Sensory Information Processing with Low Vision

描述(申请人提供)：过马路是一项复杂的、高风险的日常生活活动。行人在作出安全横过马路的适当决定时，必须判断车流中的空隙是否有足够的持续时间，使他们能够到达街道的另一边或分隔岛。行人通过处理从环境中获得的复杂感觉信息来识别可穿越的缝隙。毫无疑问，视觉信息在检测可跨越间隙的准确性和效率方面起着不可或缺的作用。然而，当视觉信息减少时，人们对其他感官信息来源的相对重要性知之甚少。在视觉信息退化的情况下，由于盲人可以安全、独立地通过街道，听觉信息可能在过马路中发挥重要作用。为了确定听觉信息是否能在视障行人过马路时补充视觉信息，首先必须建立一种可靠的、经验性的评估方法。这项研究的目的是验证接收器工作特征(ROC)曲线在评估低视力者过马路时视觉和听觉信息处理的使用。使用5分评级标准，将对正常视力、视障和失明受试者进行不同持续时间的可跨越间隙的安全评级。对于视力正常和视力受损的受试者，安全评级将在三种感官测试条件下收集：(I)视觉和听觉信息；(Ii)仅视觉信息；和(Iii)仅听觉信息。盲人受试者的安全评级将仅来自听觉信息。在法向-偏差(z-Score)坐标上构建ROC曲线将检验本研究中应用的ROC曲线是否为评估低视力过街的感觉信息处理的有效量度。比较测试条件和受试者组之间不同间隔持续时间的可识别性(d‘)将确定该度量可以测量听觉效果以及视觉感觉通道中的性能变化的范围。鉴于行人安全已被认为是一个主要的公共健康问题，拟议的研究将提供数据，以形成一个客观的基础，以发展旨在帮助视障行人过马路的培训计划、移动设备和环境变化。

DESCRIPTION (provided by applicant): Crossing a street is a complicated, high-risk activity of daily living. In making an appropriate decision of when it is safe to cross, pedestrians must judge gaps in vehicular traffic that is of sufficient duration to allow them to reach the other side of the street or a splitter island. Pedestrians identify crossable gaps by processing complex sensory information acquired from the environment. Undoubtedly, visual sensory information plays an integral role in the accuracy and efficiency of detecting crossable gaps. Little is known however, about the relative importance of other sources of sensory information when visual information is reduced. Auditory sensory information may play an important role in street crossing when visual information is degraded since blind people can successfully cross a street safely and independently. To determine if auditory sensory information augments visual sensory information in street crossing for visually impaired pedestrians, a reliable, empirical method of assessment must first be established. The proposed research has the goal of validating the use of receiver operating characteristic (ROC) curves to assess visual and auditory information processing for street crossing in people with low vision. Using a 5 point rating scale, safety ratings for crossable gaps of different durations will be measured in normally sighted, visually impaired and blind subjects. For the normally sighted and visually impaired subjects, safety ratings will be collected under 3 sensory test conditions: (i) visual and auditory information; (ii) visual information only; and (iii) auditory information only. The safety ratings of blind subjects will be from auditory information only. Constructing ROC curves on normal-deviate (z-score) coordinates will test whether or not ROC curves as applied in the proposed study is a valid metric for assessing sensory information processing for street crossing in low vision. Comparing the discriminability (d') of different gap durations between test conditions and subject groups will establish the range over which the metric can measure an auditory effect as well as changes in performance in the visual sensory channel. Given that pedestrian safety has been recognized as a major public health concern, the proposed research will provide data to form an objective base for the development of training programs, mobility devices and environmental changes designed to assist visually impaired pedestrians cross a street.