Fig. 4. Interleaved timing of 60 automatically administered trials during one experimental night with three animals sequentially exchanged between the 64-feeder array (trial) and their individual cages (inter-trial). Shading indicates trial at the feeder array (black), enclosure phase (horizontal stripes), animal in cage before and after a series of experimental trials (dark grey). Feeders at array are active (black circles) or inactive (open circles) but indistinguishable in external appearance (not cued) for the test animal.