However, there is significant variability among older adults with regard to this relationship, with some groups finding no evidence of an association (see for review). Īdditionally, some previous work using various neuroimaging methodologies (e.g., voxel-based morphometry) suggests positive associations between hippocampal size and memory performance, including in patients with AD. In general, left hemisphere structures (including left hippocampus) are implicated in verbal memory processing, while right hemisphere structures (including right hippocampus) support non-verbal/spatial memory. Lesion and functional neuroimaging studies have found that memory function is lateralized based on material type (see for review). Material-specific lateralization of brain function is a classic neurological and neuropsychological finding. Specifically, MTL atrophy and associated episodic memory impairment are hallmark features of AD, and both progressively decline over the course of the disease. Medial temporal lobe (MTL) structures (e.g., hippocampus) are integral to the formation of new memories and are centrally related to development of Alzheimer’s disease (AD). Non-verbal memory measures also may have higher diagnostic value, particularly in individuals at elevated risk for Alzheimer’s disease.

Conclusionsįindings support the link between episodic memory and hippocampal volumes in a memory clinic population. Additionally, analyses of the aMCI group showed trend-level evidence of material-specific lateralization, such that retention of verbal information was positively associated with left hippocampal volume, whereas learning curve and retention of non-verbal information was positively associated with right hippocampal volume. Amnestic Mild Cognitive Impairment (aMCI) participants showed specific positive associations between BVMT-R performance and hippocampal volumes bilaterally. Positive associations were identified between bilateral hippocampal volumes and both memory measures, and BVMT-R learning slope was more strongly positively associated with hippocampal volumes than HVLT-R learning slope. Correlational analyses were performed, and analyses on clinical subgroups (i.e., amnestic Mild Cognitive Impairment, non-amnestic Mild Cognitive Impairment, probable Alzheimer’s disease, intact memory) were conducted. Participants ( n = 226) underwent structural magnetic resonance imaging and tests of verbal (Hopkins Verbal Learning Test-Revised, HVLT-R) and non-verbal (Brief Visuospatial Memory Test-Revised, BVMT-R) memory. We examined these relationships in a memory clinic population. Better characterization of the relationship between episodic memory and hippocampal volumes is crucial in early detection of neurodegenerative disease.

Verbal memory test human benchmark