Use of background interference procedure to assess visual retention deficits in multiple-sclerosis, psychiatric, and...

The performances of three groups of patients were compared during two conditions of interference on a visual retention task. During the noninterference condition, the psychiatric, multiple-sclerosis, and brain-damaged patients functioned at a comparable level. The introduction of a distracting background reduced the level of functioning for only the brain-damaged group. This effect remained significant for the correct score when age and postmorbid intelligence functioning were controlled. These results were interpreted as reflecting the cortical nature of the deficits in resisting the distracting influence of the background interference procedure. Serial testing was recommended for the evaluation of the multiple-sclerosis group.