What spatial resolution do we want?
What determines Spatial Resolution?
Why can’t we just collect data from more/smaller voxels?
How large are functional voxels?
How large are anatomical voxels?
Costs of Increased Spatial Resolution
Matching fMRI and electrophysiology
High Spatial Resolution fMRI: Ocular Dominance Columns
Early examples of ocular dominance
Reliability of Ocular Dominance Measurements
Effects of Stimulus Duration on Spatial Extent of Activity
What temporal resolution do we want?
Sampling Rate in Event-related fMRI
Costs of Increased Temporal Resolution
Why do we want to measure differences in timing within a brain region?
Timing Differences across Regions
Timing of mental events measured by fMRI
Width of fMRI response increases with duration of mental activity
Linearity of the Hemodynamic Response
Scaling (A) and Superposition (B)
Possible Sources of Nonlinearity
Differences in Nonlinearity across Brain Regions
Caveat: Stimulus Duration ≠ Neuronal Activity Duration
Hemodynamic Responses to Closely Spaced Stimuli
Refractory Effects in the fMRI Hemodynamic Response
Refractory Effects across Visual Regions
Using refractory effects to study cognition: fMRI Adaptation Studies