Hongying Zhang MD, Presenter: Nothing to Disclose

Jing-Tao Wu MD, PhD, Abstract Co-Author: Nothing to Disclose

Attentional function declines with the progress of aging. Attention network or so-called task positive network presented anti-correlated temporal relationship with the default mode network (DMN) at a resting state, and the changes in the attention network in aging can be measured by temporal correlation analysis.

Two groups of healthy subjects including 18 young and 22 elder adults were performed EPI functional MRI scanning. A method of temporal correlation analysis was employed based on seed regions of DMN nodes of posterior cingulate cortex (PCC) and ventromedial prefrontal cortex (vmPFC). FMRI data preprocessing was performed with SPM5, and subsequent connectivity map analysis was performed using software package REST V1.4 . Connectivity maps were compared between groups by using two-sample t tests with a threshold adjustment method based on Monte-Carlo simulations correction at voxelwise p<0.05. The individual modulated grey matter volumes were entered as covariates to regress out the nuisance from brain volume difference between groups.

We found significant decreased attention network connectivity in the old group compared with the young group. The vmPFC negative network displayed attenuated activity mainly in midline regions(mainly containing supplementary motor area, SMA), whereas the PCC negative network demonstrated decreased activity in the regions of lateral fronto-parietal areas.

The decreased functional connectivity in attention networks in the old group may reflect impairments in intrinsic neuron-networks even without any task load or stimuli. The changes in the attentional networks in the resting state could provide neuronal substrates for the aging brain.

Our findings could help  to understand the mechanism of brain degeneration.

Zhang, H, Wu, J, Detection of Aging-related Alterations in the Attention Network at Resting State.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12020525.html