Furman Joseph M, Müller Martijn L T M, Redfern Mark S, Jennings J Richard
Department of Otolaryngology, Eye & Ear Institute Building, University of Pittsburgh School of Medicine, Suite 500, 200 Lothrop Street, 15213, Pittsburgh, PA, USA.
Exp Brain Res. 2003 Oct;152(3):383-92. doi: 10.1007/s00221-003-1560-z. Epub 2003 Aug 12.
Attention has been implicated in postural control and other tasks requiring sensory integration. The purpose of this study was to investigate the role of attention in sensory-motor processing of vestibular and combined visual-vestibular information during seated rotations using a dual-task interference approach. We hypothesized that auditory information processing would be influenced by concurrent visual-ocular, vestibulo-ocular, or combined visual-vestibulo-ocular processing. We further hypothesized that the effect would be greater in older subjects. Twenty older subjects (10 women, 10 men, 69.3+/-3.2 years) and 20 young subjects (10 women, 10 men, 23.5+/-2.9 years) were asked to perform information-processing tasks while they underwent several types of vestibular, visual-vestibular, and ocular motor paradigms. The information-processing tasks were: (1) an auditory simple reaction-time task (SRT), (2) an auditory go-no-go (disjunctive) reaction-time task (DRT), and (3) an auditory forced-choice task (CRT). The visual-vestibular-ocular motor conditions included: (1) no movement/darkness (NO), (2) no movement/fixation (FIX), (3) no movement/pursuit (P), (4) earth-vertical axis rotation (EVAR) in darkness, (5) EVAR with fixation (E-FIX), (6) off-vertical axis rotation (OVAR) in darkness, and (7) OVAR with fixation (O-FIX). Results showed that older subjects had longer reaction times for all combinations of stimulus condition and reaction-time task compared with young subjects. Compared with the NO baseline, reaction times during EVAR were longer for young and older subjects and during OVAR were longer for the young subjects. For FIX and P, the reaction times during P exceeded those during FIX and during NO for both groups. For E-FIX and O-FIX, reaction times did not differ from those during EVAR and OVAR. The interference with information processing by concurrent vestibular stimulation in the dark may be based upon cortical inhibition of auditory processes by vestibular stimulation. Eye movements induced by EVAR showed an increased phase lead during reaction-time tasks, suggesting altered vestibulo-ocular reflex (VOR) dynamics, possibly based on cerebellar-mediated changes in velocity storage. Since fixation of a head-fixed visual target did not add to the effect of rotation in the dark, a further implication of our results is that VOR-fixation while performing a concurrent information-processing task may be accomplished primarily by VOR suppression rather than by VOR cancellation.
注意力已被认为与姿势控制及其他需要感觉整合的任务有关。本研究的目的是使用双任务干扰方法，调查注意力在坐位旋转过程中对前庭及视觉 - 前庭联合信息的感觉运动处理中的作用。我们假设听觉信息处理会受到同时进行的视觉 - 眼动、前庭 - 眼动或视觉 - 前庭 - 眼动联合处理的影响。我们进一步假设这种影响在老年受试者中会更大。20名老年受试者（10名女性，10名男性，69.3±3.2岁）和20名年轻受试者（10名女性，10名男性，23.5±2.9岁）在接受几种类型的前庭、视觉 - 前庭和眼动范式时被要求执行信息处理任务。信息处理任务包括：（1）听觉简单反应时任务（SRT），（2）听觉去 - 不去（析取）反应时任务（DRT），以及（3）听觉强制选择任务（CRT）。视觉 - 前庭 - 眼动条件包括：（1）无运动/黑暗（NO），（2）无运动/注视（FIX），（3）无运动/跟踪（P），（4）黑暗中的地垂直轴旋转（EVAR），（5）有注视的EVAR（E - FIX），（6）黑暗中的离垂直轴旋转（OVAR），以及（7）有注视的OVAR（O - FIX）。结果表明，与年轻受试者相比，老年受试者在刺激条件和反应时任务的所有组合下反应时间更长。与NO基线相比，年轻和老年受试者在EVAR期间的反应时间更长，而年轻受试者在OVAR期间的反应时间更长。对于FIX和P，两组在P期间的反应时间超过了FIX期间和NO期间的反应时间。对于E - FIX和O - FIX，反应时间与EVAR和OVAR期间的反应时间没有差异。黑暗中同时进行的前庭刺激对信息处理的干扰可能基于前庭刺激对听觉过程的皮质抑制。EVAR诱发的眼动在反应时任务期间显示出相位超前增加，表明前庭眼反射（VOR）动力学改变，可能基于小脑介导的速度存储变化。由于固定头部固定的视觉目标并没有增加黑暗中旋转的影响，我们结果的进一步含义是，在执行同时进行的信息处理任务时，VOR - 注视可能主要通过VOR抑制而不是VOR抵消来完成。
