Figure 3
taken from Experiment 1 (left). In addition, they were also significantly faster in providing an answer when identifying newly compared to previously learned faces (right). In figures (A–G), error bars represent standard deviation. In figures (C–G), **p < 0.005, while *p < 0.05.
Auditory face identification by congenitally blind adults. Part I: Interim exploratory testing of face training progress (after 6 h of training): (A) participants were requested to answer yes/no questions on the trained faces regarding facial features (e.g., does this character have blue eyes?) to test their ability to extract meaningful information regarding facial features. Results show that participants could correctly identify facial features, especially larger features. In addition, participants were also asked to name once each trained character, and were successful in doing so. (B) To further assure participants’ were able to detect colorful features within the complicated soundscapes, we changed some features of the trained faces (e.g., eye-colors, hair color etc.). Congenitally blind participants were relatively accurate to detect the presence of a change, but were less accurate when asked to localize the change (i.e., to identify the modified face feature) and to identify the changed color. Part II: Face identification tests following 12 h of training: (C) Participants were tested on face-shape identification of the 6 trained characters. Results show that they were able to correctly identify face-shapes with high accuracy, which was significantly higher than chance level (left bar graph). In addition, they were able to provide an answer within 2 soundscape’ repetitions (right bar graph). (D) Participants were able to successfully discriminate upright (trained) from inverted (untrained) faces with an accuracy significantly above chance level (left bar graph). In addition, we also show that it took them less than 2 soundscape’s repetition to provide an answer (right bar graph). E. Participants were asked to identify face-shapes in their upright (trained) and inverted (untrained) orientation, which resulted in a completely different soundscape. Results show that participants were able to identify untrained inverted faces with an accuracy that was significantly higher than chance level, but significantly lower than their accuracy in identifying the faces when presented in the upright and trained orientation. Part III: Face identification of a new cohort of 6 characters after 2 h of additional training: (F) Participants were requested to differentiate the previously trained faces from those belonging to the new cohort, before and after a 2-h training session. Results show that participants were able to do it with an accuracy significantly above chance level, both before and after the 2-h training (left bar graph). In addition, both before and after training, they managed to provide an answer within 2 soundscape’s repetition (right bar graph). G. Following the 2-h training session, participants were successful at identifying newly-trained faces with higher accuracy than chance. They were significantly more accurate in the identification of newly compared to previously learned faces -accuracy level
