Article : The Effect of Positive and Negative Item Phrasing on the Measurement of Attitudes.

You will find the find notes on this issue by searching www.rasch.org

The key principle is: reverse scoring a negative does NOT necessarily align it with the positive latent trait. They should be considered 2 scales until you can demonstrate they are ONE. My advice: don't use neg worded items. Experts say this is for detecting response bias or liars. But an attitude scale is based on trusting the respondents and having good communication with them via your instrument. Negative items usually destroy both trust and communication.

Credit : Trevor Bond