Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 México, D.F., Mexico.
Prog Neurobiol. 2013 Apr;103:41-75. doi: 10.1016/j.pneurobio.2012.03.007. Epub 2012 Mar 28.
A fundamental problem in neurobiology is to understand how brain circuits represent sensory information and how such representations give rise to perception, memory and decision-making. We demonstrate that a sensory stimulus engages multiple areas of the cerebral cortex, including primary sensory, prefrontal, premotor and motor cortices. As information transverses the cortical circuits it shows progressively more relation to perception, memory and decision reports. In particular, we show how somatosensory areas on the parietal lobe generate a parameterized representation of a tactile stimulus. This representation is maintained in working memory by prefrontal and premotor areas of the frontal lobe. The presentation of a second stimulus, that monkeys are trained to compare with the first, generates decision-related activity reflecting which stimulus had the higher frequency. Importantly, decision-related activity is observed across several cortical circuits including prefrontal, premotor and parietal cortices. Sensory information is encoded by neuronal populations with opposite tuning, and suggests that a simple subtraction operation could be the underlying mechanism by which past and present sensory information is compared to generate perceptual decisions.
神经生物学的一个基本问题是理解大脑回路如何表示感觉信息，以及这种表示如何产生感知、记忆和决策。我们证明，感觉刺激会激活大脑皮层的多个区域，包括初级感觉、前额叶、前运动和运动皮层。随着信息在皮层回路中传递，它与感知、记忆和决策报告的关系越来越密切。特别是，我们展示了顶叶上的躯体感觉区域如何生成触觉刺激的参数化表示。这种表示由额叶的前额叶和前运动区域在工作记忆中维持。呈现第二个刺激，猴子被训练将其与第一个刺激进行比较，会产生与决策相关的活动，反映出哪个刺激的频率更高。重要的是，决策相关的活动在包括前额叶、前运动和顶叶皮层在内的几个皮层回路中都有观察到。感觉信息由具有相反调谐的神经元群体进行编码，并表明简单的减法运算可能是比较过去和现在的感觉信息以产生感知决策的潜在机制。
