Object identification in cerebral visual impairment characterized by gaze behavior and image saliency analysis.

Individuals with cerebral visual impairment (CVI) have difficulties identifying common objects, especially when presented as cartoons or abstract images. In this study, participants were shown a series of images of ten common objects, each from five possible categories ranging from abstract black & white line drawings to color photographs. Fifty individuals with CVI and 50 neurotypical controls verbally identified each object and success rates and reaction times were collected. Visual gaze behavior was recorded using an eye tracker to quantify the extent of visual search area explored and number of fixations. A receiver operating characteristic (ROC) analysis was also carried out to compare the degree of alignment between the distribution of individual eye gaze patterns and image saliency features computed by the graph-based visual saliency (GBVS) model. Compared to controls, CVI participants showed significantly lower success rates and longer reaction times when identifying objects. In the CVI group, success rate improved moving from abstract black & white images to color photographs, suggesting that object form (as defined by outlines and contours) and color are important cues for correct identification. Eye tracking data revealed that the CVI group showed significantly greater visual search areas and number of fixations per image, and the distribution of eye gaze patterns in the CVI group was less aligned with the high saliency features of the image compared to controls. These results have important implications in helping to understand the complex profile of visual perceptual difficulties associated with CVI.

A Questionnaire Assessing What Teachers of the Visually Impaired Know About Cortical/Cerebral Vision Impairment.

Cortical/cerebral visual impairment (CVI) is now the main cause of visual impairment in developed countries, yet it remains poorly understood. Four hundred and ninteen teachers of the visually impaired (TVIs) from across the United States responded to a questionnaire targeted at evaluating the preparedness of TVIs to serve their students with CVI. The TVIs were asked about their background knowledge, their abilities to assess a student with CVI, and their abilities to apply what they know to best help their students. The primary finding was that there is a perceived unmet need for TVIs to receive formal training in CVI during their certification. The results of this survey provide a foundation for future research on CVI knowledge and education among TVIs.