From birth onwards, auditory stimulation directs and intensifies visual orientation behaviour. In deaf children, by definition, auditory perception cannot take place and cannot, therefore, make a contribution to visual orientation to objects approaching from outside the initial field of view. In experiment 1, a difference in catching ability is demonstrated between deaf and hearing children (10-13 years of age) when the ball approached from the periphery or from outside the field of view. No differences in catching ability between the two groups occurred when the ball approached from within the field of view. A second experiment was conducted in order to determine if differences in catching ability between deaf and hearing children could be attributed to execution of slow orientating movements and/or slow reaction time as a result of the auditory loss. The deaf children showed slower reaction times. No differences were found in movement times between deaf and hearing children. Overall, the findings suggest that a lack of auditory stimulation during development can lead to deficiencies in the coordination of actions such as catching which are both spatially and temporally constrained.

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The transfer effects of scanning training of right-brain-damaged stroke patients with visual inattention have been studied. Five patients were treated according to a B-C-B-D design. The first B phase lasted for 2, 4, or 6 weeks, whereas the other intervention phases had a fixed duration of 2 weeks. During all phases physical therapy was given. Additionally, occupational therapy was applied during the B phases, training on a scanning apparatus during the C phase, and training on reading tasks during the D phase. At least three times in each intervention phase, performance was measured using a computerized visual scanning test, a line bisection test, and a letter cancellation test. In addition, wheelchair navigation was assessed. For four out of the five patients a significant positive effect of visual scanning training on visual scanning behaviour was found. This effect, however, appeared to be restricted to the task which was specifically trained. Over the group as a whole no evidence could be found for any transfer of visual scanning training effects to the domain of gross motor skills.

The localisation time of visual targets within and beyond the field of view and the relative timing of the onsets of eye and head movements were examined in deaf and hearing children of two age groups: 5-7 years and 10-12 years. Compared to their hearing peers, the deaf children showed more often a mode of eye-head coordination in which the head leads the eye. The discrepancy between the onsets of eye and head movements were greater for the younger than for the older groups. Furthermore, the deaf children took more time than the hearing children to localise the targets; especially the young deaf differed from their hearing contemporaries. These findings support the view that during development the differences in visual search between deaf and hearing children decrease. The results are discussed in the context of a distinction between representational and sensorimotor control of eye-head responses.

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