Poster Session C, Sunday, March 24, 5:00 – 7:00 pm, Pacific Concourse
Failing to Ignore: the declined functional connection between salience network and locus coeruleus in older adults
Tae-Ho Lee1, Sunhyung Kim2, Mara Mather3; 1Virginia Tech, 2University of North Carolina, Chapel Hill, 3University of Southern California
We examined functional connectivity between the locus coeruleus (LC) and the salience network in healthy young and older adults to investigate why people become more prone to distraction with age. Recent findings that the LC plays an important role in focusing processing on salient or goal-relevant information from incoming multiple sensory inputs (Mather et al, 2016), we hypothesized that the connection between LC and the salience network (SN) declines in older adults, and therefore the SN fails to appropriately filter out irrelevant sensory signals. To examine this possibility, we used resting-like fMRI data, in which all task-related activities were regressed out (Fair et al 2007) and performed a functional connectivity analysis based on the time-course of LC activity. Older adults showed relatively reduced functional connectivity between the LC and SN compared with younger adults. In addition, SN was more coupled with the frontoparietal executive network (FPN) compared to the default-mode network (DMN) in older adults than younger adults, even though all task-related activities were regressed out initially. Together, these findings suggest that the LC fails to stimulate SN as a function of stimulus priority, and in turn SN fails to initiate FPN-DMN switching appropriately. A chronic lack of switching to DMN during low priority events may drain older adults’ resources for attentional and executive control processes.
Topic Area: ATTENTION: Development & aging