¥Regression Analysis: 3dRegAna
HSimple
linear regression:
åY =
b0 + b1X1,+
e
åwhere
Y represents the FMRI measurement (i.e., percent signal change) and X is the independent variable (i.e., drug
dose)
HMultiple
linear regression:
åY =
b0 + b1X1 +
b2X2 +
b3X3 +
É+ e
HRegression
with qualitative and quantitative variables (ANCOVA)
åi.e.,
drug dose (5mg, 12mg, 23mg, etc.) is quantitative while drug type (Nicotine, THC, Cocaine) or age group (young vs. old)
or genotype is qualitative, and usually called dummy (or indicator)
variable
HANOVA
with unequal sample sizes (with indicator variables)
HPolynomial
regression:
åY =
b0 + b1X1 +
b2X12 +
É + e
HLinear
regression: model is a linear function of its unknowns bi ,
NOT its independent variables Xi
HNot
for fitting time series, use 3dDeconvolve
(or 3dNLfim) instead