Qpsy

library(quickpsy)
dta <- read.table("data.txt",h=T)
dta$N <- 30
respS <- dta[c(1:9,19:27),]
respL <- dta[c(10:18,28:36),]    
fit <- quickpsy(respL, oddball,trial,N,grouping=.(color))

Estimating parameters...
Performing bootstrap...

plotcurves(fit)+
        scale_colour_manual(values=c("blue","red"),
                            name = "Condition",
                            labels = c("Blue Light","Red Light"))+
        theme_bw()+
        labs(list(title = "Psychometric Function of Subject XX",
                  x = "Oddball Time",
                  y = "Probabilty of choosing 'Long' "))+
        scale_x_continuous(breaks=c(745,828,895,978,1045,1128,1195,1278,1345))