Same/different concept learning by primates and birds

Same/different abstract-concept learning experiments were conducted with two primate species and three avian by progressively increasing the size of training stimulus set distinctly different pictures from eight to 1,024 pictures. These same/different trained presented simultaneously. Transfer tests same employed interspersed trials novel assess level correct performance on very first time subjects had seen those All eventually performed these high accuracy, contradicting long-accepted notion that nonhuman animals are unable learn concept same/different. Capuchin rhesus monkeys learned more readily than did pigeons. Clark’s nutcrackers black-billed magpies as monkeys, even showed a slight advantage smallest sets. Those followed delay procedures, such was introduced after responded sample picture before test picture. In sequential task, accuracy shown diminish when previous trial matched previously trial. This effect is known proactive interference. The pigeons’ interference greater at 10-s delays 1-s delays, revealing time-based By contrast, little or no monkeys’ interference, suggesting have better explicit memory where they saw potential interfering picture, event-based memory.