摘要:

The present study deals with the interaction of the visual and vestibular system with special reference to habituation. The results indicate that vestibular responses are modified by repeated uni- and bidirectional optokinetic stimulation. This transfer mechanism is more evident in test subjects after wide angle (foveo-peripheral) than after narrow angle (foveal) optokinetic stimulation. The modification of vestibular responses by means of repetitive optokinetic stimuli is characterized by an enhancement on the one side and a decline of the responses on the other, depending entirely on the nature of the optokinetic stimulus (uni- or bidirectional, foveal or foveo-peripheral). There is some evidence to suggest that these phenomena are habituation transfer mechanisms. They seem to subserve the improvement of the gain of the vestibulo-ocular reflex. They help the vestibular system to improve the assessment of self-rotation within the environment and to impede the development of visual-vestibular conflicts.

ISSN:0301-1569    

DOI:10.1159/000275373

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

Horizontal and vertical optokinetic nystagmus (OKN) and optokinetic after-nystagmus (OKAN) of squirrel monkeys were compared with those of rabbits, cats and humans that were previously described. Squirrel monkeys showed similar findings to cats, in which vertical optokinetic nystagmus (VOKN) is not as well elicited as horizontal optokinetic nystagmus (HOKN) and down-pursuit OKN is poorer than up-pursuit OKN. As to the reasons that bring about different responses of OKN and OKAN (and vestibular nystagmus) in different planes, we speculated two possibilities: compensatory activation of horizontal eye movement for narrowed visual field accompanied by frontally positioned eyes, and the gravity that restricts and modifies posture and locomotion. Directional difference of VOKN may be caused by a physiological mechanism that makes visual fixation not susceptible to downward movement of the ground surface during forward locomotion.

ISSN:0301-1569    

DOI:10.1159/000275374

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

The frequency spectrum of the center of gravity in normal subjects while standing was recorded by using a platform-strain gauge system and a digital computer. Individual differences of the spectral patterns resulted in the classification of three types. Averaged divisional frequency of each type was calculated in the range below 1 Hz in which the main change between the values with eyes open and those with eyes closed appeared as the frequency shift.

ISSN:0301-1569    

DOI:10.1159/000275375

出版商:S. Karger AG    

年代:1977

数据来源: Karger

摘要:

A case of congenital bilateral conductive deafness is described. Some years ago absence of the oval window was found in the left ear. Exploratory tympanotomy of the right ear revealed a large persistent stapedial artery while the facial nerve took its course from the geniculate ganglion straight down across the promontory anteriorly of the stapedial artery.

ISSN:0301-1569    

DOI:10.1159/000275376

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000275377

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000275378

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000275379

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000275380

出版商:S. Karger AG    

年代:1977

数据来源: Karger

ISSN:0301-1569    

DOI:10.1159/000275473

出版商:S. Karger AG    

年代:1977

数据来源: Karger