Ð16Ð
Linearity
of HRF
¥ Multiple
activation cycles in a voxel, closer in time than duration of HRF:
H Assume that
overlapping responses add
¥ Linearity is a pretty good
assumption
¥ But not apparently perfect Ñ about 90% correct
¥ Nevertheless, is widely taken to be true and is the basis for the Ògeneral linear modelÓ (GLM) in FMRI analysis
¥ But not apparently perfect Ñ about 90% correct
¥ Nevertheless, is widely taken to be true and is the basis for the Ògeneral linear modelÓ (GLM) in FMRI analysis
3
Brief Activations