Good Morning America/Youtube; David Becker/Getty Emma Heming Willis opened up to Diane Sawyer about seeing flashes of husband Bruce's "warm" personality amid his frontotemporal dementia (FTD) diagnosis "As quickly as those moments appear, then it goes," she said, through tears, in a preview of the interview that aired onGood Morning AmericaTuesday, Aug. 26 Emma & Bruce Willis: The Unexpected Journeyairs in full on ABC Tuesday at 8 p.m. ET, and streams the next day on Hulu and Disney+ Emma Heming Willisis opening up about the moments she sees flashes of her husband's "warm" personality amidhis frontotemporal dementia (FTD) diagnosis. During a preview of her sit-down withDiane Sawyerthat aired onGood Morning AmericaTuesday, Aug. 26, Emma said her family still has "moments" where the actor, 70, displays flashes of his charismatic personality. "It's his laugh, right? He has such a hearty laugh," said Emma, 47. "And sometimes you'll see that twinkle in his eye, or that smirk. I just get transported." Through tears, she added, "And it's just hard to see, because as quickly as those moments appear, then it goes," snapping her fingers. Never miss a story — sign up forPEOPLE's free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human-interest stories. In March 2022, the Willis family revealedBruce had been diagnosed with aphasia, a language disorder that affects the ability to communicate, and was retiring from acting. In February 2023, Emma then revealed Bruce's frontotemporal dementia diagnosis. Speaking with Sawyer, 79, the model, author and activist recalled of realizing something was different in her husband ahead of his diagnosis, "For someone who was very talkative and very engaged, he was just a little more quiet." "And when the family would get together, he would kind of just melt a little bit," she explained. As Emma further recalled of theDie Hardstar, "He felt a little removed, very cold. Not like Bruce, who is very warm and affectionate. To go in the complete opposite of that was alarming and scary." Larry Busacca/Getty Emma, whose bookThe Unexpected Journeywill be available Sept. 9, said she doesn't believe her husband "ever connected the dots" about what was happening to him health-wise. As for her own reaction, she told Sawyer she felt "panicked" not fully understanding what was happening to Bruce, after he was given "a diagnosis I couldn't pronounce." "I just remember hearing it and just not hearing anything else. It was like I was free-falling," she said. Emma — who shares daughtersMabel, 13, andEvelyn, 11, with Bruce — also shared that "FTD can be diagnosed as bipolar, midlife crisis, depression," adding that "a lot of doctors don't know about" the condition at all. But despite the challenges, "I'm grateful," she told Sawyer. "I'm grateful that my husband is still very much here." Emma & Bruce Willis: The Unexpected Journeyairs in full on ABC Tuesday at 8 p.m. ET, and streams the next day on Hulu and Disney+. Read the original article onPeople