This experimental paradigm appears to be very effective in recasting attentional allocation. James J. Gibson is credited with recasting direct perception as ecological perception. The producers originally considered recasting the role of Prue with a different actress. UA considered recasting the role before convincing Blake Edwards to return to the series. Producers introduced the concept of regeneration to permit the recasting of the main character. The recasting of other voice actors caused some controversy. Angular momentum algebra can often be simplified by recasting it in the spherical basis. Many of the changes, in particular the recasting of Mrs Pike, met with criticism. Executives disliked the original cast and held auditions for recasting. CBS leaked rumors of recasting, but the actor eventually prevailed. When recasting the role for 2009's "Star Trek", Nimoy was asked his opinion. Originally Tony Leung was going to appear but scheduling conflicts led to the recasting. NRW had initially thought about recasting Ritter at the last minute before the pilot taped. Greek customs and fashions contributed to the recasting of east Balkan society. In 2006, the Council sought to improve on the Sixth Directive by recasting it.