His mother Shirley heard him giggle, felt him cry properly and watched him try to feed himself.
It may not sound like a big deal, but Caleb, who developed severe cerebral palsy following a massive brain bleed just days after birth, used to suffer up to 30 seizures on an average day, 50 on a bad one.
He often choked when he ate and showed no emotion, making it difficult to tell if he was upset or sick.
But a decision to take him to the United States and Mexico to undergo experimental stem cell treatment in December 2008 has given the Turners a different son.
Doctors are unable to predict the outcome of each treatment and the Turners were warned it might have no effect.
However, after about three months they began to notice small changes in Caleb.
"He's just got the most gorgeous smile. His whole face lights up.
"It makes your day."
They had planned to take Caleb back to Mexico for a second round of stem cell treatment towards the end of last year, but he ended up needing three major operations, to fix shunts in his brain.
The shunts were put in to remove fluid from his brain.
As there was no neurosurgeon in Dunedin at the time, he had to go to Christchurch for the operations. Each operation was four to four and a-half hours long and they were performed within days of each other.
"He really needs to recover properly from that and have a break."
Caleb will travel overseas in February for a second stem cell treatment, which involves the transplant of stem cells from donated umbilical cord blood.
Umbilical cord stem cells are considered adult stem cells and are unrelated to embryonic stem cells.
"We go there with no promises, but all the hope in the world really."
The family has managed to raise most of the cost of the next trip, and a successful art auction held last June raised about $27,000. Each trip costs the family between $35,000 and $40,000.
Fundraising was hard work and stressful, and Mrs Turner was not sure if they would go back for more treatments following the next one.
"It is sort of like gambling. Once you start you think `maybe just one more', but where do you stop?"
