# Linear mixed effect model in priming experiment

#### rainamo

##### New Member
we conducted a priming experiment. subjects and items are randomly chosen, so we need to have by-item and by-subject analysis. In the experiment, we’d examine how our factors of interest (status, gender, lexicalstatus) affect participants’ response (accuracy, reaction time). We would examine the main effect and all interactive effects, and this should be done with linear mixed effect model (do I need to use repeated measurement? what is the repeated measurement, and what are the differences between repeated measure ANOVA and by-subject ANOVA?), however since I'm new in R, I would like to ask how to realize that. Please give me some detailed coding for example, so that I can know how to operate the remaining parts by myself. The following is what I did in R, and if there is anything wrong, please help me correct them Appreciate your help in advance! For example, to see whether participants' status will affect their response time significantly, we try to use the following command, but wonder what is the difference between the following commands:

experiment1.model=lmer(resp~status+(1|sub)+(1|itemNr),data=experiment1) experiment1.model=lmer(resp~status+(1|sub),data=experiment1) experiment1.model=lmer(resp~status+(1|itemNr),data=experiment1)

summary(m) [IS THIS REPEATED MEASURE ANOVA?]

Or should we use following command instead:

experiment1.model1=lmer(resp~ 1 +(1|sub)+(1|itemNr),data=experiment1) experiment1.mode2=lmer(resp~status +(1|sub)+(1|itemNr),data=experiment1)

anova (experiment1.model1,experiment1.model2)

And to calculate the interaction, for example, the two-way interaction between status and gender, should we use:

experiment1.model1=lmer(resp~status*gender+(1|sub)+(1|itemNr),data=experiment1)

Or we should use the following instead:

m1 <- lmer(resp~status*gender+(1|sub)+(1|itemNr),data=experiment1, REML=FALSE)

m2 <- lmer(resp~status+gender+(1|sub)+(1|itemNr),data=experiment1, REML=FALSE)

anova (experiment1.model5,experiment1.model6)

One more question is when I run this commands, I find it contains t value, however, I think in my case, probably f value is appropriate, how to realize this?

Thank you again!