Imaging genomics: Brain alterations associated with the APOE genotype
Traditionally, most neuroscience research has focused on universal features. Neuroimaging is no exception. The majority of studies until now have aimed at mapping common brain characteristics that are shared by a large population. However, as evidenced by a growing trend in the research literature, more recent neuroimaging studies have shifted focus to also pay attention to individual variability and dynamic variation. For instance, recent results have revealed substantial inter-individual variance in how the brain processes various cognitive tasks (Grabner et al., 2007; Hariri et al., 2003) or emotions (Hamann & Canli, 2004), as well as individual diﬀerences in brain development (Bengtsson et al., 2005) and aging (Cabeza, Anderson, Locantore, & McIntosh, 2002; Persson et al., 2006b; Raz et al., 2005). This shift in attention – from more general characteristics towards individual variance – can probably be seen as a natural next step after the successful mapping project, but it should also be ascribed to rapid advances in non-invasive brain imaging techniques, as well as to recent insights into the human genome and genetic variation (International Human Genome Sequencing Consortium, 2001; Venter et al., 2001).