The Downside of Spatial Normalisation in fMRI of Medial Temporal Lobe Structures
Liptrot M, Nielsen F, Baare W, Jernigan T, Christensen M, Ramsy T, Lund T, Sidaros K
Copenhagen University Hospital, Hvidovre
The objective was to investigate the degree that functional and anatomical variance of medial temporal lobe structures, specifically the perirhinal cortex, impacted upon group analyses after standard spatial normalisation. The perirhinal cortex has been indicated as the initial location of damage in Alzheimer's disease, and so a paradigm enabling its reliable activation may allow presymptomatic detection of cortical degradation. Such clinical use would require a standardized template, yet standard spatial normalisation techniques are shown here to greatly affect the location of both the activations and anatomical regions. This has significant implication for any group analyses of the medial temporal region.