Department of Neurology, Barrow Neurological Institute, Phoenix, Arizona, USA.
J Neurophysiol. 2011 Jun;105(6):2874-84. doi: 10.1152/jn.00977.2010. Epub 2011 Apr 6.
A large number of studies have demonstrated that structures within the medial temporal lobe, such as the hippocampus, are intimately involved in declarative memory for objects and people. Although these items are abstractions of the visual scene, specific visual details can change the speed and accuracy of their recall. By recording from 415 neurons in the hippocampus and amygdala of human epilepsy patients as they viewed images drawn from 10 image categories, we showed that the firing rates of 8% of these neurons encode image illuminance and contrast, low-level properties not directly pertinent to task performance, whereas in 7% of the neurons, firing rates encode the category of the item depicted in the image, a high-level property pertinent to the task. This simultaneous representation of high- and low-level image properties within the same brain areas may serve to bind separate aspects of visual objects into a coherent percept and allow episodic details of objects to influence mnemonic performance.
大量研究表明，内侧颞叶（如海马体）内的结构与物体和人物的陈述性记忆密切相关。尽管这些物品是视觉场景的抽象，但特定的视觉细节可以改变它们的回忆速度和准确性。通过记录 10 个图像类别中人类癫痫患者的海马体和杏仁核的 415 个神经元，我们发现这些神经元中 8%的神经元的放电率编码图像的照度和对比度，这些都是与任务表现无关的低级属性，而在 7%的神经元中，放电率编码图像中所描绘物品的类别，这是与任务相关的高级属性。在同一大脑区域内同时表示高低水平的图像属性，可能有助于将视觉对象的不同方面结合成一个连贯的感知，并允许对象的情景细节影响记忆表现。
