PowerPoint Presentation - Using AFNI Interactively

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More Sample FMRI Data Time Series

• Second: Event-related FMRI

H “Activation” occurs in single relatively brief intervals

H “Events” can be randomly or regularly spaced in time

≤ If events are randomly spaced in time, signal model itself looks noise-like

H BOLD response to stimulus tends to be weaker since fewer nearby-in-time “activations” have overlapping hemodynamic responses

•Next slide: Visual stimulation experiment

“Active” voxel shown in next slide