HI! Noticed this was listed a few yrs ago, did you ever get any answers? We have been goin through something very similiar and bein doin alot of testing. It'd be cool to compare notes.
Hello,
Your son can be having short term memory loss although it is very very rare at this age.It is not normal for a 6 year old child.It can represent some problem with the amygdla or parahippocampus in the brain. Amygdala controls present thoughts and short term memory. The parahippocampal controls past thoughts or long term memory.
Other possibility is of ADHD(attention deficit hyperactive disorder). It typically presents itself during childhood, and is characterized by a persistent pattern of inattention and/or hyperactivity, as well as forgetfulness, poor impulse control or impulsivity, and distractibility.
Pls discuss these two possibilities with your doctor preferably a child psychiatrist or pediatric neurologist.
Hope it helps.Take care and pls do keep me posted on how your son is doing.