Gibbs Marie E, Johnston Amy N B, Mileusnic Radmila, Crowe Simon F
Department of Anatomy and Developmental Biology, Monash University, Clayton 3800, Australia.
Brain Res Bull. 2008 Jun 15;76(3):198-207. doi: 10.1016/j.brainresbull.2008.02.032. Epub 2008 Mar 18.
A one-trial learning task, where chicks learn that a bead of a particular shape and/or colour has a bitter taste (because it has been coated in 100% methyl anthranilate, MeA) and subsequently avoids it on test, has been widely used by research groups across the world. However, there are some differences in the results reported by different research laboratories. One important difference is found when chicks are trained with a diluted bitter taste on the bead (10 or 20% MeA); memory is not consolidated and fades, lasting for different times. At Monash and La Trobe Universities, memory lasts for 30 min but at the Open University (OU), memory lasts for 4-6h before fading. Differences in protocol that may explain this apparent discrepancy are whether the chicks have seen the bead before (novelty) and whether the colour or the shape of the bead is an important feature. In this review, we discuss these and other factors that may contribute to the differences in the characteristics of memory processing at Monash and at the OU, such as chick strain, hatchery or laboratory incubated chicks, age at training. It is clear that there is a difference between passive avoidance and discriminative avoidance protocols and this may explain the differences in duration of the memory with weakly reinforced learning. Is the OU task a more salient experience because of the novelty of the bead and therefore a 'stronger' learning experience? The different protocols may allow different questions to be addressed.
一种单次尝试学习任务，即雏鸡学会特定形状和/或颜色的珠子有苦味（因为它被涂上了100%的邻氨基苯甲酸甲酯，MeA），随后在测试中避开它，已被世界各地的研究团队广泛使用。然而，不同研究实验室报告的结果存在一些差异。当用稀释的苦味训练雏鸡（10%或20%的MeA）时，会发现一个重要差异；记忆没有巩固且会消退，持续时间各不相同。在莫纳什大学和拉筹伯大学，记忆持续30分钟，但在开放大学（OU），记忆在消退前持续4 - 6小时。可能解释这种明显差异的实验方案差异在于雏鸡之前是否见过珠子（新颖性）以及珠子的颜色或形状是否是一个重要特征。在这篇综述中，我们讨论这些以及其他可能导致莫纳什大学和开放大学记忆处理特征差异的因素，如雏鸡品系、孵化场或实验室孵化的雏鸡、训练时的年龄。很明显，被动回避和辨别回避实验方案之间存在差异，这可能解释了弱强化学习中记忆持续时间的差异。由于珠子的新颖性，开放大学的任务是否是一种更显著的体验，因此是一种“更强”的学习体验？不同的实验方案可能允许解决不同的问题。
