ten minutes before the fluorodeoxyglucose (FDG) injection (used to produce coloured images of the different levels of brain activity,) each participant were given practice trials on a continuous performance task (CPT.)
2)the task was started 30 seconds before the FDG injection, so that initial task novelty would not affect the results of the PET scan
3) the FDG tracer was injected into each participant.
4) the FDG was taken up by the brain for a 32-minute period during which the participant completed a CPT.
5) the participant was then transferred to a PET scanner where the brainwasscanned in 10mm horizontal slices using the cortical peelandboxtechnique.