ARTIFACTS DUE TO STIMULUS CORRELATED MOTION IN FUNCTIONAL IMAGING OF THE BRAIN

To assess the effect of stimulus correlated motion on the appearance o f functional magnetic resonance images, conventional visual and motor protocols were each performed by four normal volunteers and an image c o-registration technique was used to retrospectively monitor subject m otion. In three studies synthetic data sets were constructed from sing le baseline images using the positional information obtained from the co-registration procedure. Cumulative difference images were then crea ted from both the synthetic and functional image sets. Stimulus correl ated motion was detected in all eight studies and the synthetic cumula tive difference images showed striking similarities to the equivalent functional images in each case.