movements. We found that (1) the WFVR test runs produced motion sickness symptoms in 56% and 36% of subjects in the room-inverted and room-front-down positions, respectively. (2) Pitch head movements were …the most provocative acts, followed closely by setting the clocks—particularly when a clock face filled the visual field. (3) When measured with a self-ranking questionnaire, terrestrial motion sickness susceptibility correlated strongly (P < 0.005) with WFVR sickness susceptibility. (4) Standing instability, measured with a modified Fregly–Graybiel floor battery, also correlated strongly (P < 0.005) with WFVR sickness susceptibility. This result may reflect a relationship between visual dominance and WFVR sickness. (5) A control study demonstrated that the inverted and front-down positions produced WFVR sickness, but the upright position did not, and that adaptation may have occurred in some subjects with repeated exposure. The WFVR could become a useful terrestrial model of space motion sickness (SMS) because it duplicates the nature of the gravity-dependent sensory conflicts created by micro-gravity (visual and otolith inputs conflict while somatosensory gravity cues are minimized), and it also duplicates the nature of the provocative stimulus (sensory environment “rule change” versus application of motion to passive subject) more closely than any other proposed terrestrial SMS model. Also, unlike any other proposed terrestrial SMS model, the WFVR incorporates whole-body movement in all three spatial dimensions. However, the WFVR's sensory environment differs from that created by spaceflight in several respects, including the presence of frictional drag on limb movement, magnification at the face-mask-water interface, greater otolith conflict, exhaled bubbles, and the presence of some gravity-dependent somatosensory inputs. Show more

Keywords: motion sickness, space motion sickness, spatial orientation, standing stability, sensory conflict

DOI: 10.3233/VES-1998-8202

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 135-149, 1998

Authors: Darlington, Cynthia L. | Smith, Paul F.

Article Type: Research Article

Abstract: This paper reports further evidence that gender is a significant factor in the experience of circularvection (CV), the illusion of self-rotation. Using optokinetic drum velocities between 24° and 92°/s, latency to experience Stage 2 or Stage 3 CV was measured. Males exhibited significantly longer CV latencies than females (P < 0.0001), although the difference was greater for Stage 3 CV than for Stage 2 CV. This result suggests that the potential influence of gender must be carefully controlled in visual–vestibular interaction experiments.

Keywords: circularvection, gender, optokinetic, visual–vestibular interaction

DOI: 10.3233/VES-1998-8203

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 151-153, 1998

Authors: Helmchen, C. | Jäger, L. | Büttner, U. | Reiser, M. | Brandt, T.

Article Type: Research Article

Abstract: In the chronic-relapsing form of Cogan's syndrome, it can be difficult to evaluate the activity of the disease. In contrast to the initial stage, routine diagnostic techniques sometimes fail to indicate progression in the chronic stage. To determine whether high-resolution magnetic resonance imaging (HR-MRI) can be used to differentiate between active and inactive stages, we examined three patients with Cogan's syndrome (one during an acute relapse, two with chronic audiovestibular deficits), all of whom had antibodies to inner ear tissue (cochlea, vestibular labyrinth). Unenhanced T1-, T2, gadolinium-enhanced T1-weighted, and three-dimensional constructive interference in steady stage (CISS) images were used. Abnormal …MRI signals of the inner ear were related to the activity of the disease. The patient studied during an acute exacerbation showed abnormal MRI signals in the vestibule, semicircular canals, vestibular nerve, and cochlea, which disappeared after the relapse. These abnormalities included high signal in the membranous labyrinth, the vestibule, and cochlea, with enhancement on T1-weighted images, indicating gadolinium leakage through the abnormal labyrinthine membrane into the perilymphatic spaces. In contrast, the other two patients with chronic audiovestibular deficits but no clinical signs of an acute relapse, had narrowing or occlusion of semicircular canals of the cochlea on the 3D-CISS images, but no high signal lesions (T1) and no enhancement. We conclude that sequential gadolinium-enhanced MRI can identify the active stage of Cogan's syndrome. The combination of HR-MRI and antibodies to inner ear antigens are helpful in the diagnosis of acute, sequential, bilateral audiovestibular impairment of autoimmune origin. Show more

Keywords: MRI, Cogan's syndrome, inner ear antibodies, semicircular canal, vestibule, cochlea

DOI: 10.3233/VES-1998-8204

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 155-167, 1998

Authors: Suzuki, Mamoru | Kadir, Abdul | Hayashi, Naoki | Takamoto, Muneo

Article Type: Research Article

Abstract: Effect of thermal stimulus on the vestibular receptor was studied using the isolated frog semicircular canal. The posterior (PSC) and lateral semicircular canals (LSC) were placed in the horizontal plane in frog Ringer's solution. The ampullary nerve was sucked into a glass suction electrode to record compound potentials. The steel thermal probe was positioned next to the ampullary surface to give thermal stimuli. When the PSC ampulla was cooled, the spontaneous discharge markedly increased. When the PSC ampulla was warmed, the discharge decreased. When the LSC ampulla was cooled, the discharge increased in the same manner as in the PSC. …Also, warming of the LSC decreased the discharge in the same manner as in the PSC. The cupula was removed from the crista in order to eliminate the effect of volume change of the endolymph. The results were comparable to those with intact cupula in both the PSC and LSC. Cooling increased, while warming decreased the discharge. These responses are possibly due to a mechanism other than mechanical volume change, because the PSC and LSC yielded the same type of responses. Direct temperature reaction of the vestibular hair cell was suggested. Show more

Keywords: temperature, semicircular canal, hair cell, cupula

DOI: 10.3233/VES-1998-8205

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 169-173, 1998

Authors: Chen-Huang, Chiju | McCrea, Robert A.

Article Type: Short Communication

Abstract: 1. The firing behavior of seven antidromically identified ascending tract of Deiters (ATD) neurons was recorded in one alert squirrel monkey trained to pursue moving targets and to fixate visual targets at different distances from the head during whole body rotation. 2. ATD cells generated signals related to contralateral horizontal smooth pursuit eye movements and to ipsilateral angular and linear head velocity. Most ATD neurons reversed the direction of their response to head rotation when the vestibulo-ocular reflex was canceled by fixation of a head stationary target. 3. ATD unit gains in respect to linear head velocity increased dramatically (>4×) …when a near, earth stationary target (10 cm from the eyes) was fixated, compared to the response recorded during fixation of a far target (130 to 170 cm from the eyes). Since the viewing distance related changes in the responses of ATD neurons closely parallel the changes in the responses of the eyes, the ATD appears to be an important premotor pathway for producing viewing distance related changes in the gain of the vestibulo-ocular reflex. Show more

Keywords: vestibular nuclei, vergence, linear VOR, secondary vestibular neurons

DOI: 10.3233/VES-1998-8206

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 175-184, 1998

Article Type: Other

DOI: 10.3233/VES-1998-8207

Citation: Journal of Vestibular Research, vol. 8, no. 2, pp. 185-185, 1998