Laboratory of Brain Structure, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa, Setagaya, Tokyo 156-8506, Japan.
Neurosci Res. 2011 Nov;71(3):260-5. doi: 10.1016/j.neures.2011.07.1822. Epub 2011 Jul 23.
To analyze decision making under uncertainty of monkeys, common marmosets were trained to choose and remove one of two colored caps on wells arranged side by side. Each well contained constant reward (3 grains of puffed rice) or risky reward (0 or 6 grains; probability, 50%:50%). For each marmoset, white or black color was assigned randomly as a symbol of non-risky or risky choice. Arrangement of white and black caps was determined randomly in each trial. After 200 trials (5 trials per day), the marmosets were classified according to the pattern of their choice. Eight of 18 marmosets (44.4%) were risk-aversive, whereas 5 marmosets (27.8%) were risk-prone. The remaining 5 marmosets (27.8%) preferred to choose one side (left n=4, right n=1). These results showed individual differences in decision making of marmosets. An additional task with reduction in the expected value of the preferred choice revealed that risk-aversive marmosets were slower to adjust their choices to such reductions than risk-prone animals.
为了分析猴子在不确定情况下的决策，我们对普通狨猴进行了训练，让它们选择并移开并排排列的两个井中的一个彩色盖子。每个井中都有固定奖励（3 颗膨化米）或风险奖励（0 或 6 颗；概率为 50%：50%）。对于每只狨猴，白色或黑色随机分配作为无风险或风险选择的符号。在每次试验中，盖子的白色和黑色排列都是随机确定的。在 200 次试验（每天 5 次）后，根据它们的选择模式对狨猴进行分类。18 只狨猴中有 8 只（44.4%）是风险厌恶型，而 5 只狨猴（27.8%）是风险偏好型。其余 5 只狨猴（27.8%）则更喜欢选择一侧（左 4 只，右 1 只）。这些结果表明，狨猴在决策方面存在个体差异。在一项预期价值降低的附加任务中，风险厌恶型狨猴比风险偏好型动物更慢地调整他们的选择以适应这种降低。
