Normative data on Benton Visual Form Discrimination Test for older adults and impaired scores in Clinical Dementia Rating 0.5 participants: Community-based study. The Osaki-Tajiri Project

The Benton Visual Form Discrimination test (VFD) is one of the non-verbal tests to assess the capacity for complex visual form discrimination. The purposes of the present study were to investigate the effects of age and education level of the VFD in healthy elderly subjects, rigorously excluding participants with Clinical Dementia Rating (CDR) 0.5, and the characteristics of VFD patterns in CDR 0.5 participants. The 597 participants included CDR 0 (healthy elderly, n = 405), CDR 0.5 (mild cognitive impairment, n = 161), and CDR 1 and 2 (dementia, n = 31). The VFD, Digit Forwards, Digit Backwards and Rey-Osterrieth Complex Figure Test (RCFT) copying were used for neuropsychological assessment. There were significant effects of age and education level on the VFD in healthy participants, and the CDR 0.5 group had a lower score on the VFD than the healthy group. Low performance on the VFD was associated with Digit Backward and RCFT copying in both healthy and CDR 0.5 participants. CDR 0.5 participants exhibit deficits of visual form discrimination related to attention, visual construction and organization.