Reduced semantic control in older adults is linked to intrinsic DMN connectivity

Publication date: Available online 3 July 2019Source: NeuropsychologiaAuthor(s): Katya Krieger-Redwood, Hao-Ting Wang, Giulia Poerio, Léa M. Martinon, Leigh M. Riby, Jonathan Smallwood, Elizabeth JefferiesAbstractAgeing provides an interesting window into semantic cognition: while younger adults generally outperform older adults on many cognitive tasks, knowledge continues to accumulate over the lifespan and consequently, the semantic store (i.e., vocabulary size) remains stable (or even improves) during healthy ageing. Semantic cognition involves the interaction of at least two components – a semantic store and control processes that interact to ensure efficient and context-relevant use of representations. Given older adults perform less well on tasks measuring executive control, their ability to access the semantic store in a goal driven manner may be compromised. Older adults also consistently show reductions in intrinsic brain connectivity, and we examined how these brain changes relate to age-related changes in semantic performance. We found that while older participants outperformed their younger counterparts on tests of vocabulary size (i.e., NART), younger participants were faster and more accurate in tasks requiring semantic control, and these age differences correlated with measures of intrinsic connectivity between the anterior temporal lobe (ATL) and medial prefrontal cortex (mPFC), within the default mode network. Higher intrinsic connectivity from right ATL t...

Source: Neuropsychologia - July 4, 2019 Category: Neurology Source Type: research