Improving spatial working memory in blind and sighted youngsters using programmable tactile displays.

OBJECTIVE: To investigate whether training with tactile matrices displayed with a programmable tactile display improves recalling performance of spatial images in blind, low-vision and sighted youngsters. To code and understand the behavioral underpinnings of learning two-dimensional tactile dispositions, in terms of spontaneous exploration strategies. METHODS: Three groups of blind, low-vision and sighted youngsters between 6 and 18 years old performed four training sessions with a weekly schedule in which they were asked to memorize single or double spatial layouts, featured as two-dimensional matrices. RESULTS: Results showed that all groups of participants significantly improved their recall performance compared to the first session baseline in the single-matrix task. No statistical difference in performance between groups emerged in this task. Instead, the learning effect in visually impaired participants is reduced in the double-matrix task, whereas it is still robust in blindfolded sighted controls. We also coded tactile exploration strategies in both tasks and their correlation with performance. Sighted youngsters, in particular, favored a proprioceptive exploration strategy. Finally, performance in the double-matrix task negatively correlated with using one hand and positively correlated with a proprioceptive strategy. CONCLUSION: The results of our study indicate that blind persons do not easily process two separate spatial layouts. However, rehabilitation programs promoting bi-manual and proprioceptive approaches to tactile exploration might help improve spatial abilities. Finally, programmable tactile displays are an effective way to make spatial and graphical configurations accessible to visually impaired youngsters and they can be profitably exploited in rehabilitation.

On my right or on your left? Spontaneous spatial perspective taking in blind people.

Spatial perspective taking is a human ability that permits to assume another person's spatial viewpoint. Data show that spatial perspective taking might arise even spontaneously by the mere presence of another person in the environment. We investigated whether this phenomenon is observable also in blind people. Blind and blindfolded sighted participants explored a tridimensional tactile map and memorized the localization of different landmarks. Then, after the presentation of sounds coming from three landmarks-positioned on the right, on the left, and in front-participants had to indicate the reciprocal position of the two lateral landmarks. Results showed that when the sound coming from the frontal landmark suggested the presence of a speaking (voice) or moving person (footsteps), several blind and sighted people adopted this person's perspective. These findings suggest that auditory stimuli can trigger spontaneous spatial perspective taking in sighted as well as in blind people.