Parse this person name:

Karen Johnson, 1950-1991, flourished 1974-1986
user
first_name: Karen
last_name: Johnson
middle_names: []
temporal:
- start: 1950
  end: 1991
  type: life_span
- start: 1974
  end: 1986
  type: flourished
titles: []
extra_info: []
assistant