A novel food-delivery device for neurophysiological and neuropsychologicalstudies in monkeys

Neurophysiological and neuropsychological studies in monkeys sometimes requ ire an automated food-pellet dispenser. Commercially available dispensers t ypically sequester the pellet until delivery and, once delivered, the pelle t's availability cannot be controlled. The custom-designed dispenser descri bed here overcomes those two limitations. The device is composed of two sep arate units: a feeder and an electronic controller. The feeder manipulates food pellets with actuators driven by air pressure and delivers them into a serving bowl. The controller's settings determine whether the monkey can r etrieve a pellet from the bowl. If the experiment requires that the pellet be visible and within reach, but unavailable for retrieval, the controller enables a trap-door mechanism at the bottom of the bowl. Any motion near th e serving bowl, such as that caused by the approach of a monkey's hand, wil l then trigger the opening of the trap door, which causes the pellet to fal l into an enclosed pellet collector. This rapid pellet-removal mechanism ca n also be triggered by other computer-controlled contingencies. Two of thes e dispensers have been in operation in an applied laboratory setting for ov er 2 years. Published by Elsevier Science B.V.