HRF {BayesfMRI}

Canonical (double-gamma) HRF

Description

Calculate the HRF from a time vector and parameters. Optionally compute the first or second derivative of the HRF instead.

Usage

HRF(t, deriv = 0, a1 = 6, b1 = 0.9, a2 = 12, b2 = 0.9, c = 0.35)

Arguments

t

time vector

deriv

0 (default) for the HRF, 1 for the first derivative of the HRF, or 2 for the second derivative of the HRF.

a1

delay of response. Default: 6

b1

response dispersion. Default: 0.9

a2

delay of undershoot. Default: 12

b2

dispersion of undershoot. Default: 0.9

c

scale of undershoot. Default: 0.35

Value

HRF vector (or dHRF, or d2HRF) corresponding to time

Examples

downsample <- 100
HRF(seq(0, 30, by=1/downsample))