Mindfulness meditation training and attention in older adults : an ERP study

Given the current and predicted physical and financial costs of cognitive decline in older adults, considerable research attention has focussed on finding interventions effective in slowing or reversing this decline. More recently, mindfulness meditation practices, derived from Buddhist meditation techniques have been considered as possible attentional training tools. The present study examined the electrophysiological correlates of attention in healthy older adults before and after 10 weeks of mindfulness meditation training in the Vipassana tradition. A visual threestimulus oddball paradigm was employed and accuracy and reaction time measures, as well as event related potentials (ERPs) were compared before and after the mindfulness meditation course. Mean amplitude and peak latency of ERP components P3a and P3b were measured in response to the novel and target stimuli in the oddball task respectively at the two time points. Participants were 16 healthy adults aged between 60-85 years (M= 68.13, SD = 7.22) with no previous meditation experience. Results failed to show support for the hypotheses that mindfulness training would be associated with improved performance on behavioural measures and reduced P3a and P3b amplitude and latency as elicited by the novel and target stimuli respectively. The implications of these results were considered in context of the varied results of previous work in the study of the relationship between mindfulness meditation and attention, particularly in older adults. Recommendations for future research centre on the need for rigorously conducted randomised controlled trials to further explore this relationship and the potential for mindfulness meditation to be incorporated into cognitive training programs. Separate from the declines in cognitive domains seen in different forms of dementia, cognitive decline is also a normal consequence of ageing in otherwise healthy individuals (Epel, Daubenmier, Moskowitz, Folkman, & Blackburn, 2009; Slagter, Davidson, & Lutz, 2011). Older adults show not only general slowing of information processing, but also deteriorations in specific higher cognitive functioning. This age-related cognitive decline has been found to occur across a variety of cognitive domains, such as: episodic memory; visuo-spatial skills; and executive functioning including working memory and attention (Buckner, 2004; Hseih, Liang, & Tsai, 2011). Such declines may have a significant effect on an individual's ability to live independently and undertake various activities of daily living; and subsequently, their quality of life may decline (Wolinsky et al., 2006). Given the current and projected increases in the number of elderly Australians (particularly over 65 years), concerns have not only been raised about the effect of such a decline in quality of life, but also regarding the financial impact that such age-related cognitive decline will continue to have (Australian Government, 2010). It is estimated that there were 266, 574 people living with dementia in Australia in 2011 and it is suggested that there are many more with cognitive impairment. This figure is projected to increase to 553, 285 people by 2030 and 942,624 people by 2050 (Access Economics, 2011). Tasmania, in particular, has shown the largest increase in median age over the past 20 years (1990-2010); including a 200% increase in the 85 years plus age group (Australian Government, 2010). Across all age groups, the number of people living with dementia in Tasmania in 2011 was 6,732 and this is projected to increase to 20,653 by the year 2050 (Access Economics, 2011). Cost estimates of the impact of cognitive decline in this ageing population vary; however, it is predicted that by 2060 spending on dementia will outstrip that of any other health condition. Total spending is projected to be $83 billion and will represent around 11% of the entire health and residential aged care sector spending (Access Economic, 2011). Previous research estimates that delaying the onset of Alzheimer's disease in individuals by five years could save up to $67.5 billion dollars by the year 2040 (Access Economics, 2007). These concerns, combined with an increasing understanding of the neurophysiological consequences of ageing, have led to an increase in research focussing on interventions aimed at slowing cognitive decline in older adults (Slagter et al., 2011; Wolinsky et al., 2006). Much of this research has focussed on implementing and assessing the effectiveness of behavioural interventions aimed at increasing mental activity and therefore, it is argued, slowing the rate of cognitive decline in the ageing brain (see Beason-Held, Kraut, &Resnik, 2008). Research has provided mixed evidence as to the effectiveness of such behavioural interventions. Whilst some large-scale longitudinal studies have indicated that such behavioural interventions may result in task specific learning and, consequently, slowing in specific areas of cognition, few have resulted in more than a slight improvement in any cognitive domain (Bablioni et al., 2006; Jennings, Dagenbach, Engle, F Slagter et al., 2011). Further, there are conflicting results regarding the effect of these interventions on more general cognitive functions, or of transfer of improvements into other areas of daily functioning. That is, training benefits are often stimulus or content specific rather than process specific (Slagter et al., 2011). Accordingly, a number of researchers have suggested that providing training that is more process specific may help to overcome some of these limitations (Epel et - at, 2009; Geng, Zhang, & Zhang; 2011; McHugh, Simpson, & Reed; 2010;-Slagter et al., 2011). These processes, for example attention, are argued to be fundamental to a wide range of cognitive aspects and therefore contribute to performance over a wide range of cognitive tasks (Slagter et al., 2011).