Delayed Matching and Short-Term Memory in Monkeys

This chapter describes the experimental situation and procedures that are common to all of the studies of delayed matching and short-term memory in monkeys, which are capuchin monkeys who, before their paradigm delayed matching-to-sample (DMTS) experience, are in laboratory residence from one to four years.

Abstract

Delayed matching can be dramatically facilitated by the simple operation of extinguishing all illumination during the delay (retention) interval. This chapter describes the experimental situation and procedures that are common to all of the studies of delayed matching and short-term memory in monkeys. All experimental subjects are capuchin monkeys (Cebus apella) who, before their paradigm delayed matching-to-sample (DMTS) experience, are in laboratory residence from one to four years, during which they were exposed to various kinds of experimental training. Motivation is induced by food deprivation, the animals being reduced to a body weight at which they work with reasonable diligence. After completing 15 responses on the microswitch, one of the stimuli (the sample) appears on the center projector and remains there until the subject pressed the center key for a minimum duration of 0.3 seconds. The sample then disappears and the delay (retention) interval begins.