Teng Santani, Danforth Caroline, Paternoster Nickolas, Ezeana Michael, Puri Amrita
Smith-Kettlewell Eye Research Institute, San Francisco, CA, United States.
Department of Biology, University of Central Arkansas, Conway, AR, United States.
Front Neurosci. 2024 Feb 19;18:1288635. doi: 10.3389/fnins.2024.1288635. eCollection 2024.
Active echolocation allows blind individuals to explore their surroundings via self-generated sounds, similarly to dolphins and other echolocating animals. Echolocators emit sounds, such as finger snaps or mouth clicks, and parse the returning echoes for information about their surroundings, including the location, size, and material composition of objects. Because a crucial function of perceiving objects is to enable effective interaction with them, it is important to understand the degree to which three-dimensional shape information extracted from object echoes is useful in the context of other modalities such as haptics or vision. Here, we investigated the resolution of crossmodal transfer of object-level information between acoustic echoes and other senses. First, in a delayed match-to-sample task, blind expert echolocators and sighted control participants inspected common (everyday) and novel target objects using echolocation, then distinguished the target object from a distractor using only haptic information. For blind participants, discrimination accuracy was overall above chance and similar for both common and novel objects, whereas as a group, sighted participants performed above chance for the common, but not novel objects, suggesting that some coarse object information (a) is available to both expert blind and novice sighted echolocators, (b) transfers from auditory to haptic modalities, and (c) may be facilitated by prior object familiarity and/or material differences, particularly for novice echolocators. Next, to estimate an equivalent resolution in visual terms, we briefly presented blurred images of the novel stimuli to sighted participants ( = 22), who then performed the same haptic discrimination task. We found that visuo-haptic discrimination performance approximately matched echo-haptic discrimination for a Gaussian blur kernel σ of ~2.5°. In this way, by matching visual and echo-based contributions to object discrimination, we can estimate the quality of echoacoustic information that transfers to other sensory modalities, predict theoretical bounds on perception, and inform the design of assistive techniques and technology available for blind individuals.
主动回声定位使盲人能够通过自行发出的声音探索周围环境，这与海豚和其他回声定位动物类似。回声定位者发出声音，如打响指或口腔发出的咔哒声，并解析返回的回声以获取有关周围环境的信息，包括物体的位置、大小和物质组成。由于感知物体的一个关键功能是实现与它们的有效互动，因此了解从物体回声中提取的三维形状信息在触觉或视觉等其他模态的背景下有多大用处非常重要。在这里，我们研究了物体级信息在声学回声和其他感官之间跨模态转移的分辨率。首先，在延迟匹配样本任务中，盲人专家回声定位者和有视力的对照参与者使用回声定位检查常见（日常）和新颖的目标物体，然后仅使用触觉信息将目标物体与干扰物区分开来。对于盲人参与者，辨别准确率总体上高于随机水平，并且对于常见物体和新颖物体相似，而作为一个群体，有视力的参与者对于常见物体的辨别准确率高于随机水平，但对于新颖物体则不然，这表明一些粗略的物体信息（a）对专家盲人和新手有视力的回声定位者都可用，（b）从听觉模态转移到触觉模态，并且（c）可能会因先前对物体的熟悉程度和/或物质差异而得到促进，特别是对于新手回声定位者。接下来，为了以视觉术语估计等效分辨率，我们向有视力的参与者（n = 22）简要呈现新颖刺激的模糊图像，然后他们执行相同的触觉辨别任务。我们发现，对于高斯模糊核σ约为2.5°的情况，视觉 - 触觉辨别性能大致与回声 - 触觉辨别性能匹配。通过这种方式，通过匹配视觉和基于回声的对物体辨别的贡献，我们可以估计转移到其他感官模态的回声声学信息的质量，预测感知的理论界限，并为盲人可用的辅助技术和设备的设计提供信息。
