Differential neural responses to overt and covert presentations of facial expressions of fear and disgust. - Mary L. Phillips; Leanne M. Williams; Maike Heining; Catherine M. Herba; Tamara A. Russell; Christopher Andrew; Edward T. Bullmore; Michael J. Brammer; Steven C. R. Williams; Michael Morgan; Andrew W. Young; Jeffrey A. Gray (NeuroImage, 2004)