Hampson Robert E, Pons Tim P, Stanford Terrence R, Deadwyler Sam A
Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
Proc Natl Acad Sci U S A. 2004 Mar 2;101(9):3184-9. doi: 10.1073/pnas.0400162101. Epub 2004 Feb 20.
The mammalian hippocampus processes sensory information into memory. The neurobiological basis of this representation, as well as the type of information that is encoded, is central to understanding how memories are formed. Normally, there is an infinite amount of information that could be encoded for any given stimulus. Thus, the question arises as to how the hippocampus selects and encodes features of a given stimulus. Here, we show that neurons in the hippocampus of the monkey appear to categorize types of visual stimuli presented in a delayed-match-to-sample memory task. By extracting unique combinations of features, these category cells are able to encode aspects of behaviorally important images instead of encoding all visual details. The subject is then able to rapidly select an appropriate response to that stimulus when distracting stimuli are presented simultaneously, thereby facilitating performance. Moreover, across animals, this specific type of encoding differed considerably. Just as in humans, different monkeys attended to and selected different aspects of the same stimulus image, most likely reflecting different histories, strategies, and expectations residing within individual hippocampal networks.
哺乳动物的海马体将感官信息处理为记忆。这种表征的神经生物学基础以及所编码信息的类型，对于理解记忆是如何形成的至关重要。通常，对于任何给定的刺激，都有无限量的信息可以被编码。因此，就出现了海马体如何选择和编码给定刺激特征的问题。在这里，我们表明，猴子海马体中的神经元似乎对延迟匹配样本记忆任务中呈现的视觉刺激类型进行了分类。通过提取特征的独特组合，这些类别细胞能够编码行为上重要图像的各个方面，而不是编码所有视觉细节。当同时呈现干扰刺激时，受试者能够迅速对该刺激做出适当反应，从而提高表现。此外，在不同动物之间，这种特定类型的编码差异很大。就像在人类中一样，不同的猴子关注并选择同一刺激图像的不同方面，这很可能反映了个体海马体网络中不同的经历、策略和期望。
