Star Trek: 10 Things You Didn't Know About Kathryn Janeway

At its most extreme, method acting is a performance technique whereby the actor, essentially, becomes the character, to deliver an authentic performance. 

Theatre practitioner, Stella Adler, proposed that rather than go to such extreme measures, an actor should research all there is to learn about a character's given circumstances and then use that research to inform their acting choices for the role. Kate Mulgrew studied under Stella Adler at the beginning of her acting career and it has been well documented that she did, indeed, do extensive research into the scientific and technological elements of her role as Captain Janeway. 

When it came to filming season 4’s Scientific Method, however, it would seem that Mulgrew, temporarily, brushed her mentor’s teachings aside and opted for the more extreme practice of method acting. 

The premise of this episode saw the Voyager crew suffering the effects of an unseen species performing various experiments on them. For Chakotay, this resulted in rapid ageing. For Neelix it caused his body to start mutating into a different species. And for Janeway, the result was intense migraines - not surprising when the countless needles sticking into her head are later revealed. 

At the time, Mulgrew was in the process of quitting smoking and used her personal experience to aid her performance. Using her existing symptoms of withdrawal - heightened irritability, stress, exhaustion - she was able to embody the physical state of the haggard Captain Janeway and deliver a truly “method” performance.