Feature Binding Deficits in Subjective Cognitive Decline and in Mild Cognitive Impairment

Background: Feature binding is a sensitive and specific cognitive marker for Alzheimer's disease (AD). Subjective cognitive decline (SCD) and mild cognitive impairment (MCI) are clinical categories associated with an increased risk for AD.

Objective: To investigate whether the SCD and MCI group are impaired with regard to feature binding.

Methods: The feature binding test was administered to memory clinic patients with either SCD (n = 19, mean MMSE: 29.2) or with MCI (n = 23, mean MMSE: 26.5), and to a group of healthy controls (HC, n = 23, mean MMSE: 29.0). Participants were assessed with the CERAD Plus neuropsychological test battery. Cognitive performance of the three groups was compared by ANCOVA with age, gender and education as covariates and planned contrasts.

Results: Groups differed in the binding condition. Planned contrasts showed significant differences in adjusted means between HC and SCD (p = 0.003), as well as between HC and MCI (p < 0.0001).

Discussion: The feature binding task detects subtle cognitive impairments in participants with SCD, who are unimpaired in traditional neuropsychological testing. This corroborates the use of feature binding tests in preclinical AD studies and suggests that specific cognitive deficits can be found in SCD. Future studies incorporating AD biomarkers and longitudinal follow-up are needed to further establish the clinical utility of feature binding.