Gang Luo

Junxian He, Shrinivas Pundlik, Gang Luo

Objective: Micro-navigation poses challenges for blind and visually impaired individuals. They often need to ask for sighted assistance. We explored the feasibility of utilizing ChatGPT as a virtual assistant to provide navigation directions. Methods: We created a test set of outdoor and indoor micro-navigation scenarios consisting of 113 scene images and their human-generated text descriptions. A total of 412 way-finding queries and their expected responses were compiled based on the scenarios. Not all queries are answerable based on the information available in the scene image. "I do not know"response was expected for unanswerable queries, which served as negative cases. High level orientation responses were expected, and step-by-step guidance was not required. ChatGPT 4o was evaluated based on sensitivity (SEN) and specificity (SPE) under different conditions. Results: The default ChatGPT 4o, with scene images as inputs, resulted in SEN and SPE values of 64.8% and 75.9%, respectively. Instruction on how to respond to unanswerable questions did not improve SEN substantially but SPE increased by around 14 percentage points. SEN and SPE both improved substantially, by about 17 and 16 percentage points on average respectively, when human written descriptions of the scenes were provided as input instead of images. Providing further prompt instructions to the assistants when the input was text description did not substantially change the SEN and SPE values. Conclusion: Current native ChatGPT 4o is still unable to provide correct micro-navigation guidance in some cases, probably because its scene understanding is not optimized for navigation purposes. If multi-modal chatbots could interpret scenes with a level of clarity comparable to humans, and also guided by appropriate prompts, they may have the potential to provide assistance to visually impaired for micro-navigation.

Yichen Gao, Menghan Hu, Gang Luo

Providing haptic feedback via smartphone touch screen may potentially offer blind people a capability to understand graphs. This study investigated the discrimination performance of haptic gratings in different frequencies, in both visually impaired (VI) and sighted (S) individuals. 6 VI participants and 10 S participants took part in two experiments designed to compare their ability to interpret grating images with a finger swiping across a smartphone touchscreen without vision. The swipe gesture activates phone vibration temporally synchronized with the black stripes. Their tasks were: (1) determining whether a grating pattern is presented on the touchscreen, (2) comparing two different grating frequencies and determining the wider one. Results demonstrated that the VI group exhibited superior tactile sensitivity compared to the S group, as evidenced by their significantly better performance in Experiment 1 (accuracy of 99.15\% vs. 84.5\%). Experiment 2 revealed that the peak performance of VI participants was approximately around 0.270 cycles per mm (83.3\% accuracy), a frequency very similar to Braille dot spacing, while S group peaked around 0.963 cycles per mm (70\% accuracy). The findings suggest that tactile stimulation coded with grating patterns could be potentially used to present interpretable graph for the visually impaired. Such an approach could offer a value to research in human-computer interaction and sensory adaptation.