Study of characteristics of deteriorated abilities in aged monkeys

为了研究猴子的计划能力和年龄对这种能力的影响，我们对老年和年轻的日本猕猴（Macaca fuscata）在食物检索任务中的表现进行了评估。所有的猴子或多或少都表现出系统的反应模式。对反应的系统化分析表明，年轻猴子的系统化强度高于老年猴子。此外，任务表现与反应的系统化程度密切相关。我们在没有任何事先计划的情况下模拟了猴子在这个任务中的表现。结果表明，实证数据远比模拟数据更为系统。我们得出的结论是，猴子可以计划，而且随着年龄的增长，猴子的计划能力会下降，从而导致认知能力下降。

To examine the ability of monkeys to plan and the effect of aging on this ability, performance in a food retrieval task was assessed in aged and younger Japanese monkeys (Macaca fuscata). All of the monkeys showed, to a greater or lesser extent, systematic patterns of response. An analysis of systematization of responses indicated that the strength of systematization was higher in the younger monkeys than in the aged ones. Furthermore, the task performance strongly correlated with the strength of systematization of responses. We simulated the performance in this task by monkeys without any prior plans. Results suggest that the empirical data were far more systematic than the simulated data. Here we conclude that monkeys can plan and that the ability of monkeys to plan deteriorates with age, which causes cognitive decline.