Rogers P J, Tonkiss J, Smart J L
Dev Psychobiol. 1986 Mar;19(2):113-24. doi: 10.1002/dev.420190204.
Rats were either well-nourished (control) or undernourished (PU) during the suckling and early post-weaning periods (birth to 45 days), after which all animals were fed ad libitum. From 25 to 45 days half of the rats in each group were exposed continuously in their home cases to shape stimuli (triangles and circles). Half of each of these 4 groups were given "reminders" of the stimuli through exposure for 2 h every 10-12 days from 55 to 131 days. Beginning on day 132, ability to discriminate these same visual stimuli was tested using a nonappetitively motivated version of the Lashley jumping stand technique. Discrimination learning per se was unimpaired by previous undernutrition (control and PU rats not viewing the stimuli prior to training performed equally well). However, early-life exposure led to improved learning performance only in control rats; it had no effect on the performance of PU rats (significant exposure X nutrition interaction). These findings indicate that undernutrition interfered with early "incidental learning", that is, learning about features of the environment which are not, at the time, biologically relevant. Finally, retention of the discrimination was assessed 9 weeks after the rats had attained criterion performance. There were no effects of nutrition or prior exposure on long-term memory.
在哺乳期和断奶后的早期阶段（出生至45天），将大鼠分为营养良好组（对照组）和营养不良组（PU组），此后所有动物均可自由进食。在25至45天期间，每组一半的大鼠在其饲养箱中持续暴露于形状刺激物（三角形和圆形）。在这4组中，每组又有一半的大鼠在55至131天期间每10 - 12天接受2小时的刺激“提醒”。从第132天开始，使用无食欲动机的拉什利跳台技术测试大鼠区分这些相同视觉刺激的能力。辨别学习本身并未受到先前营养不良的影响（训练前未观看刺激物的对照组和PU组大鼠表现同样良好）。然而，早期接触仅在对照组大鼠中提高了学习成绩；对PU组大鼠的表现没有影响（存在显著的接触×营养交互作用）。这些发现表明，营养不良会干扰早期的“偶然学习”，即对当时与生物学无关的环境特征的学习。最后，在大鼠达到标准表现9周后评估辨别能力的保持情况。营养状况或先前的接触对长期记忆没有影响。
