Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5, Canada.
Philos Trans A Math Phys Eng Sci. 2010 Jan 28;368(1911):455-67. doi: 10.1098/rsta.2009.0229.
A neural field model with multiple cell-to-cell feedback connections is investigated. Our model incorporates populations of ON and OFF cells, receiving sensory inputs with direct and inverted polarity, respectively. Oscillatory responses to spatially localized stimuli are found to occur via Andronov-Hopf bifurcations of stationary activity. We explore the impact of multiple delayed feedback components as well as additional excitatory and/or inhibitory non-delayed recurrent signals on the instability threshold. Paradoxically, instantaneous excitatory recurrent terms are found to enhance network responsiveness by reducing the oscillatory response threshold, allowing smaller inputs to trigger oscillatory activity. Instantaneous inhibitory components do the opposite. The frequency of these response oscillations is further shaped by the polarity of the non-delayed terms.
研究了具有多个细胞间反馈连接的神经场模型。我们的模型包含 ON 和 OFF 细胞群体，分别接收具有直接和反转极性的感觉输入。通过定态活动的 Andronov-Hopf 分岔，发现对空间局部刺激的振荡响应。我们探讨了多个延迟反馈分量以及额外的兴奋性和/或抑制性非延迟递归信号对不稳定性阈值的影响。矛盾的是，发现瞬时兴奋性递归项通过降低振荡响应阈值来增强网络响应能力，从而允许较小的输入触发振荡活动。瞬时抑制性分量则相反。这些响应振荡的频率还受到非延迟项极性的影响。
