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¥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