An investigation of prism adaptation latency.
نویسندگان
چکیده
PURPOSE The latency of adaptation of the human vergence system to a change in convergence or divergence forced upon it by a prism was investigated in this pilot study. METHODS Adaptation was stimulated by a 5-s period of binocular vision through a prism of 0 delta, -8 delta, or 8 delta. Immediately thereafter and for a further period of 45 s, lateral heterophoria was monitored subjectively by an automated version of Duane's screen and parallax test. Adaptation was calculated from the phoria 40 s after the end of binocular vision. Tests were performed at 0.4 m. In the first test session, there was screening during the binocular period to test for flaws in the screening method. In the second session, there was no screening during the binocular period and phoria measurement was started without changing the power of the prism. In the third session, the prism was restored to 0 delta after the period of binocular vision. Immediately after the last 5-s test, tests were repeated with 1 s of binocular vision. The subject had excellent visual acuity, stereoacuity, and stereolatency. RESULTS The test functioned correctly and showed good repeatability. The greatest adaptation to 8 delta was 59%. This was obtained with only 1 s of binocular vision. There was adaptation to -8 delta with 5 s of binocular vision but it was obscured by adaptation to 0 delta or 8 delta which persisted from previous tests. DISCUSSION The reason why the subject's latency was not found more precisely is explained. Additional evidence is presented in support of the finding that prism adaptation can take place within 1 s (perhaps less) of binocular vision, and the persistence and dominance of adaptation to base-out prism at near is pointed out. Guidelines are proposed for the experimental measurement of prism adaptation latency.
منابع مشابه
AN INVESTIGATION OF EVENT-RELATED BRAIN POTENTIALS EVOKED BY FEEDBACK DURING PRISM ADAPTATION by
متن کامل
Prism adaptation reverses the local processing bias in patients with right temporo-parietal junction lesions.
Lesions to the right temporo-parietal cortex commonly result in hemispatial neglect. Lesions to the same area are also associated with hyperattention to local details of a scene and difficulty perceiving the global structure. This local processing bias is an important factor contributing to neglect and may contribute to the higher prevalence of the disorder following right compared with left he...
متن کاملPrism adaptation and unilateral neglect: review and analysis.
Theory and data from normal prism adaptation are applied toward understanding the ameliorating effects of prism adaptation for left unilateral neglect patients. Neglect is proposed to be, at least in part, a dysfunction in selection of the region of space appropriate for the task at hand. Normally, a task-work space is strategically sized and positioned (calibrated) around the task-relevant obj...
متن کاملNon-invasive Brain Stimulation and Prism Adaptation in Art Constructive Errors of Painting
Introduction: This study aimed to investigate the influence of neglect and the effect of Prism Adaptation (PA) combined with continuous Theta-Burst Transcranial Magnetic Stimulation (cTBS) on the art constructive errors of painting rehabilitation of stroke patients with neglect. Methods: Fourteen patients with neglect and art constructive errors of painting secondary to stroke were randomly as...
متن کاملPrism adaptation influences perception but not attention: evidence from antisaccades.
Prism adaptation has been shown to successfully alleviate symptoms of hemispatial neglect, yet the underlying mechanism is still poorly understood. In this study, the antisaccade task was used to measure the effects of prism adaptation on spatial attention in healthy participants. Results indicated that prism adaptation did not influence the saccade latencies or antisaccade errors, both strong ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Optometry and vision science : official publication of the American Academy of Optometry
دوره 71 1 شماره
صفحات -
تاریخ انتشار 1994