Different Study Designs When Investigating Cognitive And...

1. There are various advantages and disadvantages of different study designs when investigating cognitive and neural ageing using neuroimaging. Several theories of cognitive ageing have been based on cross-sectional designs where there is a common understanding that multifarious age studies can lead to a better understanding of the propinquity among age-related processes (Hofer, Sliwinski and Flaherty, 2002). This method is proven to be cost effective, renders quick results, and is the best way to determine prevalence and identifying associations within a group (Mann, 2003). However, Salthouse (2009) pointed out that comparisons of people of different ages at a particular time does not necessarily express changes that will arise within an individual as he ages. He explained that confounding factors, such as maturation, which refers to the person growing older and undergoing different experiences and influences, must be determined in each participant to know how each one h as been effected. Raz and Kennedy (2009) also identified in a review that cross-sectional studies have often only focused on specific parts of the brain in imaging studies, such as the prefrontal cortex, but many longitudinal studies present larger age-related structural changes in the inferior parietal cortex, the hippocampus, and the cerebellum. Compared to cross-sectional studies, research on ageing have argued that longitudinal is the most practical way to obtain reliable data, stating that,