Paradigms of motivation often examine the performance of subjects in tasks associated with rewards. In this study, the aim was to develop a new behavioural test associating a natural reward (familiar food) to an effort task in rats (climbing a ladder). Wistar rats (both sexes, 90–120 days) were familiarised with food (chow, chocolate, corn flakes, fruit loops) in their home cage for four days before being tested for food preference. Food preference varied from rat to rat. Afterwards, rats were randomly allocated into the two groups, spontaneous (females, n = 10; males, n = 11) or reinforced (females, n = 9; males, n = 10) right before the training in the ladder. The climbing-task test consisted of one session of fifteen minutes (pre-trial) followed by two training sessions and a test trial of five minutes each, at 1, 7 and 14 days after pre-trial, respectively. In the pre-trial, more females climbed spontaneously the ladder than males (females: 11 out of 19, males: 3 out of 21). Food or training were minor reinforcements to climbing the ladder for male rats. In contrast, training decreased latency to climbing in females of both experimental groups and increased climbing frequency of reinforced females in the test trial. Summarising, female rats were more intrinsically motivated to climb the ladder than males. In contrast with males, incentives increased motivation in female rats to perform the effort task. Hence, at the current moment, climbing-task test seems more promising to estimate motivation in female rats.

动机范式通常检查受试者在与奖励相关的任务中的表现。在这项研究中，目的是开发一种新的行为测试，将自然奖励（熟悉的食物）与大鼠的努力任务（爬梯子）联系起来。在测试食物偏好之前，Wistar 大鼠（两性，90-120 天）在他们的笼子里熟悉食物（食物、巧克力、玉米片、水果圈）四天。食物偏好因大鼠而异。然后，在梯子训练之前，将大鼠随机分为两组，自发组（雌性，n = 10；雄性，n = 11）或强化组（雌性，n = 9；雄性，n = 10）。攀爬任务测试包括一次 15 分钟的训练（预试），然后是两次训练和一次 5 分钟的测试试验，分别在预试后的 1、7 和 14 天，分别。在预审中，自发爬上梯子的女性多于男性（女性：19 人中有 11 人，男性：21 人中有 3 人）。食物或训练是雄性老鼠爬梯子的次要增援。相比之下，训练减少了两个实验组女性攀爬的潜伏期，并增加了测试试验中强化女性的攀爬频率。总而言之，雌性大鼠比雄性更具有爬梯子的内在动机。与雄性相比，激励增加了雌性大鼠执行努力任务的动力。因此，目前，攀爬任务测试似乎更有希望估计雌性大鼠的动机。食物或训练是雄性老鼠爬梯子的次要增援。相比之下，训练减少了两个实验组女性攀爬的潜伏期，并增加了测试试验中强化女性的攀爬频率。总而言之，雌性大鼠比雄性更具有爬梯子的内在动机。与雄性相比，激励增加了雌性大鼠执行努力任务的动力。因此，目前，攀爬任务测试似乎更有希望估计雌性大鼠的动机。食物或训练是雄性老鼠爬梯子的次要增援。相比之下，训练减少了两个实验组女性攀爬的潜伏期，并增加了测试试验中强化女性的攀爬频率。总而言之，雌性大鼠比雄性更具有爬梯子的内在动机。与雄性相比，激励增加了雌性大鼠执行努力任务的动力。因此，目前，攀爬任务测试似乎更有希望估计雌性大鼠的动机。激励增加了雌性大鼠执行努力任务的动力。因此，目前，攀爬任务测试似乎更有希望估计雌性大鼠的动机。激励增加了雌性大鼠执行努力任务的动力。因此，目前，攀爬任务测试似乎更有希望估计雌性大鼠的动机。