The influence of stroke on visual gestalt operations.

The hypothesis that the right hemisphere is specialized for "gestalt" perception was examined by testing stroke and control subjects in a "retrieval cuing" task which is an especially promising method for assessing integrative, brain activities. The results of the study indicate that the gestalt operations are modified by damage to either the right or left hemisphere. Stroke patients seemed to have difficulty inhibiting simple, organizing cue properties, and were especially sensitive to the influence of symmetry. The deficit might best be described as a "Gestaltbindung"--loss of ability to inhibit irrelevant or conflicting gestalts so that the form properties could be thoroughly examined and compared to material being held in memory.