Assessing the use of thematic and taxonomic relations in healthy ageing.

The primary aim of the grant is to follow up on previous findings on the use of thematic and taxonomic categorisation in healthy aging. It is known that older adults process the world differently to younger adults (Mather & Cartenson, 2005; Reed, Chan & Mikels, 2014). Explanations for such processing differences range from OAs using different strategies (Wurm, 2011) to age related decline in brain regions (Caccioppo et al., 2011). Shipp and Anthony (in prep) previously used the odd-one-out task to demonstrate age-related differences in taxonomic and thematic processing. Participants were instructed to find the oddball amongst concrete and abstract words which were thematically (e.g., library-bookcase-shelf-RHINO, weight-gravity-space-LUXURY) or taxonomically linked (finch-robin-sparrow-SNAKE, goal-aim-purpose-LOAN). They found that OAs show an advantage for thematic processing whereas YAs show an advantage for taxonomic processing, irrespective of the word type. This adds a new dimension to the literature which seeks to understand why OAs exhibit differences in processing information.

One important relationship that connects objects to each other in our thinking is their shared membership in a category. For example, finch, robin and sparrow are related because they are all birds. However, objects are also seen as related if you come across them together in the same situations, so bucket, spade and sand are related because they can all be found at the beach. Adults are very good, and very fast, in stating whether or not objects are related based on a shared category or situation. Furthermore, adults are faster at identifying objects that can be physically touched (e.g., table, chair) compared to those that cannot (e.g., space, time). This has been linked to age differences; older adults are faster at identifying objects which share a situation while younger adults are faster at identifying those which belong to the same category. The manner in which older adults process information may be interlinked with wider age-related changes and/or strategies that compensate for worsening cognitive abilities. The aim of the current research is to further investigate and understand these age differences, with a specific focus on the processing of words that refer to things that can be physically touched or not.