Sequelize can update data with !value, but fails to update with boolean value

Question

I recently started learning MySQL and get a little problem.

First:

words.findByPk(req.params.id)
  .then(word => {
    return word.update({
      test: !word.dataValues.test
    })
  })

Second:

words.findByPk(req.params.id)
  .then(word => {
    word.dataValues.test
     ? word.dataValues.test = false
     : word.dataValues.test = true
    return word.update({
      test: word.dataValues.test
    })
  })

I don't know why the first way works to update the repository and the second fails. Using "console.log" results are true or false.