Linking the impact of aging on visual short-term memory capacity with changes in the structural connectivity of posterior thalamus to occipital cortices

• Main Authors: Aurore Menegaux, Felix J.B. Bäuerlein, Aliki Vania, Natan Napiorkowski, Julia Neitzel, Adriana L. Ruiz-Rizzo, Hermann J. Müller, Christian Sorg, Kathrin Finke
• Format: Article
• Language: English
• Published: Elsevier 2020-03-01
• Series: NeuroImage
• Subjects: Aging; Diffusion tensor imaging; Neural theory of visual attention; Posterior thalamus; Visual short-term memory capacity
• Online Access: http://www.sciencedirect.com/science/article/pii/S1053811919310316

Aging impacts both visual short-term memory (vSTM) capacity and thalamo-cortical connectivity. According to the Neural Theory of Visual Attention, vSTM depends on the structural connectivity between posterior thalamus and visual occipital cortices (PT-OC). We tested whether aging modifies the association between vSTM capacity and PT-OC structural connectivity. To do so, 66 individuals aged 20–77 years were assessed by diffusion-weighted imaging used for probabilistic tractography and performed a psychophysical whole-report task of briefly presented letter arrays, from which vSTM capacity estimates were derived. We found reduced vSTM capacity, and aberrant PT-OC connection probability in aging. Critically, age modified the relationship between vSTM capacity and PT-OC connection probability: in younger adults, vSTM capacity was negatively correlated with PT-OC connection probability while in older adults, this association was positive. Furthermore, age modified the microstructure of PT-OC tracts suggesting that the inversion of the association between PT-OC connection probability and vSTM capacity with aging might reflect age-related changes in white-matter properties. Accordingly, our results demonstrate that age-related differences in vSTM capacity links with the microstructure and connectivity of PT-OC tracts.