Harrison Ford claims that Michael J. Fox's "humour and courage" are evident as he returns to acting in 'Shrinking'

Harrison, 82, told People: "His willingness to be part of our show is a great source of inspiration and gives us a real purpose.

"It's not just us coming together, two actors. There's a story to tell, and our commitment to the story is what joins us together. I appreciate his willingness to be part of the show."

In 'Shrinking', the 'Indiana Jones' legend plays the role of Dr. Paul Rhoades - a therapist who must navigate his own Parkinson's diagnosis - and revealed that Michael, 63, has informed his portrayal of the condition in a "subtle" way.

Harrison explained: "I'm sure that there are subtle things that will show up later.

"When we were together, it was an accomplishment of all of us trying to meet all the ambitions, both obvious and attendant, to the ideas we're trying to deal with.

"I've done what I could to acquaint myself with the aspects of the disease that I'm portraying, and I'm at a much different stage of the disease."

The 'Star Wars' actor added: "My character's in a much different stage of the disease than Michael's.

"But Michael, as Bill (Lawrence, series co-creator) points out, is totally there on the intellectual level. And emotionally, his humour and his courage are evident."

Harrison recently said that he takes his role in 'Shrinking' "deadly f****** seriously" and feels a huge responsibility to show the reality of life with Parkinson's on screen.

He said: "There's no intention to make it into a joke, but there are people that absorb these kinds of experiences with grace and courage and a little bit of wisdom. And that is not to say that some people do not.

"It's just to say that this is a person particularly equipped to communicate what it is that it's like, and that is something that I feel that is worth sharing with our audience."