Strategic Promotion of Ageing Research Capacity Where’s that Word? Word finding problems in older age

Difficulties with word retrieval, especially when naming a well-known face or object, is part of the normal ageing process, but older people fear that it could be a sign of encroaching dementia. Surprisingly, little is known about these tip-of-the-tongue situations (TOTs). In this study, groups of older and younger participants were shown a series of famous faces. At the same time, their brains were scanned using Magnetic Resonance Imaging (MRI). The findings from this research help contradict the assumption that TOTs in old age reflect a general memory deficit. Instead, the difficulty appears to be localised, low-level, and specifically to do with word production and the retrieval of the form of words, rather than the higher-level meaning of those words. • The study found that here were age-related differences in the ability to retrieve words, and a higher incidence in TOTs for older people. When successfully retrieving words though, older adults activated similar regions of the brain to younger adults, and there was no age-related difference in activity in the part of the brain known to be important for word retrieval (the insula). • When trying to retrieve a difficult word there was a boost of activity in the insula. This boost was linked to overall better performance (lower TOT rates), suggesting that the boost of activity helped to overcome retrieval difficulty. However when a TOT was encountered, the boost was over and above that found during successful word retrieval. • The boost of activity in the insula of older adults was found to be smaller than that of younger adults. Thus, older adults' smaller activity boost during TOTs may explain why they typically have more TOTs compared to younger adults. • When participants were divided into groups according to the amount of grey matter (important for processing sensory information) in the region of their brain known as the insula, no difference in activity was found when word retrieval was successful. • However when experiencing difficult retrieval leading to a TOT, participants with lower grey matter content in their insula had smaller boosts of activity compared to the high grey matter group. Introduction The Issues Although many cognitive abilities are preserved across the adult lifespan, a major concern for many older people is that those cognitive functions which decline with age (for example, memory, attention, perception, problem solving, mental imagery) are a precursor to conditions such as dementia. One of …