Heyselaar Evelien, Johnston Kevin, Paré Martin
Centre for Neuroscience Studies Queen's University, Kingston, Ontario, Canada.
J Vis. 2011 Mar 14;11(3):11. doi: 10.1167/11.3.11.
A core aspect of working memory is that only a limited amount of information can be held at one time, but the investigations of its underlying neural mechanisms in animal models have been dominated by paradigms requiring the retention of a single memorandum. In humans, the information processing limitations of visual working memory have been studied extensively using a sequential comparison procedure, in which subjects detect a change in a multiple-item array following a retention interval. Here, we adopted this approach to study the working memory ability of the macaque monkey. We trained two female rhesus monkeys (Macaca mulatta) to perform a change detection task, in which they were required to report with a saccadic eye movement which one of several items (two to five colored stimuli) in a array had changed color after a 1-s retention interval. Performance gradually declined as a function of set size but always exceeded chance probability. These results show that monkeys possess sufficient information processing capability to perform a visual working memory task requiring the simultaneous maintenance of mnemonic representations of multiple items and validate this animal model for investigation of the neural mechanisms underlying the temporary retention of more than one memorandum.
工作记忆的一个核心方面是，一次只能保存有限数量的信息，但在动物模型中对其潜在神经机制的研究一直以需要保留单个记忆项目的范式为主导。在人类中，视觉工作记忆的信息处理局限性已通过顺序比较程序进行了广泛研究，在该程序中，受试者在保持间隔后检测多项目阵列中的变化。在这里，我们采用这种方法来研究猕猴的工作记忆能力。我们训练了两只雌性恒河猴（猕猴）执行变化检测任务，在该任务中，它们需要在1秒的保持间隔后，通过眼跳运动报告阵列中几个项目（两到五个彩色刺激）中的哪一个颜色发生了变化。表现随着集合大小的增加而逐渐下降，但始终超过随机概率。这些结果表明，猴子具备足够的信息处理能力来执行需要同时维持多个项目记忆表征的视觉工作记忆任务，并验证了这个动物模型可用于研究多个记忆项目临时保留背后的神经机制。
