摘要：研究发现，用所谓的“工作”记忆保存信息的能力可能同时受到大脑左侧和右侧的限制。Timothy Buschman及其同事研究了神经基础发现：人在工作记忆中平均每次只能保留大约4个东西的这一纪录。这组作者在猴子瞥见计算机屏幕显示两个、三个或四个彩色方块的时候同时记录了这些猴子大脑的前额叶和顶叶皮层的神经元的活动。在短暂的休息之后，让这些猴子看了相同的画面，但其中一个方块的颜色不同了。和人类一样，猴子在它们的表现变差之前（即正常情况下）在工作记忆中只能保存平均4个彩色方块。此外，神经记录表明这些猴子局限于在从左半和右半视觉分别回忆起2个物体，而且这种限制因素出现在记忆编码的时候，而不是出现在记忆提取的时候。这些发现提示，大脑的两个皮层半球——它们分别“看到”左半和右半视场——依赖于各自独立的神经信息池。这组科研人员提出，这些发现可能对于开发改善认知能力的大脑游戏有意义，而且可能对于设计把提示信息投射到一个透明屏幕上的显示器有意义。
生物探索推荐英文原文
Memory constrained by both sides of brain
The ability to preserve information in so-called "working" memory can be limited by both the right and left sides of the brain, research finds. Timothy Buschman and colleagues investigated the neural underpinnings for the well-documented finding that the average person can only retain about four items at a time in working memory. The authors simultaneously recorded the firing of neurons in the prefrontal and parietal cortices of the monkey brain as the animals glimpsed a computer screen displaying either two, three, four, or five colored squares. After a brief rest, the monkeys were shown the same display but with one square colored differently. Monkeys received a reward for glancing toward the single changed square. As with humans, monkeys could only hold an average of four colored squares in working memory before their performance suffered. Additionally, neural recordings revealed that the monkeys were limited to recalling two objects each from the right and the left halves of vision and that the limiting factor occurred during memory encoding, not during memory retrieval. The findings suggest that the brain's two cerebral hemispheres, which "see" either the right or left half of the field of vision, rely on independent pools of neural information. The findings may have implications for the development of brain games to improve cognition and for the design of "heads-up" displays that project information onto a transparent screen, the researchers suggest.
生物探索推荐英文论文摘要：
Neural substrates of cognitive capacity limitations
Abstract
Cognition has a severely limited capacity: Adult humans can retain only about four items “in mind”. This limitation is fundamental to human brain function: Individual capacity is highly correlated with intelligence measures and capacity is reduced in neuropsychiatric diseases. Although human capacity limitations are well studied, their mechanisms have not been investigated at the single-neuron level. Simultaneous recordings from monkey parietal and frontal cortex revealed that visual capacity limitations occurred immediately upon stimulus encoding and in a bottom-up manner. Capacity limitations were found to reflect a dual model of working memory. The left and right halves of visual space had independent capacities and thus are discrete resources. However, within each hemifield, neural information about successfully remembered objects was reduced by adding further objects, indicating that resources are shared. Together, these results suggest visual capacity limitation is due to discrete, slot-like, resources, each containing limited pools of neural information that can be divided among objects.
