[1] Univ Calif Los Angeles, Dept Psychol, Los Angeles, CA 90095 USA
[2] Univ Calif Los Angeles, Brain Res Inst, Los Angeles, CA 90095 USA
[3] Rutgers State Univ, Dept Psychol, Newark, NJ 07102 USA
[4] NEI, Lab Semicond Res, NIH, Bethesda, MD 20892 USA