uintercept =~ 1*use1 + 1*use2 + 1*use3 + 1*use4
uslope =~ 0*use1 + 1*use2 + 2*use3 + 3*use4
uintercept ~ ease
uslope ~ ease
#
pintercept =~ 1*prof1 + 1*prof2 + 1*prof3 + 1*prof4
pslope =~ 0*prof1 + 1*prof2 + 2*prof3 + 3*prof4
pintercept ~ ease
pslope ~ ease
