Date Published: November 8, 2017
Publisher: Public Library of Science
Author(s): Andrea R. Zammit, Ali Ezzati, Mindy J. Katz, Molly E. Zimmerman, Michael L. Lipton, Martin J. Sliwinski, Richard B. Lipton, Stephen D. Ginsberg.
In this study we investigated the role of hippocampal volume (HV) in visual memory.
Participants were a subsample of older adults (> = 70 years) from the Einstein Aging Study. Visual performance was measured using the Complex Figure (CF) copy and delayed recall tasks from the Repeatable Battery for the Assessment of Neuropsychological Status. Linear regressions were fitted to study associations between HV and visual tasks.
Participants’ (n = 113, mean age = 78.9 years) average scores on the CF copy and delayed recall were 17.4 and 11.6, respectively. CF delayed recall was associated with total (β = .031, p = 0.001) and left (β = 0.031, p = 0.001) and right HVs (β = 0.24, p = 0.012). CF delayed recall remained significantly associated with left HV even after we also included right HV (β = 0.27, p = 0.025) and the CF copy task (β = 0.30, p = 0.009) in the model. CF copy did not show any significant associations with HV.
Our results suggest that left HV contributes in retrieval of visual memory in older adults.
Medial temporal lobe structures, in particular the hippocampus, play an undisputed role in memory processes. Prior studies, investigating the role of hippocampus in memory processes, have suggested differential areas of brain activation for verbal and spatial ability, with right hippocampal volume (HV) more strongly associated with spatial memory, while left HV more storongly associated with verbal memory [1–3]. Structural MRI studies in Alzheimer’s disease (AD) research have also shown these associations [7, 8]. However, few studies have focused on the roles of visual memory in the hippocampus. There has been increasing evidence showing that measures of visual memory are key markers of hippocampal integrity , have better diagnostic value, and can discriminate individuals at various stages on the diagnostic scale (i.e. MCI, AD) [10–12].
The mean age of the sample was 78.9 years and 39.8% were male. Global cognitive function using the Blessed Information Memory Concentration  was 2.1 (SD = 2.4). Mean scores on measures of visual performance and memory using CF copy and delayed recall were 17.4 and 11.6 (SDs = 2.0 and 3.8). Table 1 summarizes the sample characteristics for the 113 participants.
In this study we explored visual performance in copy and recall tasks in non-demented older adults using the RBANS Complex Figure copy and delayed recall tasks. We showed that delayed visual memory as measured by RBANS Complex Figure delayed recall is associated with left hippocampal volume.