Age-Related Changes to the P3a and P3b

Abstract

Over the last 40 years, many studies have shown significant age-related changes to the amplitude, latency and topography of the P3a and P3b (Brown, Marsh, & LaRue, 1983; Fein & Turetsky, 1989; Fjell & Walhovd, 2001; Fjell & Walhovd, 2003; Fjell & Walhovd, 2004; Fjell, Walhovd, & Reinvang, 2005; Fjell & Walhovd, 2005a; Fjell & Walhovd, 2005b; Fjell, Walhovd, Fischl, & Reinvang, 2007; Fjell, Rosquist, & Walhovd, 2009; Walhovd & Fjell, 2003; Walhovd, Rosquist, & Fjell, 2008). In the current thesis we focused on examining the age-related changes to the underlying neural dynamics responsible for the age-related changes to the P3a and P3b. In chapter 2, we perform a wavelet transformation (WT) analysis of the P3a and P3b in younger and older adults to explore the age-related changes to the underlying neurocognitive processes involved in target and distractor processing. In chapter 3, we use dynamic causal modelling (DCM) to examine the network dynamics responsible for the generation of the P3a and P3b, and explore how these dynamics change during the course of healthy aging. In chapter 4, we use two commonly used graph theory metrics to quantify the age-related changes in intrinsic functional connectivity of frontoparietal regions involved the generation of the P3a and P3b.