Pointing at targets by children with congenital and transient blindness.

The study investigated pointing at memorized targets in reachable space in congenitally blind (CB) and blindfolded sighted (BS) children (6, 8, 10 and 12 years; ten children in each group). The target locations were presented on a sagittal plane by passive positioning of the left index finger. A go signal for matching the target location with the right index finger was provided 0 or 4 s after demonstration. An age effect was found only for absolute distance errors and the surface area of pointing was smaller for the CB children. Results indicate that early visual experience and age are not predictive factors for pointing in children. The delay was an important factor at all ages and for both groups, indicating distinct spatial representations such as egocentric and allocentric frames of reference, for immediate and delayed pointing, respectively. Therefore, the CB like the BS children are able to use both ego- and allocentric frames of reference.