Imprinting behavior in chicks against two-dimensional images presented on the TFT-LCD. (a) Experimental apparatus used to quantify the imprinting behavior. The computer-generated image, which bounced left and right horizontally, was presented on the TFT-LCD. The chick was placed on a running wheel, and the number of forwards and backwards rotations produced by the chick was monitored. (b) Experimental design for training and evaluation. (c) Representative profiles of imprinting when chicks were trained with a red circle (left), blue square (middle) or without training (right). The numbers of revolutions per minute are plotted. A positive value shows movement towards the TFT-LCD. M, matched image; N, new image; SM, shape-matched image; CM, color-matched image. (d) Preference scores against various images for trained chicks (trained with a red circle or a blue square) and for in chicks without training. The preference score was calculated as: (number of revolutions towards the TFT-LCD)/(total number of revolutions during the 5-min test period). Black column, matched image; white column, new image; light-gray column, shape-matched image; gray column, color-matched image. n, number of chicks used. *, P < 0.05; #, P < 0.05.