How can I extract elements of a list?

Question

I am trying to select the upper 95% CI of this data to report in another output. I want to do something like ci$a[upper] but that's not working. Is there a way to do this? Thanks!

a <- rnorm(10)
b <- rnorm(10)
df <- data.frame(a, b)
ci <- map(df, function (x) CI(x, ci=.95))

The output of ci is:

$a
      upper        mean       lower 
 1.27519623  0.62227924 -0.03063774 

$b
     upper       mean      lower 
 0.4755253 -0.1364711 -0.7484675 

I want to do

paste("The mean of a is ",ci$a[upper],sep="")