Institute of Science and Technology of Cognition, CNR Rome, Rome, Italy.
PLoS One. 2011;6(11):e27652. doi: 10.1371/journal.pone.0027652. Epub 2011 Nov 28.
The inferior part of the parietal lobe (IPL) is known to play a very important role in sensorimotor integration. Neurons in this region code goal-related motor acts performed with the mouth, with the hand and with the arm. It has been demonstrated that most IPL motor neurons coding a specific motor act (e.g., grasping) show markedly different activation patterns according to the final goal of the action sequence in which the act is embedded (grasping for eating or grasping for placing). Some of these neurons (parietal mirror neurons) show a similar selectivity also during the observation of the same action sequences when executed by others. Thus, it appears that the neuronal response occurring during the execution and the observation of a specific grasping act codes not only the executed motor act, but also the agent's final goal (intention).In this work we present a biologically inspired neural network architecture that models mechanisms of motor sequences execution and recognition. In this network, pools composed of motor and mirror neurons that encode motor acts of a sequence are arranged in form of action goal-specific neuronal chains. The execution and the recognition of actions is achieved through the propagation of activity bursts along specific chains modulated by visual and somatosensory inputs.The implemented spiking neuron network is able to reproduce the results found in neurophysiological recordings of parietal neurons during task performance and provides a biologically plausible implementation of the action selection and recognition process.Finally, the present paper proposes a mechanism for the formation of new neural chains by linking together in a sequential manner neurons that represent subsequent motor acts, thus producing goal-directed sequences.
顶叶下部分（IPL）已知在感觉运动整合中起着非常重要的作用。该区域的神经元对用嘴、手和手臂执行的与目标相关的运动行为进行编码。已经证明，编码特定运动行为（例如，抓握）的大多数 IPL 运动神经元根据其嵌入的动作序列的最终目标表现出明显不同的激活模式（例如，用于进食的抓握或用于放置的抓握）。其中一些神经元（顶叶镜像神经元）在观察其他人执行相同的动作序列时也表现出类似的选择性。因此，似乎在执行和观察特定抓握动作期间发生的神经元反应不仅编码执行的运动动作，而且还编码执行者的最终目标（意图）。
在这项工作中，我们提出了一种受生物启发的神经网络架构，该架构模拟了运动序列执行和识别的机制。在该网络中，由编码序列运动行为的运动神经元和镜像神经元组成的池以特定动作目标的神经元链的形式排列。动作的执行和识别是通过沿特定链传播活动爆发来实现的，该爆发受到视觉和躯体感觉输入的调制。
实现的尖峰神经元网络能够再现顶叶神经元在任务执行期间的神经生理学记录中发现的结果，并为动作选择和识别过程提供了一种合理的生物学实现。
最后，本文提出了一种通过以顺序方式将代表后续运动行为的神经元连接在一起形成新的神经链的机制，从而产生目标导向的序列。
